Security Bulletin
Summary
IBM DataPower Gateway has addressed multiple vulnerabilities in OS kernel in version 11.0.0.3
Vulnerability Details
CVEID: CVE-2026-46116
DESCRIPTION: In the Linux kernel, the following vulnerability has been resolved:
xfrm: defensively unhash xfrm_state lists in __xfrm_state_delete
KASAN reproduces a slab-use-after-free in __xfrm_state_delete()'s
hlist_del_rcu calls under syzkaller load on linux-6.12.y stable
(reproduced on 6.12.47, also reachable via the same code path on
torvalds/master and on the ipsec tree). Nine unique signatures cluster
in the xfrm_state lifecycle, the load-bearing one being:
BUG: KASAN: slab-use-after-free in __hlist_del include/linux/list.h:990 [inline]
BUG: KASAN: slab-use-after-free in hlist_del_rcu include/linux/rculist.h:516 [inline]
BUG: KASAN: slab-use-after-free in __xfrm_state_delete net/xfrm/xfrm_state.c
Write of size 8 at addr ffff8881198bcb70 by task kworker/u8:9/435
Workqueue: netns cleanup_net
Call Trace:
__hlist_del / hlist_del_rcu
__xfrm_state_delete
xfrm_state_delete
xfrm_state_flush
xfrm_state_fini
ops_exit_list
cleanup_net
The other observed signatures hit the same slab object from
__xfrm_state_lookup, xfrm_alloc_spi, __xfrm_state_insert and an OOB
write variant of __xfrm_state_delete, all on the byseq/byspi
hash chains.
__xfrm_state_delete() guards its byseq and byspi unhashes with
value-based predicates:
if (x-km.seq)
hlist_del_rcu(&x-byseq);
if (x-id.spi)
hlist_del_rcu(&x-byspi);
while everywhere else in the file (e.g. state_cache, state_cache_input)
the safer hlist_unhashed() check is used. xfrm_alloc_spi() sets
x-id.spi = newspi inside xfrm_state_lock and then immediately inserts
into byspi, but a path that observes x-id.spi != 0 outside of
xfrm_state_lock can still skip-or-hit the byspi unhash inconsistently
with whether x is actually on the list. The same holds for x-km.seq
versus byseq, and the bydst/bysrc unhashes have no predicate at all,
so a second __xfrm_state_delete() on the same object writes through
LIST_POISON pprev.
The defensive change here:
- Use hlist_del_init_rcu() instead of hlist_del_rcu() on bydst,
bysrc, byseq and byspi so a second deletion is a no-op rather
than a write through LIST_POISON pprev. The byseq/byspi nodes
are already initialised in xfrm_state_alloc().
- Test hlist_unhashed() rather than the value predicate for
byseq/byspi, so the unhash decision tracks list state rather than
mutable scalar fields.
Empirical verification: applied this patch on top of v6.12.47, rebuilt,
and re-ran the same syzkaller harness for 1h16m on a previously-crashy
configuration that produced ~100 hits each of slab-use-after-free
Read in xfrm_alloc_spi / Read in __xfrm_state_lookup / Write in
__xfrm_state_delete. After the patch, 7.1M execs across 32 VMs at
~1550 exec/sec produced zero xfrm_state UAF/OOB hits. /proc/slabinfo
confirms the xfrm_state slab is actively allocated and freed during
the run (~143 KiB resident), so the fuzzer is still exercising those
code paths -- they just no longer crash.
Reproduction:
- Linux 6.12.47 x86_64 + KASAN_GENERIC + KASAN_INLINE + KCOV
- syzkaller @ 746545b8b1e4c3a128db8652b340d3df90ce61db
- 32 QEMU/KVM VMs x 2 vCPU on AWS c5.metal bare metal
- 9 unique signatures collected in ~9h, all within xfrm_state
lifecycle
CWE: CWE-416: Use After Free
CVSS Source: Linux
CVSS Base score: 7.8
CVSS Vector: (CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H)
CVEID: CVE-2026-46259
DESCRIPTION: In the Linux kernel, the following vulnerability has been resolved:
procfs: fix missing RCU protection when reading real_parent in do_task_stat()
When reading /proc/[pid]/stat, do_task_stat() accesses task-real_parent
without proper RCU protection, which leads to:
cpu 0 cpu 1
----- -----
do_task_stat
var = task-real_parent
release_task
call_rcu(delayed_put_task_struct)
task_tgid_nr_ns(var)
rcu_read_lock --- Too late to protect task-real_parent!
task_pid_ptr --- UAF!
rcu_read_unlock
This patch uses task_ppid_nr_ns() instead of task_tgid_nr_ns() to add
proper RCU protection for accessing task-real_parent.
CVSS Source: Linux
CVSS Base score: 7.8
CVSS Vector: (CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H)
CVEID: CVE-2026-53006
DESCRIPTION: In the Linux kernel, the following vulnerability has been resolved:
ipv6: fix possible UAF in icmpv6_rcv()
Caching saddr and daddr before pskb_pull() is problematic
since skb-head can change.
Remove these temporary variables:
- We only access &ipv6_hdr(skb)-saddr and &ipv6_hdr(skb)-daddr
when net_dbg_ratelimited() is called in the slow path.
- Avoid potential future misuse after pskb_pull() call.
CWE: CWE-416: Use After Free
CVSS Source: Linux
CVSS Base score: 9.8
CVSS Vector: (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H)
CVEID: CVE-2025-68211
DESCRIPTION: In the Linux kernel, the following vulnerability has been resolved:
ksm: use range-walk function to jump over holes in scan_get_next_rmap_item
Currently, scan_get_next_rmap_item() walks every page address in a VMA to
locate mergeable pages. This becomes highly inefficient when scanning
large virtual memory areas that contain mostly unmapped regions, causing
ksmd to use large amount of cpu without deduplicating much pages.
This patch replaces the per-address lookup with a range walk using
walk_page_range(). The range walker allows KSM to skip over entire
unmapped holes in a VMA, avoiding unnecessary lookups. This problem was
previously discussed in [1].
Consider the following test program which creates a 32 TiB mapping in the
virtual address space but only populates a single page:
#include unistd.h
#include stdio.h
#include sys/mman.h
/* 32 TiB */
const size_t size = 32ul * 1024 * 1024 * 1024 * 1024;
int main() {
char *area = mmap(NULL, size, PROT_READ | PROT_WRITE,
MAP_NORESERVE | MAP_PRIVATE | MAP_ANON, -1, 0);
if (area == MAP_FAILED) {
perror("mmap() failed\n");
return -1;
}
/* Populate a single page such that we get an anon_vma. */
*area = 0;
/* Enable KSM. */
madvise(area, size, MADV_MERGEABLE);
pause();
return 0;
}
$ ./ksm-sparse &
$ echo 1 /sys/kernel/mm/ksm/run
Without this patch ksmd uses 100% of the cpu for a long time (more then 1
hour in my test machine) scanning all the 32 TiB virtual address space
that contain only one mapped page. This makes ksmd essentially deadlocked
not able to deduplicate anything of value. With this patch ksmd walks
only the one mapped page and skips the rest of the 32 TiB virtual address
space, making the scan fast using little cpu.
CVSS Source: NVD
CVSS Base score: 5.5
CVSS Vector: (CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H)
CVEID: CVE-2026-53131
DESCRIPTION: In the Linux kernel, the following vulnerability has been resolved:
netfilter: require Ethernet MAC header before using eth_hdr()
`ip6t_eui64`, `xt_mac`, the `bitmap:ip,mac`, `hash:ip,mac`, and
`hash:mac` ipset types, and `nf_log_syslog` access `eth_hdr(skb)`
after either assuming that the skb is associated with an Ethernet
device or checking only that the `ETH_HLEN` bytes at
`skb_mac_header(skb)` lie between `skb-head` and `skb-data`.
Make these paths first verify that the skb is associated with an
Ethernet device, that the MAC header was set, and that it spans at
least a full Ethernet header before accessing `eth_hdr(skb)`.
CVSS Source: Linux
CVSS Base score: 9.4
CVSS Vector: (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:H)
CVEID: CVE-2026-74581
DESCRIPTION: In the Linux kernel, the following vulnerability has been resolved:
net: ipv6: clear suppressed fib6 rule result
fib6_rule_suppress() drops a suppressed route with ip6_rt_put_flags(),
but leaves res-rt6 pointing at the released rt6_info.
If no later rule supplies a replacement, fib6_rule_lookup() still sees
res.rt6 and returns that stale dst to its caller. A suppressing rule can
therefore leak a released route back to rt6_lookup(), and the next put
hits rcuref_put_slowpath() from dst_release().
Clear res-rt6 when suppressing the route so suppressed lookups fall
through to the null dst instead of reusing the released one.
CVSS Source: Linux
CVSS Base score: 9.8
CVSS Vector: (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H)
CVEID: CVE-2026-23110
DESCRIPTION: In the Linux kernel, the following vulnerability has been resolved:
scsi: core: Wake up the error handler when final completions race against each other
The fragile ordering between marking commands completed or failed so
that the error handler only wakes when the last running command
completes or times out has race conditions. These race conditions can
cause the SCSI layer to fail to wake the error handler, leaving I/O
through the SCSI host stuck as the error state cannot advance.
First, there is an memory ordering issue within scsi_dec_host_busy().
The write which clears SCMD_STATE_INFLIGHT may be reordered with reads
counting in scsi_host_busy(). While the local CPU will see its own
write, reordering can allow other CPUs in scsi_dec_host_busy() or
scsi_eh_inc_host_failed() to see a raised busy count, causing no CPU to
see a host busy equal to the host_failed count.
This race condition can be prevented with a memory barrier on the error
path to force the write to be visible before counting host busy
commands.
Second, there is a general ordering issue with scsi_eh_inc_host_failed(). By
counting busy commands before incrementing host_failed, it can race with a
final command in scsi_dec_host_busy(), such that scsi_dec_host_busy() does
not see host_failed incremented but scsi_eh_inc_host_failed() counts busy
commands before SCMD_STATE_INFLIGHT is cleared by scsi_dec_host_busy(),
resulting in neither waking the error handler task.
This needs the call to scsi_host_busy() to be moved after host_failed is
incremented to close the race condition.
CWE: CWE-362: Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')
CVSS Source: NVD
CVSS Base score: 4.7
CVSS Vector: (CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H)
CVEID: CVE-2026-52991
DESCRIPTION: In the Linux kernel, the following vulnerability has been resolved:
sched/psi: fix race between file release and pressure write
A potential race condition exists between pressure write and cgroup file
release regarding the priv member of struct kernfs_open_file, which
triggers the uaf reported in [1].
Consider the following scenario involving execution on two separate CPUs:
CPU0 CPU1
==== ====
vfs_rmdir()
kernfs_iop_rmdir()
cgroup_rmdir()
cgroup_kn_lock_live()
cgroup_destroy_locked()
cgroup_addrm_files()
cgroup_rm_file()
kernfs_remove_by_name()
kernfs_remove_by_name_ns()
vfs_write() __kernfs_remove()
new_sync_write() kernfs_drain()
kernfs_fop_write_iter() kernfs_drain_open_files()
cgroup_file_write() kernfs_release_file()
pressure_write() cgroup_file_release()
ctx = of-priv;
kfree(ctx);
of-priv = NULL;
cgroup_kn_unlock()
cgroup_kn_lock_live()
cgroup_get(cgrp)
cgroup_kn_unlock()
if (ctx-psi.trigger) // here, trigger uaf for ctx, that is of-priv
The cgroup_rmdir() is protected by the cgroup_mutex, it also safeguards
the memory deallocation of of-priv performed within cgroup_file_release().
However, the operations involving of-priv executed within pressure_write()
are not entirely covered by the protection of cgroup_mutex. Consequently,
if the code in pressure_write(), specifically the section handling the
ctx variable executes after cgroup_file_release() has completed, a uaf
vulnerability involving of-priv is triggered.
Therefore, the issue can be resolved by extending the scope of the
cgroup_mutex lock within pressure_write() to encompass all code paths
involving of-priv, thereby properly synchronizing the race condition
occurring between cgroup_file_release() and pressure_write().
And, if an live kn lock can be successfully acquired while executing
the pressure write operation, it indicates that the cgroup deletion
process has not yet reached its final stage; consequently, the priv
pointer within open_file cannot be NULL. Therefore, the operation to
retrieve the ctx value must be moved to a point *after* the live kn
lock has been successfully acquired.
In another situation, specifically after entering cgroup_kn_lock_live()
but before acquiring cgroup_mutex, there exists a different class of
race condition:
CPU0: write memory.pressure CPU1: write cgroup.pressure=0
=========================== =============================
kernfs_fop_write_iter()
kernfs_get_active_of(of)
pressure_write()
cgroup_kn_lock_live(memory.pressure)
cgroup_tryget(cgrp)
kernfs_break_active_protection(kn)
... blocks on cgroup_mutex
cgroup_pressure_write()
cgroup_kn_lock_live(cgroup.pressure)
cgroup_file_show(memory.pressure, false)
kernfs_show(false)
kernfs_drain_open_files()
cgroup_file_release(of)
kfree(ctx)
of-priv = NULL
cgroup_kn_unlock()
... acquires cgroup_mutex
ctx = of-priv; // may now be NULL
if (ctx-psi.trigger) // NULL dereference
Consequently, there is a possibility that of-priv is NULL, the pressure
write needs to check for this.
Now that the scope of the cgroup_mutex has been expanded, the original
explicit cgroup_get/put operations are no longer necessary, this is
because acquiring/releasing the live kn lock inherently executes a
cgroup get/put operation.
[1]
BUG: KASAN: slab-use-after-free in pressure_write+0xa4/0x210 kernel/cgroup/cgroup.c:4011
Call Trace:
pressure_write+0xa4/0x210 kernel/cgroup/cgroup.c:4011
cgroup_file_write+0x36f/0x790 kernel/cgroup/cgroup.c:43
---truncated---
CWE: CWE-362: Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')
CVSS Source: Linux
CVSS Base score: 7.8
CVSS Vector: (CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H)
CVEID: CVE-2026-53189
DESCRIPTION: In the Linux kernel, the following vulnerability has been resolved:
mm/huge_memory: update file PMD counter before folio_put()
__split_huge_pmd_locked() updates the file/shmem RSS counter after
dropping the PMD mapping's folio reference. If folio_put() drops the last
reference, mm_counter_file() can later read freed folio state via
folio_test_swapbacked().
Move the counter update before folio_put().
CVSS Source: Linux
CVSS Base score: 7.8
CVSS Vector: (CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H)
CVEID: CVE-2026-63952
DESCRIPTION: In the Linux kernel, the following vulnerability has been resolved:
memfd: deny writeable mappings when implying SEAL_WRITE
When SEAL_EXEC is added, SEAL_WRITE is implied to make W^X. But the
implied seal is set after the check that makes sure the memfd can not have
any writable mappings. This means one can use SEAL_EXEC to apply
SEAL_WRITE while having writeable mappings.
This breaks the contract that SEAL_WRITE provides and can be used by an
attacker to pass a memfd that appears to be write sealed but can still be
modified arbitrarily.
Fix this by adding the implied seals before the call for
mapping_deny_writable() is done.
CVSS Source: Linux
CVSS Base score: 8.4
CVSS Vector: (CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:N)
CVEID: CVE-2026-64560
DESCRIPTION: In the Linux kernel, the following vulnerability has been resolved:
posix-cpu-timers: Prevent UAF caused by non-leader exec() race
Wongi and Jungwoo decoded and reported a non-leader exec() related race
which can result in an UAF:
sys_timer_delete() exec()
posix_cpu_timer_del()
// Observes old leader
p = pid_task(pid, pid_type); de_thread()
switch_leader();
release_task(old_leader)
__exit_signal(old_leader)
sighand = lock(old_leader, sighand);
posix_cpu_timers*_exit();
sighand = lock_task_sighand(p) unhash_task(old_leader);
sh = lock(p, sighand) old_leader-sighand = NULL;
unlock(sighand);
(p-sighand == NULL)
unlock(sh)
return NULL;
// Returns without action
if(!sighand)
return 0;
free_posix_timer();
This is "harmless" unless the deleted timer was armed and enqueued in
p-signal because on exec() a TGID targeted timer is inherited.
As sys_timer_delete() freed the underlying posix timer object
run_posix_cpu_timers() or any timerqueue related add/delete operations on
other timers will access the freed object's timerqueue node, which results
in an UAF.
There is a similar problem vs. posix_cpu_timer_set(). For regular posix
timers it just transiently returns -ESRCH to user space, but for the use
case in do_cpu_nanosleep() it's the same UAF just that the k_itimer is
allocated on the stack.
Also posix_cpu_timer_rearm() fails to rearm the timer, which means it stops
to expire.
While debating solutions Frederic pointed out another problem:
posix_cpu_timer_del(tmr)
__exit_signal(p)
posix_cpu_timers*_exit(p);
unhash_task(p);
p-sighand = NULL;
sh = lock_task_sighand(p)
sighand = p-sighand;
if (!sighand)
return NULL;
lock(sighand);
if (!sh)
WARN_ON_ONCE(timer_queued(tmr));
On weakly ordered architectures it is not guaranteed that
posix_cpu_timer_del() will observe the stores in posix_cpu_timers*_exit()
when p-sighand is observed as NULL, which means the WARN() can be a false
positive.
Solve these issues by:
1) Changing the store in __exit_signal() to smp_store_release().
2) Adding a smp_acquire__after_ctrl_dep() into the !sighand path
of lock_task_sighand().
3) Creating a helper function for looking up the task and locking sighand
which does not return when sighand == NULL. Instead it retries the
task lookup and only if that fails it gives up.
4) Using that helper in the three affected functions.
#1/#2 ensures that the reader side which observes sighand == NULL also
observes all preceeding stores, i.e. the stores in posix_cpu_timers*_exit()
and the ones in unhash_task().
#3 ensures that the above described non-leader exec() situation is handled
gracefully. When the task lookup returns the old leader, but sighand ==
NULL then it retries. In the non-leader exec() case the subsequent task
lookup will observe the new leader due to #1/#2. In normal exit() scenarios
the subsequent lookup fails.
When the task lookup fails, the function also checks whether the timer is
still enqueued and issues a warning if that's the case. Unfortunately there
is nothing which can be done about it, but as the task is already not
longer visible the timer should not be accessed anymore. This check also
requires memory ordering, which is not provided when the first lookup
fails. To achieve that the check is preceeded by a smp_rmb() which pairs
with the smp_wmb() in write_seqlock() in __exit_signal(). That ensures that
the stores in posix_cpu_timers*_exit() are visible.
The history of the non-leader exec() issue goes back to the early days of
posix CPU timers, which stored a pointer to the group leader task in the
timer. That obviously fails when a non-leader exec() switches the leader.
commit e0a70217107e ("posix-cpu-timers: workaround to suppress the problems
with mt exec") added a temporary workaround for that in 2010 which surv
---truncated---
CVSS Source: Linux
CVSS Base score: 7.8
CVSS Vector: (CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H)
CVEID: CVE-2025-71066
DESCRIPTION: In the Linux kernel, the following vulnerability has been resolved:
net/sched: ets: Always remove class from active list before deleting in ets_qdisc_change
zdi-disclosures@trendmicro.com says:
The vulnerability is a race condition between `ets_qdisc_dequeue` and
`ets_qdisc_change`. It leads to UAF on `struct Qdisc` object.
Attacker requires the capability to create new user and network namespace
in order to trigger the bug.
See my additional commentary at the end of the analysis.
Analysis:
static int ets_qdisc_change(struct Qdisc *sch, struct nlattr *opt,
struct netlink_ext_ack *extack)
{
...
// (1) this lock is preventing .change handler (`ets_qdisc_change`)
//to race with .dequeue handler (`ets_qdisc_dequeue`)
sch_tree_lock(sch);
for (i = nbands; i oldbands; i++) {
if (i = q-nstrict && q-classes[i].qdisc-q.qlen)
list_del_init(&q-classes[i].alist);
qdisc_purge_queue(q-classes[i].qdisc);
}
WRITE_ONCE(q-nbands, nbands);
for (i = nstrict; i q-nstrict; i++) {
if (q-classes[i].qdisc-q.qlen) {
// (2) the class is added to the q-active
list_add_tail(&q-classes[i].alist, &q-active);
q-classes[i].deficit = quanta[i];
}
}
WRITE_ONCE(q-nstrict, nstrict);
memcpy(q-prio2band, priomap, sizeof(priomap));
for (i = 0; i q-nbands; i++)
WRITE_ONCE(q-classes[i].quantum, quanta[i]);
for (i = oldbands; i q-nbands; i++) {
q-classes[i].qdisc = queues[i];
if (q-classes[i].qdisc != &noop_qdisc)
qdisc_hash_add(q-classes[i].qdisc, true);
}
// (3) the qdisc is unlocked, now dequeue can be called in parallel
// to the rest of .change handler
sch_tree_unlock(sch);
ets_offload_change(sch);
for (i = q-nbands; i oldbands; i++) {
// (4) we're reducing the refcount for our class's qdisc and
// freeing it
qdisc_put(q-classes[i].qdisc);
// (5) If we call .dequeue between (4) and (5), we will have
// a strong UAF and we can control RIP
q-classes[i].qdisc = NULL;
WRITE_ONCE(q-classes[i].quantum, 0);
q-classes[i].deficit = 0;
gnet_stats_basic_sync_init(&q-classes[i].bstats);
memset(&q-classes[i].qstats, 0, sizeof(q-classes[i].qstats));
}
return 0;
}
Comment:
This happens because some of the classes have their qdiscs assigned to
NULL, but remain in the active list. This commit fixes this issue by always
removing the class from the active list before deleting and freeing its
associated qdisc
Reproducer Steps
(trimmed version of what was sent by zdi-disclosures@trendmicro.com)
```
DEV="${DEV:-lo}"
ROOT_HANDLE="${ROOT_HANDLE:-1:}"
BAND2_HANDLE="${BAND2_HANDLE:-20:}" # child under 1:2
PING_BYTES="${PING_BYTES:-48}"
PING_COUNT="${PING_COUNT:-200000}"
PING_DST="${PING_DST:-127.0.0.1}"
SLOW_TBF_RATE="${SLOW_TBF_RATE:-8bit}"
SLOW_TBF_BURST="${SLOW_TBF_BURST:-100b}"
SLOW_TBF_LAT="${SLOW_TBF_LAT:-1s}"
cleanup() {
tc qdisc del dev "$DEV" root 2/dev/null
}
trap cleanup EXIT
ip link set "$DEV" up
tc qdisc del dev "$DEV" root 2/dev/null || true
tc qdisc add dev "$DEV" root handle "$ROOT_HANDLE" ets bands 2 strict 2
tc qdisc add dev "$DEV" parent 1:2 handle "$BAND2_HANDLE" \
tbf rate "$SLOW_TBF_RATE" burst "$SLOW_TBF_BURST" latency "$SLOW_TBF_LAT"
tc filter add dev "$DEV" parent 1: protocol all prio 1 u32 match u32 0 0 flowid 1:2
tc -s qdisc ls dev $DEV
ping -I "$DEV" -f -c "$PING_COUNT" -s "$PING_BYTES" -W 0.001 "$PING_DST" \
/dev/null 2&1 &
tc qdisc change dev "$DEV" root handle "$ROOT_HANDLE" ets bands 2 strict 0
tc qdisc change dev "$DEV" root handle "$ROOT_HANDLE" ets bands 2 strict 2
tc -s qdisc ls dev $DEV
tc qdisc del dev "$DEV" parent
---truncated---
CWE: CWE-362: Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')
CVSS Source: Linux
CVSS Base score: 7.8
CVSS Vector: (CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H)
CVEID: CVE-2026-43074
DESCRIPTION: In the Linux kernel, the following vulnerability has been resolved:
eventpoll: defer struct eventpoll free to RCU grace period
In certain situations, ep_free() in eventpoll.c will kfree the epi-ep
eventpoll struct while it still being used by another concurrent thread.
Defer the kfree() to an RCU callback to prevent UAF.
CWE: CWE-401: Missing Release of Memory after Effective Lifetime
CVSS Source: Linux
CVSS Base score: 7.8
CVSS Vector: (CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H)
CVEID: CVE-2026-46242
DESCRIPTION: In the Linux kernel, the following vulnerability has been resolved:
eventpoll: fix ep_remove struct eventpoll / struct file UAF
ep_remove() (via ep_remove_file()) cleared file-f_ep under
file-f_lock but then kept using @file inside the critical section
(is_file_epoll(), hlist_del_rcu() through the head, spin_unlock).
A concurrent __fput() taking the eventpoll_release() fastpath in
that window observed the transient NULL, skipped
eventpoll_release_file() and ran to f_op-release / file_free().
For the epoll-watches-epoll case, f_op-release is
ep_eventpoll_release() - ep_clear_and_put() - ep_free(), which
kfree()s the watched struct eventpoll. Its embedded -refs
hlist_head is exactly where epi-fllink.pprev points, so the
subsequent hlist_del_rcu()'s "*pprev = next" scribbles into freed
kmalloc-192 memory.
In addition, struct file is SLAB_TYPESAFE_BY_RCU, so the slot
backing @file could be recycled by alloc_empty_file() --
reinitializing f_lock and f_ep -- while ep_remove() is still
nominally inside that lock. The upshot is an attacker-controllable
kmem_cache_free() against the wrong slab cache.
Pin @file via epi_fget() at the top of ep_remove() and gate the
critical section on the pin succeeding. With the pin held @file
cannot reach refcount zero, which holds __fput() off and
transitively keeps the watched struct eventpoll alive across the
hlist_del_rcu() and the f_lock use, closing both UAFs.
If the pin fails @file has already reached refcount zero and its
__fput() is in flight. Because we bailed before clearing f_ep,
that path takes the eventpoll_release() slow path into
eventpoll_release_file() and blocks on ep-mtx until the waiter
side's ep_clear_and_put() drops it. The bailed epi's share of
ep-refcount stays intact, so the trailing ep_refcount_dec_and_test()
in ep_clear_and_put() cannot free the eventpoll out from under
eventpoll_release_file(); the orphaned epi is then cleaned up
there.
A successful pin also proves we are not racing
eventpoll_release_file() on this epi, so drop the now-redundant
re-check of epi-dying under f_lock. The cheap lockless
READ_ONCE(epi-dying) fast-path bailout stays.
CWE: CWE-416: Use After Free
CVSS Source: Linux
CVSS Base score: 7.8
CVSS Vector: (CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H)
CVEID: CVE-2026-53266
DESCRIPTION: In the Linux kernel, the following vulnerability has been resolved:
netfilter: bridge: make ebt_snat ARP rewrite writable
The ebtables SNAT target keeps the Ethernet source address rewrite
behind skb_ensure_writable(skb, 0). This is intentional: at the bridge
ebtables hooks the Ethernet header is addressed through
skb_mac_header()/eth_hdr(), while skb-data points at the Ethernet
payload. Asking skb_ensure_writable() for ETH_HLEN bytes would check
the payload, not the Ethernet header, and would reintroduce the small
packet regression fixed by commit 63137bc5882a.
However, the optional ARP sender hardware address rewrite is different.
It writes through skb_store_bits() at an offset relative to skb-data:
skb_store_bits(skb, sizeof(struct arphdr), info-mac, ETH_ALEN)
skb_header_pointer() only safely reads the ARP header; it does not make
the later sender hardware address range writable. If that range is
still held in a nonlinear skb fragment backed by a splice-imported file
page, skb_store_bits() maps the frag page and copies the new MAC address
directly into it.
Ensure the ARP SHA range is writable before reading the ARP header and
before calling skb_store_bits().
CWE: CWE-787: Out-of-bounds Write
CVSS Source: Linux
CVSS Base score: 8.8
CVSS Vector: (CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H)
CVEID: CVE-2026-22979
DESCRIPTION: In the Linux kernel, the following vulnerability has been resolved:
net: fix memory leak in skb_segment_list for GRO packets
When skb_segment_list() is called during packet forwarding, it handles
packets that were aggregated by the GRO engine.
Historically, the segmentation logic in skb_segment_list assumes that
individual segments are split from a parent SKB and may need to carry
their own socket memory accounting. Accordingly, the code transfers
truesize from the parent to the newly created segments.
Prior to commit ed4cccef64c1 ("gro: fix ownership transfer"), this
truesize subtraction in skb_segment_list() was valid because fragments
still carry a reference to the original socket.
However, commit ed4cccef64c1 ("gro: fix ownership transfer") changed
this behavior by ensuring that fraglist entries are explicitly
orphaned (skb-sk = NULL) to prevent illegal orphaning later in the
stack. This change meant that the entire socket memory charge remained
with the head SKB, but the corresponding accounting logic in
skb_segment_list() was never updated.
As a result, the current code unconditionally adds each fragment's
truesize to delta_truesize and subtracts it from the parent SKB. Since
the fragments are no longer charged to the socket, this subtraction
results in an effective under-count of memory when the head is freed.
This causes sk_wmem_alloc to remain non-zero, preventing socket
destruction and leading to a persistent memory leak.
The leak can be observed via KMEMLEAK when tearing down the networking
environment:
unreferenced object 0xffff8881e6eb9100 (size 2048):
comm "ping", pid 6720, jiffies 4295492526
backtrace:
kmem_cache_alloc_noprof+0x5c6/0x800
sk_prot_alloc+0x5b/0x220
sk_alloc+0x35/0xa00
inet6_create.part.0+0x303/0x10d0
__sock_create+0x248/0x640
__sys_socket+0x11b/0x1d0
Since skb_segment_list() is exclusively used for SKB_GSO_FRAGLIST
packets constructed by GRO, the truesize adjustment is removed.
The call to skb_release_head_state() must be preserved. As documented in
commit cf673ed0e057 ("net: fix fraglist segmentation reference count
leak"), it is still required to correctly drop references to SKB
extensions that may be overwritten during __copy_skb_header().
CWE: CWE-401: Missing Release of Memory after Effective Lifetime
CVSS Source: NVD
CVSS Base score: 5.5
CVSS Vector: (CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H)
CVEID: CVE-2026-43499
DESCRIPTION: In the Linux kernel, the following vulnerability has been resolved:
rtmutex: Use waiter::task instead of current in remove_waiter()
remove_waiter() is used by the slowlock paths, but it is also used for
proxy-lock rollback in rt_mutex_start_proxy_lock() when invoked from
futex_requeue().
In the latter case waiter::task is not current, but remove_waiter()
operates on current for the dequeue operation. That results in several
problems:
1) the rbtree dequeue happens without waiter::task::pi_lock being held
2) the waiter task's pi_blocked_on state is not cleared, which leaves a
dangling pointer primed for UAF around.
3) rt_mutex_adjust_prio_chain() operates on the wrong top priority waiter
task
Use waiter::task instead of current in all related operations in
remove_waiter() to cure those problems.
[ tglx: Fixup rt_mutex_adjust_prio_chain(), add a comment and amend the
changelog ]
CWE: CWE-416: Use After Free
CVSS Source: Linux
CVSS Base score: 7.8
CVSS Vector: (CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H)
CVEID: CVE-2025-38653
DESCRIPTION: In the Linux kernel, the following vulnerability has been resolved:
proc: use the same treatment to check proc_lseek as ones for proc_read_iter et.al
Check pde-proc_ops-proc_lseek directly may cause UAF in rmmod scenario.
It's a gap in proc_reg_open() after commit 654b33ada4ab("proc: fix UAF in
proc_get_inode()"). Followed by AI Viro's suggestion, fix it in same
manner.
CWE: CWE-416: Use After Free
CVSS Source: NVD
CVSS Base score: 7.8
CVSS Vector: (CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H)
CVEID: CVE-2025-68183
DESCRIPTION: In the Linux kernel, the following vulnerability has been resolved:
ima: don't clear IMA_DIGSIG flag when setting or removing non-IMA xattr
Currently when both IMA and EVM are in fix mode, the IMA signature will
be reset to IMA hash if a program first stores IMA signature in
security.ima and then writes/removes some other security xattr for the
file.
For example, on Fedora, after booting the kernel with "ima_appraise=fix
evm=fix ima_policy=appraise_tcb" and installing rpm-plugin-ima,
installing/reinstalling a package will not make good reference IMA
signature generated. Instead IMA hash is generated,
# getfattr -m - -d -e hex /usr/bin/bash
# file: usr/bin/bash
security.ima=0x0404...
This happens because when setting security.selinux, the IMA_DIGSIG flag
that had been set early was cleared. As a result, IMA hash is generated
when the file is closed.
Similarly, IMA signature can be cleared on file close after removing
security xattr like security.evm or setting/removing ACL.
Prevent replacing the IMA file signature with a file hash, by preventing
the IMA_DIGSIG flag from being reset.
Here's a minimal C reproducer which sets security.selinux as the last
step which can also replaced by removing security.evm or setting ACL,
#include stdio.h
#include sys/xattr.h
#include fcntl.h
#include unistd.h
#include string.h
#include stdlib.h
int main() {
const char* file_path = "/usr/sbin/test_binary";
const char* hex_string = "030204d33204490066306402304";
int length = strlen(hex_string);
char* ima_attr_value;
int fd;
fd = open(file_path, O_WRONLY|O_CREAT|O_EXCL, 0644);
if (fd == -1) {
perror("Error opening file");
return 1;
}
ima_attr_value = (char*)malloc(length / 2 );
for (int i = 0, j = 0; i length; i += 2, j++) {
sscanf(hex_string + i, "%2hhx", &ima_attr_value[j]);
}
if (fsetxattr(fd, "security.ima", ima_attr_value, length/2, 0) == -1) {
perror("Error setting extended attribute");
close(fd);
return 1;
}
const char* selinux_value= "system_u:object_r:bin_t:s0";
if (fsetxattr(fd, "security.selinux", selinux_value, strlen(selinux_value), 0) == -1) {
perror("Error setting extended attribute");
close(fd);
return 1;
}
close(fd);
return 0;
}
CVSS Source: Linux
CVSS Base score: 7.8
CVSS Vector: (CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H)
CVEID: CVE-2025-68366
DESCRIPTION: In the Linux kernel, the following vulnerability has been resolved:
nbd: defer config unlock in nbd_genl_connect
There is one use-after-free warning when running NBD_CMD_CONNECT and
NBD_CLEAR_SOCK:
nbd_genl_connect
nbd_alloc_and_init_config // config_refs=1
nbd_start_device // config_refs=2
set NBD_RT_HAS_CONFIG_REF open nbd // config_refs=3
recv_work done // config_refs=2
NBD_CLEAR_SOCK // config_refs=1
close nbd // config_refs=0
refcount_inc - uaf
------------[ cut here ]------------
refcount_t: addition on 0; use-after-free.
WARNING: CPU: 24 PID: 1014 at lib/refcount.c:25 refcount_warn_saturate+0x12e/0x290
nbd_genl_connect+0x16d0/0x1ab0
genl_family_rcv_msg_doit+0x1f3/0x310
genl_rcv_msg+0x44a/0x790
The issue can be easily reproduced by adding a small delay before
refcount_inc(&nbd-config_refs) in nbd_genl_connect():
mutex_unlock(&nbd-config_lock);
if (!ret) {
set_bit(NBD_RT_HAS_CONFIG_REF, &config-runtime_flags);
+ printk("before sleep\n");
+ mdelay(5 * 1000);
+ printk("after sleep\n");
refcount_inc(&nbd-config_refs);
nbd_connect_reply(info, nbd-index);
}
CVSS Source: Red Hat
CVSS Base score: 7.1
CVSS Vector: (CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H)
CVEID: CVE-2025-68724
DESCRIPTION: In the Linux kernel, the following vulnerability has been resolved:
crypto: asymmetric_keys - prevent overflow in asymmetric_key_generate_id
Use check_add_overflow() to guard against potential integer overflows
when adding the binary blob lengths and the size of an asymmetric_key_id
structure and return ERR_PTR(-EOVERFLOW) accordingly. This prevents a
possible buffer overflow when copying data from potentially malicious
X.509 certificate fields that can be arbitrarily large, such as ASN.1
INTEGER serial numbers, issuer names, etc.
CVSS Source: Linux
CVSS Base score: 7.8
CVSS Vector: (CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H)
CVEID: CVE-2025-71089
DESCRIPTION: In the Linux kernel, the following vulnerability has been resolved:
iommu: disable SVA when CONFIG_X86 is set
Patch series "Fix stale IOTLB entries for kernel address space", v7.
This proposes a fix for a security vulnerability related to IOMMU Shared
Virtual Addressing (SVA). In an SVA context, an IOMMU can cache kernel
page table entries. When a kernel page table page is freed and
reallocated for another purpose, the IOMMU might still hold stale,
incorrect entries. This can be exploited to cause a use-after-free or
write-after-free condition, potentially leading to privilege escalation or
data corruption.
This solution introduces a deferred freeing mechanism for kernel page
table pages, which provides a safe window to notify the IOMMU to
invalidate its caches before the page is reused.
This patch (of 8):
In the IOMMU Shared Virtual Addressing (SVA) context, the IOMMU hardware
shares and walks the CPU's page tables. The x86 architecture maps the
kernel's virtual address space into the upper portion of every process's
page table. Consequently, in an SVA context, the IOMMU hardware can walk
and cache kernel page table entries.
The Linux kernel currently lacks a notification mechanism for kernel page
table changes, specifically when page table pages are freed and reused.
The IOMMU driver is only notified of changes to user virtual address
mappings. This can cause the IOMMU's internal caches to retain stale
entries for kernel VA.
Use-After-Free (UAF) and Write-After-Free (WAF) conditions arise when
kernel page table pages are freed and later reallocated. The IOMMU could
misinterpret the new data as valid page table entries. The IOMMU might
then walk into attacker-controlled memory, leading to arbitrary physical
memory DMA access or privilege escalation. This is also a
Write-After-Free issue, as the IOMMU will potentially continue to write
Accessed and Dirty bits to the freed memory while attempting to walk the
stale page tables.
Currently, SVA contexts are unprivileged and cannot access kernel
mappings. However, the IOMMU will still walk kernel-only page tables all
the way down to the leaf entries, where it realizes the mapping is for the
kernel and errors out. This means the IOMMU still caches these
intermediate page table entries, making the described vulnerability a real
concern.
Disable SVA on x86 architecture until the IOMMU can receive notification
to flush the paging cache before freeing the CPU kernel page table pages.
CVSS Source: NVD
CVSS Base score: 7.8
CVSS Vector: (CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H)
CVEID: CVE-2026-23392
DESCRIPTION: In the Linux kernel, the following vulnerability has been resolved:
netfilter: nf_tables: release flowtable after rcu grace period on error
Call synchronize_rcu() after unregistering the hooks from error path,
since a hook that already refers to this flowtable can be already
registered, exposing this flowtable to packet path and nfnetlink_hook
control plane.
This error path is rare, it should only happen by reaching the maximum
number hooks or by failing to set up to hardware offload, just call
synchronize_rcu().
There is a check for already used device hooks by different flowtable
that could result in EEXIST at this late stage. The hook parser can be
updated to perform this check earlier to this error path really becomes
rarely exercised.
Uncovered by KASAN reported as use-after-free from nfnetlink_hook path
when dumping hooks.
CWE: CWE-416: Use After Free
CVSS Source: Linux
CVSS Base score: 7.8
CVSS Vector: (CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H)
CVEID: CVE-2026-23455
DESCRIPTION: In the Linux kernel, the following vulnerability has been resolved:
netfilter: nf_conntrack_h323: check for zero length in DecodeQ931()
In DecodeQ931(), the UserUserIE code path reads a 16-bit length from
the packet, then decrements it by 1 to skip the protocol discriminator
byte before passing it to DecodeH323_UserInformation(). If the encoded
length is 0, the decrement wraps to -1, which is then passed as a
large value to the decoder, leading to an out-of-bounds read.
Add a check to ensure len is positive after the decrement.
CWE: CWE-125: Out-of-bounds Read
CVSS Source: Linux
CVSS Base score: 9.1
CVSS Vector: (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H)
CVEID: CVE-2026-31684
DESCRIPTION: In the Linux kernel, the following vulnerability has been resolved:
net: sched: act_csum: validate nested VLAN headers
tcf_csum_act() walks nested VLAN headers directly from skb-data when an
skb still carries in-payload VLAN tags. The current code reads
vlan-h_vlan_encapsulated_proto and then pulls VLAN_HLEN bytes without
first ensuring that the full VLAN header is present in the linear area.
If only part of an inner VLAN header is linearized, accessing
h_vlan_encapsulated_proto reads past the linear area, and the following
skb_pull(VLAN_HLEN) may violate skb invariants.
Fix this by requiring pskb_may_pull(skb, VLAN_HLEN) before accessing and
pulling each nested VLAN header. If the header still is not fully
available, drop the packet through the existing error path.
CVSS Source: NVD
CVSS Base score: 5.5
CVSS Vector: (CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H)
CVEID: CVE-2026-31685
DESCRIPTION: In the Linux kernel, the following vulnerability has been resolved:
netfilter: ip6t_eui64: reject invalid MAC header for all packets
`eui64_mt6()` derives a modified EUI-64 from the Ethernet source address
and compares it with the low 64 bits of the IPv6 source address.
The existing guard only rejects an invalid MAC header when
`par-fragoff != 0`. For packets with `par-fragoff == 0`, `eui64_mt6()`
can still reach `eth_hdr(skb)` even when the MAC header is not valid.
Fix this by removing the `par-fragoff != 0` condition so that packets
with an invalid MAC header are rejected before accessing `eth_hdr(skb)`.
CVSS Source: Linux
CVSS Base score: 9.4
CVSS Vector: (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:H)
CVEID: CVE-2026-43027
DESCRIPTION: In the Linux kernel, the following vulnerability has been resolved:
netfilter: nf_conntrack_helper: pass helper to expect cleanup
nf_conntrack_helper_unregister() calls nf_ct_expect_iterate_destroy()
to remove expectations belonging to the helper being unregistered.
However, it passes NULL instead of the helper pointer as the data
argument, so expect_iter_me() never matches any expectation and all
of them survive the cleanup.
After unregister returns, nfnl_cthelper_del() frees the helper
object immediately. Subsequent expectation dumps or packet-driven
init_conntrack() calls then dereference the freed exp-helper,
causing a use-after-free.
Pass the actual helper pointer so expectations referencing it are
properly destroyed before the helper object is freed.
BUG: KASAN: slab-use-after-free in string+0x38f/0x430
Read of size 1 at addr ffff888003b14d20 by task poc/103
Call Trace:
string+0x38f/0x430
vsnprintf+0x3cc/0x1170
seq_printf+0x17a/0x240
exp_seq_show+0x2e5/0x560
seq_read_iter+0x419/0x1280
proc_reg_read+0x1ac/0x270
vfs_read+0x179/0x930
ksys_read+0xef/0x1c0
Freed by task 103:
The buggy address is located 32 bytes inside of
freed 192-byte region [ffff888003b14d00, ffff888003b14dc0)
CWE: CWE-416: Use After Free
CVSS Source: NVD
CVSS Base score: 7.8
CVSS Vector: (CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H)
CVEID: CVE-2026-43190
DESCRIPTION: In the Linux kernel, the following vulnerability has been resolved:
netfilter: xt_tcpmss: check remaining length before reading optlen
Quoting reporter:
In net/netfilter/xt_tcpmss.c (lines 53-68), the TCP option parser reads
op[i+1] directly without validating the remaining option length.
If the last byte of the option field is not EOL/NOP (0/1), the code attempts
to index op[i+1]. In the case where i + 1 == optlen, this causes an
out-of-bounds read, accessing memory past the optlen boundary
(either reading beyond the stack buffer _opt or the
following payload).
CWE: CWE-125: Out-of-bounds Read
CVSS Source: Linux
CVSS Base score: 8.2
CVSS Vector: (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:H)
CVEID: CVE-2026-43303
DESCRIPTION: In the Linux kernel, the following vulnerability has been resolved:
mm/page_alloc: clear page-private in free_pages_prepare()
Several subsystems (slub, shmem, ttm, etc.) use page-private but don't
clear it before freeing pages. When these pages are later allocated as
high-order pages and split via split_page(), tail pages retain stale
page-private values.
This causes a use-after-free in the swap subsystem. The swap code uses
page-private to track swap count continuations, assuming freshly
allocated pages have page-private == 0. When stale values are present,
swap_count_continued() incorrectly assumes the continuation list is valid
and iterates over uninitialized page-lru containing LIST_POISON values,
causing a crash:
KASAN: maybe wild-memory-access in range [0xdead000000000100-0xdead000000000107]
RIP: 0010:__do_sys_swapoff+0x1151/0x1860
Fix this by clearing page-private in free_pages_prepare(), ensuring all
freed pages have clean state regardless of previous use.
CWE: CWE-416: Use After Free
CVSS Source: Linux
CVSS Base score: 7.8
CVSS Vector: (CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H)
CVEID: CVE-2026-23216
DESCRIPTION: In the Linux kernel, the following vulnerability has been resolved:
scsi: target: iscsi: Fix use-after-free in iscsit_dec_conn_usage_count()
In iscsit_dec_conn_usage_count(), the function calls complete() while
holding the conn-conn_usage_lock. As soon as complete() is invoked, the
waiter (such as iscsit_close_connection()) may wake up and proceed to free
the iscsit_conn structure.
If the waiter frees the memory before the current thread reaches
spin_unlock_bh(), it results in a KASAN slab-use-after-free as the function
attempts to release a lock within the already-freed connection structure.
Fix this by releasing the spinlock before calling complete().
CWE: CWE-416: Use After Free
CVSS Source: NVD
CVSS Base score: 7.8
CVSS Vector: (CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H)
CVEID: CVE-2026-31419
DESCRIPTION: In the Linux kernel, the following vulnerability has been resolved:
net: bonding: fix use-after-free in bond_xmit_broadcast()
bond_xmit_broadcast() reuses the original skb for the last slave
(determined by bond_is_last_slave()) and clones it for others.
Concurrent slave enslave/release can mutate the slave list during
RCU-protected iteration, changing which slave is "last" mid-loop.
This causes the original skb to be double-consumed (double-freed).
Replace the racy bond_is_last_slave() check with a simple index
comparison (i + 1 == slaves_count) against the pre-snapshot slave
count taken via READ_ONCE() before the loop. This preserves the
zero-copy optimization for the last slave while making the "last"
determination stable against concurrent list mutations.
The UAF can trigger the following crash:
==================================================================
BUG: KASAN: slab-use-after-free in skb_clone
Read of size 8 at addr ffff888100ef8d40 by task exploit/147
CPU: 1 UID: 0 PID: 147 Comm: exploit Not tainted 7.0.0-rc3+ #4 PREEMPTLAZY
Call Trace:
TASK
dump_stack_lvl (lib/dump_stack.c:123)
print_report (mm/kasan/report.c:379 mm/kasan/report.c:482)
kasan_report (mm/kasan/report.c:597)
skb_clone (include/linux/skbuff.h:1724 include/linux/skbuff.h:1792 include/linux/skbuff.h:3396 net/core/skbuff.c:2108)
bond_xmit_broadcast (drivers/net/bonding/bond_main.c:5334)
bond_start_xmit (drivers/net/bonding/bond_main.c:5567 drivers/net/bonding/bond_main.c:5593)
dev_hard_start_xmit (include/linux/netdevice.h:5325 include/linux/netdevice.h:5334 net/core/dev.c:3871 net/core/dev.c:3887)
__dev_queue_xmit (include/linux/netdevice.h:3601 net/core/dev.c:4838)
ip6_finish_output2 (include/net/neighbour.h:540 include/net/neighbour.h:554 net/ipv6/ip6_output.c:136)
ip6_finish_output (net/ipv6/ip6_output.c:208 net/ipv6/ip6_output.c:219)
ip6_output (net/ipv6/ip6_output.c:250)
ip6_send_skb (net/ipv6/ip6_output.c:1985)
udp_v6_send_skb (net/ipv6/udp.c:1442)
udpv6_sendmsg (net/ipv6/udp.c:1733)
__sys_sendto (net/socket.c:730 net/socket.c:742 net/socket.c:2206)
__x64_sys_sendto (net/socket.c:2209)
do_syscall_64 (arch/x86/entry/syscall_64.c:63 arch/x86/entry/syscall_64.c:94)
entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130)
/TASK
Allocated by task 147:
Freed by task 147:
The buggy address belongs to the object at ffff888100ef8c80
which belongs to the cache skbuff_head_cache of size 224
The buggy address is located 192 bytes inside of
freed 224-byte region [ffff888100ef8c80, ffff888100ef8d60)
Memory state around the buggy address:
ffff888100ef8c00: fb fb fb fb fc fc fc fc fc fc fc fc fc fc fc fc
ffff888100ef8c80: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff888100ef8d00: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc
^
ffff888100ef8d80: fc fc fc fc fc fc fc fc fa fb fb fb fb fb fb fb
ffff888100ef8e00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================
CWE: CWE-416: Use After Free
CVSS Source: Linux
CVSS Base score: 7.8
CVSS Vector: (CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H)
CVEID: CVE-2026-31508
DESCRIPTION: In the Linux kernel, the following vulnerability has been resolved:
net: openvswitch: Avoid releasing netdev before teardown completes
The patch cited in the Fixes tag below changed the teardown code for
OVS ports to no longer unconditionally take the RTNL. After this change,
the netdev_destroy() callback can proceed immediately to the call_rcu()
invocation if the IFF_OVS_DATAPATH flag is already cleared on the
netdev.
The ovs_netdev_detach_dev() function clears the flag before completing
the unregistration, and if it gets preempted after clearing the flag (as
can happen on an -rt kernel), netdev_destroy() can complete and the
device can be freed before the unregistration completes. This leads to a
splat like:
[ 998.393867] Oops: general protection fault, probably for non-canonical address 0xff00000001000239: 0000 [#1] SMP PTI
[ 998.393877] CPU: 42 UID: 0 PID: 55177 Comm: ip Kdump: loaded Not tainted 6.12.0-211.1.1.el10_2.x86_64+rt #1 PREEMPT_RT
[ 998.393886] Hardware name: Dell Inc. PowerEdge R740/0JMK61, BIOS 2.24.0 03/27/2025
[ 998.393889] RIP: 0010:dev_set_promiscuity+0x8d/0xa0
[ 998.393901] Code: 00 00 75 d8 48 8b 53 08 48 83 ba b0 02 00 00 00 75 ca 48 83 c4 08 5b c3 cc cc cc cc 48 83 bf 48 09 00 00 00 75 91 48 8b 47 08 48 83 b8 b0 02 00 00 00 74 97 eb 81 0f 1f 80 00 00 00 00 90 90 90
[ 998.393906] RSP: 0018:ffffce5864a5f6a0 EFLAGS: 00010246
[ 998.393912] RAX: ff00000000ffff89 RBX: ffff894d0adf5a05 RCX: 0000000000000000
[ 998.393917] RDX: 0000000000000000 RSI: 00000000ffffffff RDI: ffff894d0adf5a05
[ 998.393921] RBP: ffff894d19252000 R08: ffff894d19252000 R09: 0000000000000000
[ 998.393924] R10: ffff894d19252000 R11: ffff894d192521b8 R12: 0000000000000006
[ 998.393927] R13: ffffce5864a5f738 R14: 00000000ffffffe2 R15: 0000000000000000
[ 998.393931] FS: 00007fad61971800(0000) GS:ffff894cc0140000(0000) knlGS:0000000000000000
[ 998.393936] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 998.393940] CR2: 000055df0a2a6e40 CR3: 000000011c7fe003 CR4: 00000000007726f0
[ 998.393944] PKRU: 55555554
[ 998.393946] Call Trace:
[ 998.393949] TASK
[ 998.393952] ? show_trace_log_lvl+0x1b0/0x2f0
[ 998.393961] ? show_trace_log_lvl+0x1b0/0x2f0
[ 998.393975] ? dp_device_event+0x41/0x80 [openvswitch]
[ 998.394009] ? __die_body.cold+0x8/0x12
[ 998.394016] ? die_addr+0x3c/0x60
[ 998.394027] ? exc_general_protection+0x16d/0x390
[ 998.394042] ? asm_exc_general_protection+0x26/0x30
[ 998.394058] ? dev_set_promiscuity+0x8d/0xa0
[ 998.394066] ? ovs_netdev_detach_dev+0x3a/0x80 [openvswitch]
[ 998.394092] dp_device_event+0x41/0x80 [openvswitch]
[ 998.394102] notifier_call_chain+0x5a/0xd0
[ 998.394106] unregister_netdevice_many_notify+0x51b/0xa60
[ 998.394110] rtnl_dellink+0x169/0x3e0
[ 998.394121] ? rt_mutex_slowlock.constprop.0+0x95/0xd0
[ 998.394125] rtnetlink_rcv_msg+0x142/0x3f0
[ 998.394128] ? avc_has_perm_noaudit+0x69/0xf0
[ 998.394130] ? __pfx_rtnetlink_rcv_msg+0x10/0x10
[ 998.394132] netlink_rcv_skb+0x50/0x100
[ 998.394138] netlink_unicast+0x292/0x3f0
[ 998.394141] netlink_sendmsg+0x21b/0x470
[ 998.394145] ____sys_sendmsg+0x39d/0x3d0
[ 998.394149] ___sys_sendmsg+0x9a/0xe0
[ 998.394156] __sys_sendmsg+0x7a/0xd0
[ 998.394160] do_syscall_64+0x7f/0x170
[ 998.394162] entry_SYSCALL_64_after_hwframe+0x76/0x7e
[ 998.394165] RIP: 0033:0x7fad61bf4724
[ 998.394188] Code: 89 02 b8 ff ff ff ff eb bb 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 f3 0f 1e fa 80 3d c5 e9 0c 00 00 74 13 b8 2e 00 00 00 0f 05 48 3d 00 f0 ff ff 77 54 c3 0f 1f 00 48 83 ec 28 89 54 24 1c 48 89
[ 998.394189] RSP: 002b:00007ffd7e2f7cb8 EFLAGS: 00000202 ORIG_RAX: 000000000000002e
[ 998.394191] RAX: ffffffffffffffda RBX: 0000000000000001 RCX: 00007fad61bf4724
[ 998.394193] RDX: 0000000000000000 RSI: 00007ffd7e2f7d20 RDI: 0000000000000003
[ 998.394194] RBP: 00007ffd7e2f7d90 R08: 0000000000000010 R09: 000000000000003f
[ 998.394195] R10: 000055df11558010 R11: 0000000000000202 R12: 00007ffd7e2
---truncated---
CVSS Source: Linux
CVSS Base score: 7.8
CVSS Vector: (CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H)
CVEID: CVE-2026-43037
DESCRIPTION: In the Linux kernel, the following vulnerability has been resolved:
ip6_tunnel: clear skb2-cb[] in ip4ip6_err()
Oskar Kjos reported the following problem.
ip4ip6_err() calls icmp_send() on a cloned skb whose cb[] was written
by the IPv6 receive path as struct inet6_skb_parm. icmp_send() passes
IPCB(skb2) to __ip_options_echo(), which interprets that cb[] region
as struct inet_skb_parm (IPv4). The layouts differ: inet6_skb_parm.nhoff
at offset 14 overlaps inet_skb_parm.opt.rr, producing a non-zero rr
value. __ip_options_echo() then reads optlen from attacker-controlled
packet data at sptr[rr+1] and copies that many bytes into dopt-__data,
a fixed 40-byte stack buffer (IP_OPTIONS_DATA_FIXED_SIZE).
To fix this we clear skb2-cb[], as suggested by Oskar Kjos.
Also add minimal IPv4 header validation (version == 4, ihl = 5).
CWE: CWE-787: Out-of-bounds Write
CVSS Source: Linux
CVSS Base score: 9.8
CVSS Vector: (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H)
CVEID: CVE-2026-43056
DESCRIPTION: In the Linux kernel, the following vulnerability has been resolved:
net: mana: fix use-after-free in add_adev() error path
If auxiliary_device_add() fails, add_adev() jumps to add_fail and calls
auxiliary_device_uninit(adev).
The auxiliary device has its release callback set to adev_release(),
which frees the containing struct mana_adev. Since adev is embedded in
struct mana_adev, the subsequent fall-through to init_fail and access
to adev-id may result in a use-after-free.
Fix this by saving the allocated auxiliary device id in a local
variable before calling auxiliary_device_add(), and use that saved id
in the cleanup path after auxiliary_device_uninit().
CWE: CWE-416: Use After Free
CVSS Source: Linux
CVSS Base score: 7.8
CVSS Vector: (CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H)
CVEID: CVE-2026-43116
DESCRIPTION: In the Linux kernel, the following vulnerability has been resolved:
netfilter: ctnetlink: ensure safe access to master conntrack
Holding reference on the expectation is not sufficient, the master
conntrack object can just go away, making exp-master invalid.
To access exp-master safely:
- Grab the nf_conntrack_expect_lock, this gets serialized with
clean_from_lists() which also holds this lock when the master
conntrack goes away.
- Hold reference on master conntrack via nf_conntrack_find_get().
Not so easy since the master tuple to look up for the master conntrack
is not available in the existing problematic paths.
This patch goes for extending the nf_conntrack_expect_lock section
to address this issue for simplicity, in the cases that are described
below this is just slightly extending the lock section.
The add expectation command already holds a reference to the master
conntrack from ctnetlink_create_expect().
However, the delete expectation command needs to grab the spinlock
before looking up for the expectation. Expand the existing spinlock
section to address this to cover the expectation lookup. Note that,
the nf_ct_expect_iterate_net() calls already grabs the spinlock while
iterating over the expectation table, which is correct.
The get expectation command needs to grab the spinlock to ensure master
conntrack does not go away. This also expands the existing spinlock
section to cover the expectation lookup too. I needed to move the
netlink skb allocation out of the spinlock to keep it GFP_KERNEL.
For the expectation events, the IPEXP_DESTROY event is already delivered
under the spinlock, just move the delivery of IPEXP_NEW under the
spinlock too because the master conntrack event cache is reached through
exp-master.
While at it, add lockdep notations to help identify what codepaths need
to grab the spinlock.
CWE: CWE-362: Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')
CVSS Source: Linux
CVSS Base score: 7.8
CVSS Vector: (CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H)
CVEID: CVE-2026-43125
DESCRIPTION: In the Linux kernel, the following vulnerability has been resolved:
dlm: validate length in dlm_search_rsb_tree
The len parameter in dlm_dump_rsb_name() is not validated and comes
from network messages. When it exceeds DLM_RESNAME_MAXLEN, it can
cause out-of-bounds write in dlm_search_rsb_tree().
Add length validation to prevent potential buffer overflow.
CWE: CWE-787: Out-of-bounds Write
CVSS Source: Linux
CVSS Base score: 9.8
CVSS Vector: (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H)
CVEID: CVE-2026-43501
DESCRIPTION: In the Linux kernel, the following vulnerability has been resolved:
ipv6: rpl: reserve mac_len headroom when recompressed SRH grows
ipv6_rpl_srh_rcv() decompresses an RFC 6554 Source Routing Header, swaps
the next segment into ipv6_hdr-daddr, recompresses, then pulls the old
header and pushes the new one plus the IPv6 header back. The
recompressed header can be larger than the received one when the swap
reduces the common-prefix length the segments share with daddr (CmprI=0,
CmprE0, seg[0][0] != daddr[0] gives the maximum +8 bytes).
pskb_expand_head() was gated on segments_left == 0, so on earlier
segments the push consumed unchecked headroom. Once skb_push() leaves
fewer than skb-mac_len bytes in front of data,
skb_mac_header_rebuild()'s call to:
skb_set_mac_header(skb, -skb-mac_len);
will store (data - head) - mac_len into the u16 mac_header field, which
wraps to ~65530, and the following memmove() writes mac_len bytes ~64KiB
past skb-head.
A single AF_INET6/SOCK_RAW/IPV6_HDRINCL packet over lo with a two
segment type-3 SRH (CmprI=0, CmprE=15) reaches headroom 8 after one
pass; KASAN reports a 14-byte OOB write in ipv6_rthdr_rcv.
Fix this by expanding the head whenever the remaining room is less than
the push size plus mac_len, and request that much extra so the rebuilt
MAC header fits afterwards.
CWE: CWE-787: Out-of-bounds Write
CVSS Source: Linux
CVSS Base score: 9.8
CVSS Vector: (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H)
CVEID: CVE-2025-68214
DESCRIPTION: In the Linux kernel, the following vulnerability has been resolved:
timers: Fix NULL function pointer race in timer_shutdown_sync()
There is a race condition between timer_shutdown_sync() and timer
expiration that can lead to hitting a WARN_ON in expire_timers().
The issue occurs when timer_shutdown_sync() clears the timer function
to NULL while the timer is still running on another CPU. The race
scenario looks like this:
CPU0 CPU1
SOFTIRQ
lock_timer_base()
expire_timers()
base-running_timer = timer;
unlock_timer_base()
[call_timer_fn enter]
mod_timer()
...
timer_shutdown_sync()
lock_timer_base()
// For now, will not detach the timer but only clear its function to NULL
if (base-running_timer != timer)
ret = detach_if_pending(timer, base, true);
if (shutdown)
timer-function = NULL;
unlock_timer_base()
[call_timer_fn exit]
lock_timer_base()
base-running_timer = NULL;
unlock_timer_base()
...
// Now timer is pending while its function set to NULL.
// next timer trigger
SOFTIRQ
expire_timers()
WARN_ON_ONCE(!fn) // hit
...
lock_timer_base()
// Now timer will detach
if (base-running_timer != timer)
ret = detach_if_pending(timer, base, true);
if (shutdown)
timer-function = NULL;
unlock_timer_base()
The problem is that timer_shutdown_sync() clears the timer function
regardless of whether the timer is currently running. This can leave a
pending timer with a NULL function pointer, which triggers the
WARN_ON_ONCE(!fn) check in expire_timers().
Fix this by only clearing the timer function when actually detaching the
timer. If the timer is running, leave the function pointer intact, which is
safe because the timer will be properly detached when it finishes running.
CWE: CWE-362: Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')
CVSS Source: NVD
CVSS Base score: 4.7
CVSS Vector: (CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H)
CVEID: CVE-2026-53264
DESCRIPTION: In the Linux kernel, the following vulnerability has been resolved:
net/sched: act_api: use RCU with deferred freeing for action lifecycle
When NEWTFILTER and DELFILTER are run concurrently it is possible to create a
race with an associated action.
Let's illustrate with CPU0 running NEWTFILTER and CPU1 running DELFILTER:
0: mutex_lock() -- holds the idr lock
0: rcu_read_lock()
0: p = idr_find(idr, index) -- action p is valid (RCU protects IDR)
0: mutex_unlock() -- releases the idr lock
1: refcount_dec_and_mutex_lock() -- refcnt 1-0, mutex held
1: idr_remove(idr, index) -- Action removed from IDR
1: mutex_unlock() -- mutex released allowing us to delete the action
1: tcf_action_cleanup(p); kfree(p) -- Kfrees p immediately, no deferral
0: refcount_inc_not_zero(&p-tcfa_refcnt) -- ouch, UAF p points to freed memory
This patch fixes the race condition between NEWTFILTER and DELFILTER by
adding struct rcu_head to tc_action used in the deferral and introducing a
call_rcu() in the delete path to defer the final kfree().
Note: this is a revert of commit d7fb60b9cafb ("net_sched: get rid of tcfa_rcu")
but also modernization/simplification to directly use kfree_rcu().
Let's illustrate the new restored code path:
0: rcu_read_lock()
1: refcount_dec_and_mutex_lock() -- refcnt 1-0, mutex held
1: idr_remove(idr, index)
1: mutex_unlock()
1: call_rcu(&p-tcfa_rcu, tcf_action_rcu_free) -- defer kfree after grace period
0: p = idr_find(idr, index)
0: refcount_inc_not_zero(&p-tcfa_refcnt) -- fails, refcnt already 0
1: rcu_read_unlock() -- release so freeing can run after grace period
After CPU1 calls idr_remove(), the object is no longer reachable through the IDR.
CPU0's subsequent idr_find() will return NULL, and even if it still held a
stale pointer, the immediate kfree() is now deferred until after the RCU grace
period, so no UAF can occur.
CWE: CWE-416: Use After Free
CVSS Source: Linux
CVSS Base score: 7.8
CVSS Vector: (CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H)
CVEID: CVE-2026-52923
DESCRIPTION: In the Linux kernel, the following vulnerability has been resolved:
ipc: limit next_id allocation to the valid ID range
The checkpoint/restore sysctl path can request the next SysV IPC id
through ids-next_id. ipc_idr_alloc() currently forwards that request to
idr_alloc() with an open-ended upper bound.
If the valid tail of the SysV IPC id space is full, the allocation can
spill beyond ipc_mni. The returned SysV IPC id still uses the normal
index encoding, so later lookup and removal can target the wrong slot.
This leaves the real IDR entry behind and breaks the IDR state for the
object.
The bug is in ipc_idr_alloc() in the checkpoint/restore path.
1. ids-next_id is passed to:
idr_alloc(&ids-ipcs_idr, new, ipcid_to_idx(next_id), 0, ...)
2. The zero upper bound makes the allocation effectively open-ended.
Once the valid SysV IPC tail is occupied, idr_alloc() can spill past
ipc_mni and allocate an entry beyond the valid IPC id range.
3. The new object id is still encoded with the narrower SysV IPC index
width:
new-id = (new-seq ipcmni_seq_shift()) + idx
4. Later removal goes through ipc_rmid(), which uses:
ipcid_to_idx(ipcp-id)
That truncates the real IDR index. An object actually stored at a
high index can then be removed as if it lived at a low in-range
index.
5. For shared memory, shm_destroy() frees the current object anyway, but
the real high IDR slot is left behind as a dangling pointer.
6. A subsequent walk of /proc/sysvipc/shm reaches the stale IDR entry
and dereferences freed memory.
Prevent this by bounding the requested allocation to ipc_mni so the
checkpoint/restore path fails once the valid range is exhausted.
CWE: CWE-401: Missing Release of Memory after Effective Lifetime
CVSS Source: Linux
CVSS Base score: 7.8
CVSS Vector: (CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H)
CVEID: CVE-2026-64530
DESCRIPTION: In the Linux kernel, the following vulnerability has been resolved:
net/sched: cls_api: Handle TC_ACT_CONSUMED in tcf_qevent_handle
tcf_classify() can return TC_ACT_CONSUMED while the skb is held by the
defragmentation engine (e.g. act_ct on out-of-order fragments). When
that happens the skb is no longer owned by the caller and must not be
touched again.
tcf_qevent_handle() did not handle TC_ACT_CONSUMED: it fell through the
switch and returned the skb to the caller as if classification had
passed. The only qdisc that wires up qevents today is RED, via three call sites
(qe_mark on RED_PROB_MARK/HARD_MARK, qe_early_drop on congestion_drop)
red_enqueue() was continuing to operate on an skb it no longer owns in this
case -- enqueueing it, dropping it, or updating statistics. Resulting in a UAF.
tc qdisc add dev eth0 root handle 1: red ... qevent early_drop block 10
tc filter add block 10 ... action ct
(with ct defrag enabled and traffic that produces out-of-order
fragments, e.g. a fragmented UDP stream)
Handle TC_ACT_CONSUMED in tcf_qevent_handle() the same way the ingress
and egress fast paths do: treat it as stolen and return NULL without
touching the skb. Unlike the TC_ACT_STOLEN case, the skb must not be
dropped/freed here, as it is no longer owned by us.
CVSS Source: Linux
CVSS Base score: 9.8
CVSS Vector: (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H)
CVEID: CVE-2025-39766
DESCRIPTION: In the Linux kernel, the following vulnerability has been resolved:
net/sched: Make cake_enqueue return NET_XMIT_CN when past buffer_limit
The following setup can trigger a WARNING in htb_activate due to
the condition: !cl-leaf.q-q.qlen
tc qdisc del dev lo root
tc qdisc add dev lo root handle 1: htb default 1
tc class add dev lo parent 1: classid 1:1 \
htb rate 64bit
tc qdisc add dev lo parent 1:1 handle f: \
cake memlimit 1b
ping -I lo -f -c1 -s64 -W0.001 127.0.0.1
This is because the low memlimit leads to a low buffer_limit, which
causes packet dropping. However, cake_enqueue still returns
NET_XMIT_SUCCESS, causing htb_enqueue to call htb_activate with an
empty child qdisc. We should return NET_XMIT_CN when packets are
dropped from the same tin and flow.
I do not believe return value of NET_XMIT_CN is necessary for packet
drops in the case of ack filtering, as that is meant to optimize
performance, not to signal congestion.
CVSS Source: NVD
CVSS Base score: 7.8
CVSS Vector: (CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H)
CVEID: CVE-2026-23204
DESCRIPTION: In the Linux kernel, the following vulnerability has been resolved:
net/sched: cls_u32: use skb_header_pointer_careful()
skb_header_pointer() does not fully validate negative @offset values.
Use skb_header_pointer_careful() instead.
GangMin Kim provided a report and a repro fooling u32_classify():
BUG: KASAN: slab-out-of-bounds in u32_classify+0x1180/0x11b0
net/sched/cls_u32.c:221
CWE: CWE-125: Out-of-bounds Read
CVSS Source: NVD
CVSS Base score: 7.1
CVSS Vector: (CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H)
CVEID: CVE-2026-23270
DESCRIPTION: In the Linux kernel, the following vulnerability has been resolved:
net/sched: Only allow act_ct to bind to clsact/ingress qdiscs and shared blocks
As Paolo said earlier [1]:
"Since the blamed commit below, classify can return TC_ACT_CONSUMED while
the current skb being held by the defragmentation engine. As reported by
GangMin Kim, if such packet is that may cause a UaF when the defrag engine
later on tries to tuch again such packet."
act_ct was never meant to be used in the egress path, however some users
are attaching it to egress today [2]. Attempting to reach a middle
ground, we noticed that, while most qdiscs are not handling
TC_ACT_CONSUMED, clsact/ingress qdiscs are. With that in mind, we
address the issue by only allowing act_ct to bind to clsact/ingress
qdiscs and shared blocks. That way it's still possible to attach act_ct to
egress (albeit only with clsact).
[1] https://lore.kernel.org/netdev/674b8cbfc385c6f37fb29a1de08d8fe5c2b0fbee…
[2] https://lore.kernel.org/netdev/cc6bfb4a-4a2b-42d8-b9ce-7ef6644fb22b@ovn…
CWE: CWE-416: Use After Free
CVSS Source: Linux
CVSS Base score: 7.8
CVSS Vector: (CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H)
CVEID: CVE-2026-31532
DESCRIPTION: In the Linux kernel, the following vulnerability has been resolved:
can: raw: fix ro-uniq use-after-free in raw_rcv()
raw_release() unregisters raw CAN receive filters via can_rx_unregister(),
but receiver deletion is deferred with call_rcu(). This leaves a window
where raw_rcv() may still be running in an RCU read-side critical section
after raw_release() frees ro-uniq, leading to a use-after-free of the
percpu uniq storage.
Move free_percpu(ro-uniq) out of raw_release() and into a raw-specific
socket destructor. can_rx_unregister() takes an extra reference to the
socket and only drops it from the RCU callback, so freeing uniq from
sk_destruct ensures the percpu area is not released until the relevant
callbacks have drained.
[mkl: applied manually]
CWE: CWE-416: Use After Free
CVSS Source: NVD
CVSS Base score: 7.8
CVSS Vector: (CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H)
CVEID: CVE-2026-31607
DESCRIPTION: In the Linux kernel, the following vulnerability has been resolved:
usbip: validate number_of_packets in usbip_pack_ret_submit()
When a USB/IP client receives a RET_SUBMIT response,
usbip_pack_ret_submit() unconditionally overwrites
urb-number_of_packets from the network PDU. This value is
subsequently used as the loop bound in usbip_recv_iso() and
usbip_pad_iso() to iterate over urb-iso_frame_desc[], a flexible
array whose size was fixed at URB allocation time based on the
*original* number_of_packets from the CMD_SUBMIT.
A malicious USB/IP server can set number_of_packets in the response
to a value larger than what was originally submitted, causing a heap
out-of-bounds write when usbip_recv_iso() writes to
urb-iso_frame_desc[i] beyond the allocated region.
KASAN confirmed this with kernel 7.0.0-rc5:
BUG: KASAN: slab-out-of-bounds in usbip_recv_iso+0x46a/0x640
Write of size 4 at addr ffff888106351d40 by task vhci_rx/69
The buggy address is located 0 bytes to the right of
allocated 320-byte region [ffff888106351c00, ffff888106351d40)
The server side (stub_rx.c) and gadget side (vudc_rx.c) already
validate number_of_packets in the CMD_SUBMIT path since commits
c6688ef9f297 ("usbip: fix stub_rx: harden CMD_SUBMIT path to handle
malicious input") and b78d830f0049 ("usbip: fix vudc_rx: harden
CMD_SUBMIT path to handle malicious input"). The server side validates
against USBIP_MAX_ISO_PACKETS because no URB exists yet at that point.
On the client side we have the original URB, so we can use the tighter
bound: the response must not exceed the original number_of_packets.
This mirrors the existing validation of actual_length against
transfer_buffer_length in usbip_recv_xbuff(), which checks the
response value against the original allocation size.
Kelvin Mbogo's series ("usb: usbip: fix integer overflow in
usbip_recv_iso()", v2) hardens the receive-side functions themselves;
this patch complements that work by catching the bad value at its
source -- in usbip_pack_ret_submit() before the overwrite -- and
using the tighter per-URB allocation bound rather than the global
USBIP_MAX_ISO_PACKETS limit.
Fix this by checking rpdu-number_of_packets against
urb-number_of_packets in usbip_pack_ret_submit() before the
overwrite. On violation, clamp to zero so that usbip_recv_iso() and
usbip_pad_iso() safely return early.
CWE: CWE-787: Out-of-bounds Write
CVSS Source: Linux
CVSS Base score: 9.8
CVSS Vector: (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H)
CVEID: CVE-2026-43163
DESCRIPTION: In the Linux kernel, the following vulnerability has been resolved:
md/bitmap: fix GPF in write_page caused by resize race
A General Protection Fault occurs in write_page() during array resize:
RIP: 0010:write_page+0x22b/0x3c0 [md_mod]
This is a use-after-free race between bitmap_daemon_work() and
__bitmap_resize(). The daemon iterates over `bitmap-storage.filemap`
without locking, while the resize path frees that storage via
md_bitmap_file_unmap(). `quiesce()` does not stop the md thread,
allowing concurrent access to freed pages.
Fix by holding `mddev-bitmap_info.mutex` during the bitmap update.
CWE: CWE-362: Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')
CVSS Source: NVD
CVSS Base score: 4.7
CVSS Vector: (CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H)
CVEID: CVE-2026-43284
DESCRIPTION: In the Linux kernel, the following vulnerability has been resolved:
xfrm: esp: avoid in-place decrypt on shared skb frags
MSG_SPLICE_PAGES can attach pages from a pipe directly to an skb. TCP
marks such skbs with SKBFL_SHARED_FRAG after skb_splice_from_iter(),
so later paths that may modify packet data can first make a private
copy. The IPv4/IPv6 datagram append paths did not set this flag when
splicing pages into UDP skbs.
That leaves an ESP-in-UDP packet made from shared pipe pages looking
like an ordinary uncloned nonlinear skb. ESP input then takes the no-COW
fast path for uncloned skbs without a frag_list and decrypts in place
over data that is not owned privately by the skb.
Mark IPv4/IPv6 datagram splice frags with SKBFL_SHARED_FRAG, matching
TCP. Also make ESP input fall back to skb_cow_data() when the flag is
present, so ESP does not decrypt externally backed frags in place.
Private nonlinear skb frags still use the existing fast path.
This intentionally does not change ESP output. In esp_output_head(),
the path that appends the ESP trailer to existing skb tailroom without
calling skb_cow_data() is not reachable for nonlinear skbs:
skb_tailroom() returns zero when skb-data_len is nonzero, while ESP
tailen is positive. Thus ESP output will either use the separate
destination-frag path or fall back to skb_cow_data().
CWE: CWE-123: Write-what-where Condition
CVSS Source: Linux
CVSS Base score: 8.8
CVSS Vector: (CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H)
CVEID: CVE-2026-46300
DESCRIPTION: In the Linux kernel, the following vulnerability has been resolved:
net: skbuff: preserve shared-frag marker during coalescing
skb_try_coalesce() can attach paged frags from @from to @to. If @from
has SKBFL_SHARED_FRAG set, the resulting @to skb can contain the same
externally-owned or page-cache-backed frags, but the shared-frag marker
is currently lost.
That breaks the invariant relied on by later in-place writers. In
particular, ESP input checks skb_has_shared_frag() before deciding
whether an uncloned nonlinear skb can skip skb_cow_data(). If TCP
receive coalescing has moved shared frags into an unmarked skb, ESP can
see skb_has_shared_frag() as false and decrypt in place over page-cache
backed frags.
Propagate SKBFL_SHARED_FRAG when skb_try_coalesce() transfers paged
frags. The tailroom copy path does not need the marker because it copies
bytes into @to's linear data rather than transferring frag descriptors.
CWE: CWE-787: Out-of-bounds Write
CVSS Source: NVD
CVSS Base score: 7.8
CVSS Vector: (CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H)
CVEID: CVE-2026-46333
DESCRIPTION: In the Linux kernel, the following vulnerability has been resolved:
ptrace: slightly saner 'get_dumpable()' logic
The 'dumpability' of a task is fundamentally about the memory image of
the task - the concept comes from whether it can core dump or not - and
makes no sense when you don't have an associated mm.
And almost all users do in fact use it only for the case where the task
has a mm pointer.
But we have one odd special case: ptrace_may_access() uses 'dumpable' to
check various other things entirely independently of the MM (typically
explicitly using flags like PTRACE_MODE_READ_FSCREDS). Including for
threads that no longer have a VM (and maybe never did, like most kernel
threads).
It's not what this flag was designed for, but it is what it is.
The ptrace code does check that the uid/gid matches, so you do have to
be uid-0 to see kernel thread details, but this means that the
traditional "drop capabilities" model doesn't make any difference for
this all.
Make it all make a *bit* more sense by saying that if you don't have a
MM pointer, we'll use a cached "last dumpability" flag if the thread
ever had a MM (it will be zero for kernel threads since it is never
set), and require a proper CAP_SYS_PTRACE capability to override.
CWE: CWE-269: Improper Privilege Management
CVSS Source: Linux
CVSS Base score: 7.1
CVSS Vector: (CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N)
CVEID: CVE-2026-31488
DESCRIPTION: In the Linux kernel, the following vulnerability has been resolved:
drm/amd/display: Do not skip unrelated mode changes in DSC validation
Starting with commit 17ce8a6907f7 ("drm/amd/display: Add dsc pre-validation in
atomic check"), amdgpu resets the CRTC state mode_changed flag to false when
recomputing the DSC configuration results in no timing change for a particular
stream.
However, this is incorrect in scenarios where a change in MST/DSC configuration
happens in the same KMS commit as another (unrelated) mode change. For example,
the integrated panel of a laptop may be configured differently (e.g., HDR
enabled/disabled) depending on whether external screens are attached. In this
case, plugging in external DP-MST screens may result in the mode_changed flag
being dropped incorrectly for the integrated panel if its DSC configuration
did not change during precomputation in pre_validate_dsc().
At this point, however, dm_update_crtc_state() has already created new streams
for CRTCs with DSC-independent mode changes. In turn,
amdgpu_dm_commit_streams() will never release the old stream, resulting in a
memory leak. amdgpu_dm_atomic_commit_tail() will never acquire a reference to
the new stream either, which manifests as a use-after-free when the stream gets
disabled later on:
BUG: KASAN: use-after-free in dc_stream_release+0x25/0x90 [amdgpu]
Write of size 4 at addr ffff88813d836524 by task kworker/9:9/29977
Workqueue: events drm_mode_rmfb_work_fn
Call Trace:
TASK
dump_stack_lvl+0x6e/0xa0
print_address_description.constprop.0+0x88/0x320
? dc_stream_release+0x25/0x90 [amdgpu]
print_report+0xfc/0x1ff
? srso_alias_return_thunk+0x5/0xfbef5
? __virt_addr_valid+0x225/0x4e0
? dc_stream_release+0x25/0x90 [amdgpu]
kasan_report+0xe1/0x180
? dc_stream_release+0x25/0x90 [amdgpu]
kasan_check_range+0x125/0x200
dc_stream_release+0x25/0x90 [amdgpu]
dc_state_destruct+0x14d/0x5c0 [amdgpu]
dc_state_release.part.0+0x4e/0x130 [amdgpu]
dm_atomic_destroy_state+0x3f/0x70 [amdgpu]
drm_atomic_state_default_clear+0x8ee/0xf30
? drm_mode_object_put.part.0+0xb1/0x130
__drm_atomic_state_free+0x15c/0x2d0
atomic_remove_fb+0x67e/0x980
Since there is no reliable way of figuring out whether a CRTC has unrelated
mode changes pending at the time of DSC validation, remember the value of the
mode_changed flag from before the point where a CRTC was marked as potentially
affected by a change in DSC configuration. Reset the mode_changed flag to this
earlier value instead in pre_validate_dsc().
(cherry picked from commit cc7c7121ae082b7b82891baa7280f1ff2608f22b)
CWE: CWE-416: Use After Free
CVSS Source: Linux
CVSS Base score: 7.8
CVSS Vector: (CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H)
CVEID: CVE-2026-43038
DESCRIPTION: In the Linux kernel, the following vulnerability has been resolved:
ipv6: icmp: clear skb2-cb[] in ip6_err_gen_icmpv6_unreach()
Sashiko AI-review observed:
In ip6_err_gen_icmpv6_unreach(), the skb is an outer IPv4 ICMP error packet
where its cb contains an IPv4 inet_skb_parm. When skb is cloned into skb2
and passed to icmp6_send(), it uses IP6CB(skb2).
IP6CB interprets the IPv4 inet_skb_parm as an inet6_skb_parm. The cipso
offset in inet_skb_parm.opt directly overlaps with dsthao in inet6_skb_parm
at offset 18.
If an attacker sends a forged ICMPv4 error with a CIPSO IP option, dsthao
would be a non-zero offset. Inside icmp6_send(), mip6_addr_swap() is called
and uses ipv6_find_tlv(skb, opt-dsthao, IPV6_TLV_HAO).
This would scan the inner, attacker-controlled IPv6 packet starting at that
offset, potentially returning a fake TLV without checking if the remaining
packet length can hold the full 18-byte struct ipv6_destopt_hao.
Could mip6_addr_swap() then perform a 16-byte swap that extends past the end
of the packet data into skb_shared_info?
Should the cb array also be cleared in ip6_err_gen_icmpv6_unreach() and
ip6ip6_err() to prevent this?
This patch implements the first suggestion.
I am not sure if ip6ip6_err() needs to be changed.
A separate patch would be better anyway.
CWE: CWE-843: Access of Resource Using Incompatible Type ('Type Confusion')
CVSS Source: Linux
CVSS Base score: 9.8
CVSS Vector: (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H)
CVEID: CVE-2026-43329
DESCRIPTION: In the Linux kernel, the following vulnerability has been resolved:
netfilter: flowtable: strictly check for maximum number of actions
The maximum number of flowtable hardware offload actions in IPv6 is:
* ethernet mangling (4 payload actions, 2 for each ethernet address)
* SNAT (4 payload actions)
* DNAT (4 payload actions)
* Double VLAN (4 vlan actions, 2 for popping vlan, and 2 for pushing)
for QinQ.
* Redirect (1 action)
Which makes 17, while the maximum is 16. But act_ct supports for tunnels
actions too. Note that payload action operates at 32-bit word level, so
mangling an IPv6 address takes 4 payload actions.
Update flow_action_entry_next() calls to check for the maximum number of
supported actions.
While at it, rise the maximum number of actions per flow from 16 to 24
so this works fine with IPv6 setups.
CWE: CWE-770: Allocation of Resources Without Limits or Throttling
CVSS Source: Linux
CVSS Base score: 7.8
CVSS Vector: (CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H)
CVEID: CVE-2026-46054
DESCRIPTION: In the Linux kernel, the following vulnerability has been resolved:
selinux: fix overlayfs mmap() and mprotect() access checks
The existing SELinux security model for overlayfs is to allow access if
the current task is able to access the top level file (the "user" file)
and the mounter's credentials are sufficient to access the lower
level file (the "backing" file). Unfortunately, the current code does
not properly enforce these access controls for both mmap() and mprotect()
operations on overlayfs filesystems.
This patch makes use of the newly created security_mmap_backing_file()
LSM hook to provide the missing backing file enforcement for mmap()
operations, and leverages the backing file API and new LSM blob to
provide the necessary information to properly enforce the mprotect()
access controls.
CWE: CWE-280: Improper Handling of Insufficient Permissions or Privileges
CVSS Source: Linux
CVSS Base score: 7.1
CVSS Vector: (CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N)
CVEID: CVE-2025-39797
DESCRIPTION: In the Linux kernel, the following vulnerability has been resolved:
xfrm: Duplicate SPI Handling
The issue originates when Strongswan initiates an XFRM_MSG_ALLOCSPI
Netlink message, which triggers the kernel function xfrm_alloc_spi().
This function is expected to ensure uniqueness of the Security Parameter
Index (SPI) for inbound Security Associations (SAs). However, it can
return success even when the requested SPI is already in use, leading
to duplicate SPIs assigned to multiple inbound SAs, differentiated
only by their destination addresses.
This behavior causes inconsistencies during SPI lookups for inbound packets.
Since the lookup may return an arbitrary SA among those with the same SPI,
packet processing can fail, resulting in packet drops.
According to RFC 4301 section 4.4.2 , for inbound processing a unicast SA
is uniquely identified by the SPI and optionally protocol.
Reproducing the Issue Reliably:
To consistently reproduce the problem, restrict the available SPI range in
charon.conf : spi_min = 0x10000000 spi_max = 0x10000002
This limits the system to only 2 usable SPI values.
Next, create more than 2 Child SA. each using unique pair of src/dst address.
As soon as the 3rd Child SA is initiated, it will be assigned a duplicate
SPI, since the SPI pool is already exhausted.
With a narrow SPI range, the issue is consistently reproducible.
With a broader/default range, it becomes rare and unpredictable.
Current implementation:
xfrm_spi_hash() lookup function computes hash using daddr, proto, and family.
So if two SAs have the same SPI but different destination addresses, then
they will:
a. Hash into different buckets
b. Be stored in different linked lists (byspi + h)
c. Not be seen in the same hlist_for_each_entry_rcu() iteration.
As a result, the lookup will result in NULL and kernel allows that Duplicate SPI
Proposed Change:
xfrm_state_lookup_spi_proto() does a truly global search - across all states,
regardless of hash bucket and matches SPI and proto.
CVSS Source: NVD
CVSS Base score: 7.8
CVSS Vector: (CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H)
CVEID: CVE-2026-23002
DESCRIPTION: In the Linux kernel, the following vulnerability has been resolved:
lib/buildid: use __kernel_read() for sleepable context
Prevent a "BUG: unable to handle kernel NULL pointer dereference in
filemap_read_folio".
For the sleepable context, convert freader to use __kernel_read() instead
of direct page cache access via read_cache_folio(). This simplifies the
faultable code path by using the standard kernel file reading interface
which handles all the complexity of reading file data.
At the moment we are not changing the code for non-sleepable context which
uses filemap_get_folio() and only succeeds if the target folios are
already in memory and up-to-date. The reason is to keep the patch simple
and easier to backport to stable kernels.
Syzbot repro does not crash the kernel anymore and the selftests run
successfully.
In the follow up we will make __kernel_read() with IOCB_NOWAIT work for
non-sleepable contexts. In addition, I would like to replace the
secretmem check with a more generic approach and will add fstest for the
buildid code.
CWE: CWE-476: NULL Pointer Dereference
CVSS Source: NVD
CVSS Base score: 5.5
CVSS Vector: (CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H)
CVEID: CVE-2026-64017
DESCRIPTION: In the Linux kernel, the following vulnerability has been resolved:
blk-mq: pop cached request if it is usable
When submitting a bio to blk-mq, if the task should sleep after peeking
a cached request, but before it pops it, the plug flushes and calls
blk_mq_free_plug_rqs, freeing the cached_rqs. This creates a
use-after-free bug. Fix this by popping the cached request before any
possible blocking calls if it is suitable for use.
Popping this request first holds a queue reference, so avoid any
serialization races with queue freezes and can safely proceed with
dispatching that request to the driver. This potentially increases a
timing window from when a driver wants to freeze its queue to when
requests stop being dispatched. That scenario is off the fast path
though, and drivers need to appropriately handle requests during a
freeze request anyway.
The downside is the popped element needs to be individually freed when
we performed a bio plug merge. The cached request would have had to be
freed later anyway, but this patch does it inline with building the plug
list instead of after flushing it.
CVSS Source: Linux
CVSS Base score: 7.8
CVSS Vector: (CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H)
CVEID: CVE-2026-31669
DESCRIPTION: In the Linux kernel, the following vulnerability has been resolved:
mptcp: fix slab-use-after-free in __inet_lookup_established
The ehash table lookups are lockless and rely on
SLAB_TYPESAFE_BY_RCU to guarantee socket memory stability
during RCU read-side critical sections. Both tcp_prot and
tcpv6_prot have their slab caches created with this flag
via proto_register().
However, MPTCP's mptcp_subflow_init() copies tcpv6_prot into
tcpv6_prot_override during inet_init() (fs_initcall, level 5),
before inet6_init() (module_init/device_initcall, level 6) has
called proto_register(&tcpv6_prot). At that point,
tcpv6_prot.slab is still NULL, so tcpv6_prot_override.slab
remains NULL permanently.
This causes MPTCP v6 subflow child sockets to be allocated via
kmalloc (falling into kmalloc-4k) instead of the TCPv6 slab
cache. The kmalloc-4k cache lacks SLAB_TYPESAFE_BY_RCU, so
when these sockets are freed without SOCK_RCU_FREE (which is
cleared for child sockets by design), the memory can be
immediately reused. Concurrent ehash lookups under
rcu_read_lock can then access freed memory, triggering a
slab-use-after-free in __inet_lookup_established.
Fix this by splitting the IPv6-specific initialization out of
mptcp_subflow_init() into a new mptcp_subflow_v6_init(), called
from mptcp_proto_v6_init() before protocol registration. This
ensures tcpv6_prot_override.slab correctly inherits the
SLAB_TYPESAFE_BY_RCU slab cache.
CWE: CWE-416: Use After Free
CVSS Source: Linux
CVSS Base score: 9.8
CVSS Vector: (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H)
CVEID: CVE-2026-43260
DESCRIPTION: In the Linux kernel, the following vulnerability has been resolved:
bnxt_en: Fix RSS context delete logic
We need to free the corresponding RSS context VNIC
in FW everytime an RSS context is deleted in driver.
Commit 667ac333dbb7 added a check to delete the VNIC
in FW only when netif_running() is true to help delete
RSS contexts with interface down.
Having that condition will make the driver leak VNICs
in FW whenever close() happens with active RSS contexts.
On the subsequent open(), as part of RSS context restoration,
we will end up trying to create extra VNICs for which we
did not make any reservation. FW can fail this request,
thereby making us lose active RSS contexts.
Suppose an RSS context is deleted already and we try to
process a delete request again, then the HWRM functions
will check for validity of the request and they simply
return if the resource is already freed. So, even for
delete-when-down cases, netif_running() check is not
necessary.
Remove the netif_running() condition check when deleting
an RSS context.
CWE: CWE-415: Double Free
CVSS Source: NVD
CVSS Base score: 7.8
CVSS Vector: (CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H)
CVEID: CVE-2026-46173
DESCRIPTION: In the Linux kernel, the following vulnerability has been resolved:
exit: prevent preemption of oopsing TASK_DEAD task
When an already-exiting task oopses, make_task_dead() currently calls
do_task_dead() with preemption enabled. That is forbidden:
do_task_dead() calls __schedule(), which has a comment saying "WARNING:
must be called with preemption disabled!".
If an oopsing task is preempted in do_task_dead(), between becoming
TASK_DEAD and entering the scheduler explicitly, bad things happen:
finish_task_switch() assumes that once the scheduler has switched away
from a TASK_DEAD task, the task can never run again and its stack is no
longer needed; but that assumption apparently doesn't hold if the dead
task was preempted (the SM_PREEMPT case).
This means that the scheduler ends up repeatedly dropping references on
the dead task's stack, which can lead to use-after-free or double-free
of the entire task stack; in other words, two tasks can end up running
on the same stack, resulting in various kinds of memory corruption.
(This does not just affect "recursively oopsing" tasks; it is enough to
oops once during task exit, for example in a file_operations::release
handler)
CWE: CWE-787: Out-of-bounds Write
CVSS Source: Linux
CVSS Base score: 7.8
CVSS Vector: (CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H)
CVEID: CVE-2026-46331
DESCRIPTION: In the Linux kernel, the following vulnerability has been resolved:
net/sched: fix pedit partial COW leading to page cache corruption
tcf_pedit_act() computes the COW range for skb_ensure_writable()
once before the key loop using tcfp_off_max_hint, but the hint does
not account for the runtime header offset added by typed keys. This
can leave part of the write region un-COW'd.
Fix by moving skb_ensure_writable() inside the per-key loop where
the actual write offset is known, and add overflow checking on the
offset arithmetic. For negative offsets (e.g. Ethernet header edits
at ingress), use skb_cow() to COW the headroom instead. Guard
offset_valid() against INT_MIN, where negation is undefined.
CWE: CWE-190: Integer Overflow or Wraparound
CVSS Source: Linux
CVSS Base score: 7.8
CVSS Vector: (CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H)
CVEID: CVE-2026-31411
DESCRIPTION: In the Linux kernel, the following vulnerability has been resolved:
net: atm: fix crash due to unvalidated vcc pointer in sigd_send()
Reproducer available at [1].
The ATM send path (sendmsg - vcc_sendmsg - sigd_send) reads the vcc
pointer from msg-vcc and uses it directly without any validation. This
pointer comes from userspace via sendmsg() and can be arbitrarily forged:
int fd = socket(AF_ATMSVC, SOCK_DGRAM, 0);
ioctl(fd, ATMSIGD_CTRL); // become ATM signaling daemon
struct msghdr msg = { .msg_iov = &iov, ... };
*(unsigned long *)(buf + 4) = 0xdeadbeef; // fake vcc pointer
sendmsg(fd, &msg, 0); // kernel dereferences 0xdeadbeef
In normal operation, the kernel sends the vcc pointer to the signaling
daemon via sigd_enq() when processing operations like connect(), bind(),
or listen(). The daemon is expected to return the same pointer when
responding. However, a malicious daemon can send arbitrary pointer values.
Fix this by introducing find_get_vcc() which validates the pointer by
searching through vcc_hash (similar to how sigd_close() iterates over
all VCCs), and acquires a reference via sock_hold() if found.
Since struct atm_vcc embeds struct sock as its first member, they share
the same lifetime. Therefore using sock_hold/sock_put is sufficient to
keep the vcc alive while it is being used.
Note that there may be a race with sigd_close() which could mark the vcc
with various flags (e.g., ATM_VF_RELEASED) after find_get_vcc() returns.
However, sock_hold() guarantees the memory remains valid, so this race
only affects the logical state, not memory safety.
[1]: https://gist.github.com/mrpre/1ba5949c45529c511152e2f4c755b0f3
CWE: CWE-476: NULL Pointer Dereference
CVSS Source: NVD
CVSS Base score: 5.5
CVSS Vector: (CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H)
CVEID: CVE-2026-43198
DESCRIPTION: In the Linux kernel, the following vulnerability has been resolved:
tcp: fix potential race in tcp_v6_syn_recv_sock()
Code in tcp_v6_syn_recv_sock() after the call to tcp_v4_syn_recv_sock()
is done too late.
After tcp_v4_syn_recv_sock(), the child socket is already visible
from TCP ehash table and other cpus might use it.
Since newinet-pinet6 is still pointing to the listener ipv6_pinfo
bad things can happen as syzbot found.
Move the problematic code in tcp_v6_mapped_child_init()
and call this new helper from tcp_v4_syn_recv_sock() before
the ehash insertion.
This allows the removal of one tcp_sync_mss(), since
tcp_v4_syn_recv_sock() will call it with the correct
context.
CWE: CWE-362: Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')
CVSS Source: Linux
CVSS Base score: 9.8
CVSS Vector: (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H)
CVEID: CVE-2025-22105
DESCRIPTION: In the Linux kernel, the following vulnerability has been resolved:
bonding: check xdp prog when set bond mode
Following operations can trigger a warning[1]:
ip netns add ns1
ip netns exec ns1 ip link add bond0 type bond mode balance-rr
ip netns exec ns1 ip link set dev bond0 xdp obj af_xdp_kern.o sec xdp
ip netns exec ns1 ip link set bond0 type bond mode broadcast
ip netns del ns1
When delete the namespace, dev_xdp_uninstall() is called to remove xdp
program on bond dev, and bond_xdp_set() will check the bond mode. If bond
mode is changed after attaching xdp program, the warning may occur.
Some bond modes (broadcast, etc.) do not support native xdp. Set bond mode
with xdp program attached is not good. Add check for xdp program when set
bond mode.
[1]
------------[ cut here ]------------
WARNING: CPU: 0 PID: 11 at net/core/dev.c:9912 unregister_netdevice_many_notify+0x8d9/0x930
Modules linked in:
CPU: 0 UID: 0 PID: 11 Comm: kworker/u4:0 Not tainted 6.14.0-rc4 #107
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.15.0-0-g2dd4b9b3f840-prebuilt.qemu.org 04/01/2014
Workqueue: netns cleanup_net
RIP: 0010:unregister_netdevice_many_notify+0x8d9/0x930
Code: 00 00 48 c7 c6 6f e3 a2 82 48 c7 c7 d0 b3 96 82 e8 9c 10 3e ...
RSP: 0018:ffffc90000063d80 EFLAGS: 00000282
RAX: 00000000ffffffa1 RBX: ffff888004959000 RCX: 00000000ffffdfff
RDX: 0000000000000000 RSI: 00000000ffffffea RDI: ffffc90000063b48
RBP: ffffc90000063e28 R08: ffffffff82d39b28 R09: 0000000000009ffb
R10: 0000000000000175 R11: ffffffff82d09b40 R12: ffff8880049598e8
R13: 0000000000000001 R14: dead000000000100 R15: ffffc90000045000
FS: 0000000000000000(0000) GS:ffff888007a00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000000d406b60 CR3: 000000000483e000 CR4: 00000000000006f0
Call Trace:
TASK
? __warn+0x83/0x130
? unregister_netdevice_many_notify+0x8d9/0x930
? report_bug+0x18e/0x1a0
? handle_bug+0x54/0x90
? exc_invalid_op+0x18/0x70
? asm_exc_invalid_op+0x1a/0x20
? unregister_netdevice_many_notify+0x8d9/0x930
? bond_net_exit_batch_rtnl+0x5c/0x90
cleanup_net+0x237/0x3d0
process_one_work+0x163/0x390
worker_thread+0x293/0x3b0
? __pfx_worker_thread+0x10/0x10
kthread+0xec/0x1e0
? __pfx_kthread+0x10/0x10
? __pfx_kthread+0x10/0x10
ret_from_fork+0x2f/0x50
? __pfx_kthread+0x10/0x10
ret_from_fork_asm+0x1a/0x30
/TASK
---[ end trace 0000000000000000 ]---
CVSS Source: NVD
CVSS Base score: 5.5
CVSS Vector: (CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H)
CVEID: CVE-2025-37980
DESCRIPTION: In the Linux kernel, the following vulnerability has been resolved:
block: fix resource leak in blk_register_queue() error path
When registering a queue fails after blk_mq_sysfs_register() is
successful but the function later encounters an error, we need
to clean up the blk_mq_sysfs resources.
Add the missing blk_mq_sysfs_unregister() call in the error path
to properly clean up these resources and prevent a memory leak.
CWE: CWE-401: Missing Release of Memory after Effective Lifetime
CVSS Source: NVD
CVSS Base score: 5.5
CVSS Vector: (CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H)
CVEID: CVE-2025-38015
DESCRIPTION: In the Linux kernel, the following vulnerability has been resolved:
dmaengine: idxd: fix memory leak in error handling path of idxd_alloc
Memory allocated for idxd is not freed if an error occurs during
idxd_alloc(). To fix it, free the allocated memory in the reverse order
of allocation before exiting the function in case of an error.
CWE: CWE-401: Missing Release of Memory after Effective Lifetime
CVSS Source: NVD
CVSS Base score: 5.5
CVSS Vector: (CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H)
CVEID: CVE-2025-38097
DESCRIPTION: In the Linux kernel, the following vulnerability has been resolved:
espintcp: remove encap socket caching to avoid reference leak
The current scheme for caching the encap socket can lead to reference
leaks when we try to delete the netns.
The reference chain is: xfrm_state - enacp_sk - netns
Since the encap socket is a userspace socket, it holds a reference on
the netns. If we delete the espintcp state (through flush or
individual delete) before removing the netns, the reference on the
socket is dropped and the netns is correctly deleted. Otherwise, the
netns may not be reachable anymore (if all processes within the ns
have terminated), so we cannot delete the xfrm state to drop its
reference on the socket.
This patch results in a small (~2% in my tests) performance
regression.
A GC-type mechanism could be added for the socket cache, to clear
references if the state hasn't been used "recently", but it's a lot
more complex than just not caching the socket.
CVSS Source: NVD
CVSS Base score: 5.5
CVSS Vector: (CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H)
CVEID: CVE-2025-38400
DESCRIPTION: In the Linux kernel, the following vulnerability has been resolved:
nfs: Clean up /proc/net/rpc/nfs when nfs_fs_proc_net_init() fails.
syzbot reported a warning below [1] following a fault injection in
nfs_fs_proc_net_init(). [0]
When nfs_fs_proc_net_init() fails, /proc/net/rpc/nfs is not removed.
Later, rpc_proc_exit() tries to remove /proc/net/rpc, and the warning
is logged as the directory is not empty.
Let's handle the error of nfs_fs_proc_net_init() properly.
[0]:
FAULT_INJECTION: forcing a failure.
name failslab, interval 1, probability 0, space 0, times 0
CPU: 1 UID: 0 PID: 6120 Comm: syz.2.27 Not tainted 6.16.0-rc1-syzkaller-00010-g2c4a1f3fe03e #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Call Trace:
TASK
dump_stack_lvl (lib/dump_stack.c:123)
should_fail_ex (lib/fault-inject.c:73 lib/fault-inject.c:174)
should_failslab (mm/failslab.c:46)
kmem_cache_alloc_noprof (mm/slub.c:4178 mm/slub.c:4204)
__proc_create (fs/proc/generic.c:427)
proc_create_reg (fs/proc/generic.c:554)
proc_create_net_data (fs/proc/proc_net.c:120)
nfs_fs_proc_net_init (fs/nfs/client.c:1409)
nfs_net_init (fs/nfs/inode.c:2600)
ops_init (net/core/net_namespace.c:138)
setup_net (net/core/net_namespace.c:443)
copy_net_ns (net/core/net_namespace.c:576)
create_new_namespaces (kernel/nsproxy.c:110)
unshare_nsproxy_namespaces (kernel/nsproxy.c:218 (discriminator 4))
ksys_unshare (kernel/fork.c:3123)
__x64_sys_unshare (kernel/fork.c:3190)
do_syscall_64 (arch/x86/entry/syscall_64.c:63 arch/x86/entry/syscall_64.c:94)
entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130)
/TASK
[1]:
remove_proc_entry: removing non-empty directory 'net/rpc', leaking at least 'nfs'
WARNING: CPU: 1 PID: 6120 at fs/proc/generic.c:727 remove_proc_entry+0x45e/0x530 fs/proc/generic.c:727
Modules linked in:
CPU: 1 UID: 0 PID: 6120 Comm: syz.2.27 Not tainted 6.16.0-rc1-syzkaller-00010-g2c4a1f3fe03e #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:remove_proc_entry+0x45e/0x530 fs/proc/generic.c:727
Code: 3c 02 00 0f 85 85 00 00 00 48 8b 93 d8 00 00 00 4d 89 f0 4c 89 e9 48 c7 c6 40 ba a2 8b 48 c7 c7 60 b9 a2 8b e8 33 81 1d ff 90 0f 0b 90 90 e9 5f fe ff ff e8 04 69 5e ff 90 48 b8 00 00 00 00 00
RSP: 0018:ffffc90003637b08 EFLAGS: 00010282
RAX: 0000000000000000 RBX: ffff88805f534140 RCX: ffffffff817a92c8
RDX: ffff88807da99e00 RSI: ffffffff817a92d5 RDI: 0000000000000001
RBP: ffff888033431ac0 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000001 R12: ffff888033431a00
R13: ffff888033431ae4 R14: ffff888033184724 R15: dffffc0000000000
FS: 0000555580328500(0000) GS:ffff888124a62000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f71733743e0 CR3: 000000007f618000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
TASK
sunrpc_exit_net+0x46/0x90 net/sunrpc/sunrpc_syms.c:76
ops_exit_list net/core/net_namespace.c:200 [inline]
ops_undo_list+0x2eb/0xab0 net/core/net_namespace.c:253
setup_net+0x2e1/0x510 net/core/net_namespace.c:457
copy_net_ns+0x2a6/0x5f0 net/core/net_namespace.c:574
create_new_namespaces+0x3ea/0xa90 kernel/nsproxy.c:110
unshare_nsproxy_namespaces+0xc0/0x1f0 kernel/nsproxy.c:218
ksys_unshare+0x45b/0xa40 kernel/fork.c:3121
__do_sys_unshare kernel/fork.c:3192 [inline]
__se_sys_unshare kernel/fork.c:3190 [inline]
__x64_sys_unshare+0x31/0x40 kernel/fork.c:3190
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xcd/0x490 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fa1a6b8e929
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 48 3d 01 f0 ff ff 73 01 c
---truncated---
CVSS Source: NVD
CVSS Base score: 5.5
CVSS Vector: (CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H)
CVEID: CVE-2025-38405
DESCRIPTION: In the Linux kernel, the following vulnerability has been resolved:
nvmet: fix memory leak of bio integrity
If nvmet receives commands with metadata there is a continuous memory
leak of kmalloc-128 slab or more precisely bio-bi_integrity.
Since commit bf4c89fc8797 ("block: don't call bio_uninit from bio_endio")
each user of bio_init has to use bio_uninit as well. Otherwise the bio
integrity is not getting free. Nvmet uses bio_init for inline bios.
Uninit the inline bio to complete deallocation of integrity in bio.
CWE: CWE-401: Missing Release of Memory after Effective Lifetime
CVSS Source: NVD
CVSS Base score: 5.5
CVSS Vector: (CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H)
CVEID: CVE-2025-38441
DESCRIPTION: In the Linux kernel, the following vulnerability has been resolved:
netfilter: flowtable: account for Ethernet header in nf_flow_pppoe_proto()
syzbot found a potential access to uninit-value in nf_flow_pppoe_proto()
Blamed commit forgot the Ethernet header.
BUG: KMSAN: uninit-value in nf_flow_offload_inet_hook+0x7e4/0x940 net/netfilter/nf_flow_table_inet.c:27
nf_flow_offload_inet_hook+0x7e4/0x940 net/netfilter/nf_flow_table_inet.c:27
nf_hook_entry_hookfn include/linux/netfilter.h:157 [inline]
nf_hook_slow+0xe1/0x3d0 net/netfilter/core.c:623
nf_hook_ingress include/linux/netfilter_netdev.h:34 [inline]
nf_ingress net/core/dev.c:5742 [inline]
__netif_receive_skb_core+0x4aff/0x70c0 net/core/dev.c:5837
__netif_receive_skb_one_core net/core/dev.c:5975 [inline]
__netif_receive_skb+0xcc/0xac0 net/core/dev.c:6090
netif_receive_skb_internal net/core/dev.c:6176 [inline]
netif_receive_skb+0x57/0x630 net/core/dev.c:6235
tun_rx_batched+0x1df/0x980 drivers/net/tun.c:1485
tun_get_user+0x4ee0/0x6b40 drivers/net/tun.c:1938
tun_chr_write_iter+0x3e9/0x5c0 drivers/net/tun.c:1984
new_sync_write fs/read_write.c:593 [inline]
vfs_write+0xb4b/0x1580 fs/read_write.c:686
ksys_write fs/read_write.c:738 [inline]
__do_sys_write fs/read_write.c:749 [inline]
CWE: CWE-908: Use of Uninitialized Resource
CVSS Source: NVD
CVSS Base score: 5.5
CVSS Vector: (CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H)
CVEID: CVE-2025-38470
DESCRIPTION: In the Linux kernel, the following vulnerability has been resolved:
net: vlan: fix VLAN 0 refcount imbalance of toggling filtering during runtime
Assuming the "rx-vlan-filter" feature is enabled on a net device, the
8021q module will automatically add or remove VLAN 0 when the net device
is put administratively up or down, respectively. There are a couple of
problems with the above scheme.
The first problem is a memory leak that can happen if the "rx-vlan-filter"
feature is disabled while the device is running:
# ip link add bond1 up type bond mode 0
# ethtool -K bond1 rx-vlan-filter off
# ip link del dev bond1
When the device is put administratively down the "rx-vlan-filter"
feature is disabled, so the 8021q module will not remove VLAN 0 and the
memory will be leaked [1].
Another problem that can happen is that the kernel can automatically
delete VLAN 0 when the device is put administratively down despite not
adding it when the device was put administratively up since during that
time the "rx-vlan-filter" feature was disabled. null-ptr-unref or
bug_on[2] will be triggered by unregister_vlan_dev() for refcount
imbalance if toggling filtering during runtime:
$ ip link add bond0 type bond mode 0
$ ip link add link bond0 name vlan0 type vlan id 0 protocol 802.1q
$ ethtool -K bond0 rx-vlan-filter off
$ ifconfig bond0 up
$ ethtool -K bond0 rx-vlan-filter on
$ ifconfig bond0 down
$ ip link del vlan0
Root cause is as below:
step1: add vlan0 for real_dev, such as bond, team.
register_vlan_dev
vlan_vid_add(real_dev,htons(ETH_P_8021Q),0) //refcnt=1
step2: disable vlan filter feature and enable real_dev
step3: change filter from 0 to 1
vlan_device_event
vlan_filter_push_vids
ndo_vlan_rx_add_vid //No refcnt added to real_dev vlan0
step4: real_dev down
vlan_device_event
vlan_vid_del(dev, htons(ETH_P_8021Q), 0); //refcnt=0
vlan_info_rcu_free //free vlan0
step5: delete vlan0
unregister_vlan_dev
BUG_ON(!vlan_info); //vlan_info is null
Fix both problems by noting in the VLAN info whether VLAN 0 was
automatically added upon NETDEV_UP and based on that decide whether it
should be deleted upon NETDEV_DOWN, regardless of the state of the
"rx-vlan-filter" feature.
[1]
unreferenced object 0xffff8880068e3100 (size 256):
comm "ip", pid 384, jiffies 4296130254
hex dump (first 32 bytes):
00 20 30 0d 80 88 ff ff 00 00 00 00 00 00 00 00 . 0.............
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
backtrace (crc 81ce31fa):
__kmalloc_cache_noprof+0x2b5/0x340
vlan_vid_add+0x434/0x940
vlan_device_event.cold+0x75/0xa8
notifier_call_chain+0xca/0x150
__dev_notify_flags+0xe3/0x250
rtnl_configure_link+0x193/0x260
rtnl_newlink_create+0x383/0x8e0
__rtnl_newlink+0x22c/0xa40
rtnl_newlink+0x627/0xb00
rtnetlink_rcv_msg+0x6fb/0xb70
netlink_rcv_skb+0x11f/0x350
netlink_unicast+0x426/0x710
netlink_sendmsg+0x75a/0xc20
__sock_sendmsg+0xc1/0x150
____sys_sendmsg+0x5aa/0x7b0
___sys_sendmsg+0xfc/0x180
[2]
kernel BUG at net/8021q/vlan.c:99!
Oops: invalid opcode: 0000 [#1] SMP KASAN PTI
CPU: 0 UID: 0 PID: 382 Comm: ip Not tainted 6.16.0-rc3 #61 PREEMPT(voluntary)
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996),
BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014
RIP: 0010:unregister_vlan_dev (net/8021q/vlan.c:99 (discriminator 1))
RSP: 0018:ffff88810badf310 EFLAGS: 00010246
RAX: 0000000000000000 RBX: ffff88810da84000 RCX: ffffffffb47ceb9a
RDX: dffffc0000000000 RSI: 0000000000000008 RDI: ffff88810e8b43c8
RBP: 0000000000000000 R08: 0000000000000000 R09: fffffbfff6cefe80
R10: ffffffffb677f407 R11: ffff88810badf3c0 R12: ffff88810e8b4000
R13: 0000000000000000 R14: ffff88810642a5c0 R15: 000000000000017e
FS: 00007f1ff68c20c0(0000) GS:ffff888163a24000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f1ff5dad240 CR3: 0000000107e56000 CR4: 00000000000006f0
Call Trace:
TASK
---truncated---
CVSS Source: NVD
CVSS Base score: 5.5
CVSS Vector: (CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H)
CVEID: CVE-2025-39866
DESCRIPTION: In the Linux kernel, the following vulnerability has been resolved:
fs: writeback: fix use-after-free in __mark_inode_dirty()
An use-after-free issue occurred when __mark_inode_dirty() get the
bdi_writeback that was in the progress of switching.
CPU: 1 PID: 562 Comm: systemd-random- Not tainted 6.6.56-gb4403bd46a8e #1
......
pstate: 60400005 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : __mark_inode_dirty+0x124/0x418
lr : __mark_inode_dirty+0x118/0x418
sp : ffffffc08c9dbbc0
........
Call trace:
__mark_inode_dirty+0x124/0x418
generic_update_time+0x4c/0x60
file_modified+0xcc/0xd0
ext4_buffered_write_iter+0x58/0x124
ext4_file_write_iter+0x54/0x704
vfs_write+0x1c0/0x308
ksys_write+0x74/0x10c
__arm64_sys_write+0x1c/0x28
invoke_syscall+0x48/0x114
el0_svc_common.constprop.0+0xc0/0xe0
do_el0_svc+0x1c/0x28
el0_svc+0x40/0xe4
el0t_64_sync_handler+0x120/0x12c
el0t_64_sync+0x194/0x198
Root cause is:
systemd-random-seed kworker
----------------------------------------------------------------------
___mark_inode_dirty inode_switch_wbs_work_fn
spin_lock(&inode-i_lock);
inode_attach_wb
locked_inode_to_wb_and_lock_list
get inode-i_wb
spin_unlock(&inode-i_lock);
spin_lock(&wb-list_lock)
spin_lock(&inode-i_lock)
inode_io_list_move_locked
spin_unlock(&wb-list_lock)
spin_unlock(&inode-i_lock)
spin_lock(&old_wb-list_lock)
inode_do_switch_wbs
spin_lock(&inode-i_lock)
inode-i_wb = new_wb
spin_unlock(&inode-i_lock)
spin_unlock(&old_wb-list_lock)
wb_put_many(old_wb, nr_switched)
cgwb_release
old wb released
wb_wakeup_delayed() accesses wb,
then trigger the use-after-free
issue
Fix this race condition by holding inode spinlock until
wb_wakeup_delayed() finished.
CWE: CWE-416: Use After Free
CVSS Source: NVD
CVSS Base score: 7.8
CVSS Vector: (CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H)
CVEID: CVE-2025-40134
DESCRIPTION: In the Linux kernel, the following vulnerability has been resolved:
dm: fix NULL pointer dereference in __dm_suspend()
There is a race condition between dm device suspend and table load that
can lead to null pointer dereference. The issue occurs when suspend is
invoked before table load completes:
BUG: kernel NULL pointer dereference, address: 0000000000000054
Oops: 0000 [#1] PREEMPT SMP PTI
CPU: 6 PID: 6798 Comm: dmsetup Not tainted 6.6.0-g7e52f5f0ca9b #62
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.1-2.fc37 04/01/2014
RIP: 0010:blk_mq_wait_quiesce_done+0x0/0x50
Call Trace:
TASK
blk_mq_quiesce_queue+0x2c/0x50
dm_stop_queue+0xd/0x20
__dm_suspend+0x130/0x330
dm_suspend+0x11a/0x180
dev_suspend+0x27e/0x560
ctl_ioctl+0x4cf/0x850
dm_ctl_ioctl+0xd/0x20
vfs_ioctl+0x1d/0x50
__se_sys_ioctl+0x9b/0xc0
__x64_sys_ioctl+0x19/0x30
x64_sys_call+0x2c4a/0x4620
do_syscall_64+0x9e/0x1b0
The issue can be triggered as below:
T1 T2
dm_suspend table_load
__dm_suspend dm_setup_md_queue
dm_mq_init_request_queue
blk_mq_init_allocated_queue
= q-mq_ops = set-ops; (1)
dm_stop_queue / dm_wait_for_completion
= q-tag_set NULL pointer! (2)
= q-tag_set = set; (3)
Fix this by checking if a valid table (map) exists before performing
request-based suspend and waiting for target I/O. When map is NULL,
skip these table-dependent suspend steps.
Even when map is NULL, no I/O can reach any target because there is
no table loaded; I/O submitted in this state will fail early in the
DM layer. Skipping the table-dependent suspend logic in this case
is safe and avoids NULL pointer dereferences.
CVSS Source: Red Hat
CVSS Base score: 4.7
CVSS Vector: (CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H)
CVEID: CVE-2026-23060
DESCRIPTION: In the Linux kernel, the following vulnerability has been resolved:
crypto: authencesn - reject too-short AAD (assoclen8) to match ESP/ESN spec
authencesn assumes an ESP/ESN-formatted AAD. When assoclen is shorter than
the minimum expected length, crypto_authenc_esn_decrypt() can advance past
the end of the destination scatterlist and trigger a NULL pointer dereference
in scatterwalk_map_and_copy(), leading to a kernel panic (DoS).
Add a minimum AAD length check to fail fast on invalid inputs.
CWE: CWE-476: NULL Pointer Dereference
CVSS Source: NVD
CVSS Base score: 5.5
CVSS Vector: (CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H)
CVEID: CVE-2026-31677
DESCRIPTION: In the Linux kernel, the following vulnerability has been resolved:
crypto: af_alg - limit RX SG extraction by receive buffer budget
Make af_alg_get_rsgl() limit each RX scatterlist extraction to the
remaining receive buffer budget.
af_alg_get_rsgl() currently uses af_alg_readable() only as a gate
before extracting data into the RX scatterlist. Limit each extraction
to the remaining af_alg_rcvbuf(sk) budget so that receive-side
accounting matches the amount of data attached to the request.
If skcipher cannot obtain enough RX space for at least one chunk while
more data remains to be processed, reject the recvmsg call instead of
rounding the request length down to zero.
CVSS Source: NVD
CVSS Base score: 5.5
CVSS Vector: (CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H)
Affected Products and Versions
| Affected Product(s) | Version(s) |
| IBM DataPower Gateway 10.6CD | 10.6.1 - 10.6.6 |
| IBM DataPower Gateway 11.0.0 | 11.0.0.0 - 11.0.0.2 |
Remediation/Fixes
IBM strongly advises upgrading as soon as possible.
Known Issue: DT500623
| Affected Versions | Fixed in Release |
| IBM DataPower Gateway 10.6CD 10.6.1 - 10.6.6 | 11.0.0.3 |
| IBM DataPower Gateway 11.0.0 11.0.0.0 - 11.0.0.2 | 11.0.0.3 |
Workarounds and Mitigations
None
Get Notified about Future Security Bulletins
References
Acknowledgement
Change History
28 Sep 2026: Initial Publication
*The CVSS Environment Score is customer environment specific and will ultimately impact the Overall CVSS Score. Customers can evaluate the impact of this vulnerability in their environments by accessing the links in the Reference section of this Security Bulletin.
Disclaimer
According to the Forum of Incident Response and Security Teams (FIRST), the Common Vulnerability Scoring System (CVSS) is an "industry open standard designed to convey vulnerability severity and help to determine urgency and priority of response." IBM PROVIDES THE CVSS SCORES ""AS IS"" WITHOUT WARRANTY OF ANY KIND, INCLUDING THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. CUSTOMERS ARE RESPONSIBLE FOR ASSESSING THE IMPACT OF ANY ACTUAL OR POTENTIAL SECURITY VULNERABILITY. In addition to other efforts to address potential vulnerabilities, IBM periodically updates the record of components contained in our product offerings. As part of that effort, if IBM identifies previously unidentified packages in a product/service inventory, we address relevant vulnerabilities regardless of CVE date. Inclusion of an older CVEID does not demonstrate that the referenced product has been used by IBM since that date, nor that IBM was aware of a vulnerability as of that date. We are making clients aware of relevant vulnerabilities as we become aware of them. "Affected Products and Versions" referenced in IBM Security Bulletins are intended to be only products and versions that are supported by IBM and have not passed their end-of-support or warranty date. Thus, failure to reference unsupported or extended-support products and versions in this Security Bulletin does not constitute a determination by IBM that they are unaffected by the vulnerability. Reference to one or more unsupported versions in this Security Bulletin shall not create an obligation for IBM to provide fixes for any unsupported or extended-support products or versions.
Document Location
Worldwide
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Document Information
Modified date:
28 September 2026
Initial Publish date:
28 September 2026
UID
ibm17289791