A fix is available
APAR status
Closed as program error.
Error description
User reports abend with symptom string returned ABN= 0C4-00000010,LOC=CSQXRCTL.CSQXBPAL Change Team finds the problem occurs when a client application issues an MQGET with MQGMO_PROPERTIES_IN_HANDLE, and the combined length of the message data and message properties is larger than the staging buffer originally allocated by the CHINIT. In function rriAddMPHToAPIReply, MQ attempts to allocate a larger buffer, but the calculation of the required buffer size is incorrect and results in a buffer which is still too small. The processing then goes on to copy data beyond the end of the allocated buffer causing a storage overlay. During the Hursley recreate the overlay goes into unallocated storage and results in a dump with the symptom string : ABN=0C4-00000011,M=CSQXDISP, LOC=CSQXRCTL.CMQXRSRV In the user reported case the storage beyond the end of the buffer was allocated, so the overlay corrupted the data in that storage and caused the various 0C4 abends reported.
Local fix
Problem summary
**************************************************************** * USERS AFFECTED: All users of IBM MQ for z/OS Version 9 * * Release 0 Modification 0, Release 1 * * Modification 0 and Release 2 Modification 0. * **************************************************************** * PROBLEM DESCRIPTION: Storage overlay in the channel * * initiator address space leading to * * unpredictable symptoms including: * * * * - S0C4 abends * * - client connections failing with * * MQRC_CHANNEL_NOT_AVAILABLE (2537) * * - channels terminating or hanging * **************************************************************** While returning a message containing message properties, rriAddMPHToMQIReply was called to add the properties to the reply transmission. The chinit detected that the existing buffer was not large enough to contain the properties, and attempted to allocate a new buffer. However an error caused the new buffer to be too small. When the properties were copied to this buffer, they were copied to storage beyond the end of the new buffer, leading to potential storage overlay and/or abend 0C4.
Problem conclusion
rriAddMPHToMQIReply has been changed to ensure a staging area that is big enough to contain the message and properties is correctly allocated.
Temporary fix
Comments
APAR Information
APAR number
PH05676
Reported component name
IBM MQ Z/OS V9
Reported component ID
5655MQ900
Reported release
000
Status
CLOSED PER
PE
NoPE
HIPER
YesHIPER
Special Attention
NoSpecatt / Xsystem
Submitted date
2018-11-23
Closed date
2021-05-14
Last modified date
2021-06-02
APAR is sysrouted FROM one or more of the following:
PH00443
APAR is sysrouted TO one or more of the following:
UI60629 UI60630 UI75408
Modules/Macros
CMQXRSRV
Fix information
Fixed component name
IBM MQ Z/OS V9
Fixed component ID
5655MQ900
Applicable component levels
R200 PSY UI75408
UP21/05/29 P F105 ¢
Fix is available
Select the PTF appropriate for your component level. You will be required to sign in. Distribution on physical media is not available in all countries.
[{"Line of Business":{"code":"LOB45","label":"Automation"},"Business Unit":{"code":"BU053","label":"Cloud & Data Platform"},"Product":{"code":"SSYHRD","label":"IBM MQ"},"Platform":[{"code":"PF025","label":"Platform Independent"}],"Version":"9.0"}]
Document Information
Modified date:
03 June 2021