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Security Bulletin: Technical Support Appliance - potential denial of service conditions in underlying Linux kernel

Security Bulletin


Summary

Multiple vulnerabilities have been identified in the Linux kernel affecting subsystems such as ext4 filesystem, IPv6 networking, framebuffer console, and other optional components (e.g., Bluetooth, RDMA, NFS, NVMe, USB audio). These issues primarily involve race conditions, use-after-free scenarios, and buffer boundary checks which could lead to system instability or denial of service under specific conditions.

Vulnerability Details

CVEID:   CVE-2022-50673
DESCRIPTION:   In the Linux kernel, the following vulnerability has been resolved: ext4: fix use-after-free in ext4_orphan_cleanup I caught a issue as follows: ================================================================== BUG: KASAN: use-after-free in __list_add_valid+0x28/0x1a0 Read of size 8 at addr ffff88814b13f378 by task mount/710 CPU: 1 PID: 710 Comm: mount Not tainted 6.1.0-rc3-next #370 Call Trace: TASK dump_stack_lvl+0x73/0x9f print_report+0x25d/0x759 kasan_report+0xc0/0x120 __asan_load8+0x99/0x140 __list_add_valid+0x28/0x1a0 ext4_orphan_cleanup+0x564/0x9d0 [ext4] __ext4_fill_super+0x48e2/0x5300 [ext4] ext4_fill_super+0x19f/0x3a0 [ext4] get_tree_bdev+0x27b/0x450 ext4_get_tree+0x19/0x30 [ext4] vfs_get_tree+0x49/0x150 path_mount+0xaae/0x1350 do_mount+0xe2/0x110 __x64_sys_mount+0xf0/0x190 do_syscall_64+0x35/0x80 entry_SYSCALL_64_after_hwframe+0x63/0xcd /TASK [...] ================================================================== Above issue may happen as follows: ------------------------------------- ext4_fill_super ext4_orphan_cleanup --- loop1: assume last_orphan is 12 --- list_add(&EXT4_I(inode)-i_orphan, &EXT4_SB(sb)-s_orphan) ext4_truncate -- return 0 ext4_inode_attach_jinode -- return -ENOMEM iput(inode) -- free inode12 --- loop2: last_orphan is still 12 --- list_add(&EXT4_I(inode)-i_orphan, &EXT4_SB(sb)-s_orphan); // use inode12 and trigger UAF To solve this issue, we need to propagate the return value of ext4_inode_attach_jinode() appropriately.
CVSS Source:   Red Hat
CVSS Base score:   7
CVSS Vector:   (CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H)

CVEID:   CVE-2025-38403
DESCRIPTION:   In the Linux kernel, the following vulnerability has been resolved: vsock/vmci: Clear the vmci transport packet properly when initializing it In vmci_transport_packet_init memset the vmci_transport_packet before populating the fields to avoid any uninitialised data being left in the structure.
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-2025-40135
DESCRIPTION:   In the Linux kernel, the following vulnerability has been resolved: ipv6: use RCU in ip6_xmit() Use RCU in ip6_xmit() in order to use dst_dev_rcu() to prevent possible UAF.
CVSS Source:   Red Hat
CVSS Base score:   7
CVSS Vector:   (CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H)

CVEID:   CVE-2025-40158
DESCRIPTION:   In the Linux kernel, the following vulnerability has been resolved: ipv6: use RCU in ip6_output() Use RCU in ip6_output() in order to use dst_dev_rcu() to prevent possible UAF. We can remove rcu_read_lock()/rcu_read_unlock() pairs from ip6_finish_output2().
CVSS Source:   Red Hat
CVSS Base score:   7
CVSS Vector:   (CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H)

CVEID:   CVE-2025-40170
DESCRIPTION:   In the Linux kernel, the following vulnerability has been resolved: net: use dst_dev_rcu() in sk_setup_caps() Use RCU to protect accesses to dst-dev from sk_setup_caps() and sk_dst_gso_max_size(). Also use dst_dev_rcu() in ip6_dst_mtu_maybe_forward(), and ip_dst_mtu_maybe_forward(). ip4_dst_hoplimit() can use dst_dev_net_rcu().
CVSS Source:   Red Hat
CVSS Base score:   7.4
CVSS Vector:   (CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H)

CVEID:   CVE-2025-40269
DESCRIPTION:   In the Linux kernel, the following vulnerability has been resolved: ALSA: usb-audio: Fix potential overflow of PCM transfer buffer The PCM stream data in USB-audio driver is transferred over USB URB packet buffers, and each packet size is determined dynamically. The packet sizes are limited by some factors such as wMaxPacketSize USB descriptor. OTOH, in the current code, the actually used packet sizes are determined only by the rate and the PPS, which may be bigger than the size limit above. This results in a buffer overflow, as reported by syzbot. Basically when the limit is smaller than the calculated packet size, it implies that something is wrong, most likely a weird USB descriptor. So the best option would be just to return an error at the parameter setup time before doing any further operations. This patch introduces such a sanity check, and returns -EINVAL when the packet size is greater than maxpacksize. The comparison with ep-packsize[1] alone should suffice since it's always equal or greater than ep-packsize[0].
CVSS Source:   Red Hat
CVSS Base score:   7.3
CVSS Vector:   (CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:H)

CVEID:   CVE-2025-68349
DESCRIPTION:   In the Linux kernel, the following vulnerability has been resolved: NFSv4/pNFS: Clear NFS_INO_LAYOUTCOMMIT in pnfs_mark_layout_stateid_invalid Fixes a crash when layout is null during this call stack: write_inode - nfs4_write_inode - pnfs_layoutcommit_inode pnfs_set_layoutcommit relies on the lseg refcount to keep the layout around. Need to clear NFS_INO_LAYOUTCOMMIT otherwise we might attempt to reference a null layout.
CVSS Source:   Red Hat
CVSS Base score:   7.5
CVSS Vector:   (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H)

CVEID:   CVE-2026-22998
DESCRIPTION:   In the Linux kernel, the following vulnerability has been resolved: nvme-tcp: fix NULL pointer dereferences in nvmet_tcp_build_pdu_iovec Commit efa56305908b ("nvmet-tcp: Fix a kernel panic when host sends an invalid H2C PDU length") added ttag bounds checking and data_offset validation in nvmet_tcp_handle_h2c_data_pdu(), but it did not validate whether the command's data structures (cmd-req.sg and cmd-iov) have been properly initialized before processing H2C_DATA PDUs. The nvmet_tcp_build_pdu_iovec() function dereferences these pointers without NULL checks. This can be triggered by sending H2C_DATA PDU immediately after the ICREQ/ICRESP handshake, before sending a CONNECT command or NVMe write command. Attack vectors that trigger NULL pointer dereferences: 1. H2C_DATA PDU sent before CONNECT → both pointers NULL 2. H2C_DATA PDU for READ command → cmd-req.sg allocated, cmd-iov NULL 3. H2C_DATA PDU for uninitialized command slot → both pointers NULL The fix validates both cmd-req.sg and cmd-iov before calling nvmet_tcp_build_pdu_iovec(). Both checks are required because: - Uninitialized commands: both NULL - READ commands: cmd-req.sg allocated, cmd-iov NULL - WRITE commands: both allocated
CWE:   CWE-476: NULL Pointer Dereference
CVSS Source:   NVD
CVSS Base score:   7.5
CVSS Vector:   (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H)

Affected Products and Versions

Affected Product(s)Version(s)
Technical Support ApplianceAll

Remediation/Fixes

Update the IBM Technical Support Appliance to 3.1.2.  Refer to online support documentation on how to perform an update.

Workarounds and Mitigations

None

Get Notified about Future Security Bulletins

References

Off

Acknowledgement

Change History

26 Mar 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:
26 March 2026

Initial Publish date:
26 March 2026

UID

ibm17267688