s390/pai: Support CPU hotplug for PMU PAI

MITRE NVD CVE.ORG JSON API

Summary

CVECVE-2026-97526
StatePUBLISHED
AssignerLinux
Source PriorityCVE Program / NVD first with legacy fallback
Published2026-09-25 11:17:02 UTC
Updated2026-09-25 11:17:02 UTC
DescriptionIn the Linux kernel, the following vulnerability has been resolved: s390/pai: Support CPU hotplug for PMU PAI The command 'perf stat -e pai_crypto/CRYPTO_ALL/ -- <command>' crashes the kernel when CPUs are hotplug added during that run. Root cause is the missing allocation of per-CPU data structures for that new CPU. The allocation is dynamic and the first event that has task context creates such a structure for each online CPU. This is not sufficient. CPUs may be offline during event creation and can be set online during the perf run time. For example commands # echo 0 > /sys/devices/system/cpu/cpu1/online # perf stat -e cycles -i -- stress-ng -t10s --matrix X # sleep 1 # echo 1 > /sys/devices/system/cpu/cpu1/online Currently without a CPU hotplug handler, that new CPU has no per-CPU data infrastructure. The scheduler runs PMU call back function pai_add() to install the PMU support for that CPU before the task is being scheduled on that new CPU. In pai_add() instructions mp = this_cpu_ptr(pai_root[idx].mapptr); cpump = mp->mapptr; return a NULL pointer and the result is a kernel panic as variable cpump is used inside that function. Add CPU hotplug support for CPU add and delete and create the necessary per-CPU data infrastructure during CPU hotplug add processing. Same for CPU hotplug remove. This is done when the CPU is offline to ensure the data structures are available when CPU is made online and tasks are scheduled on it. [[email protected]: fixup error path in pai_init()]

Vendor Declared Affected Products

SourceVendorProductVersionPlatforms
CNA Linux Linux affected 9f66572f2889a5e72a9d7e17787e52f03b1f7bd8 706e2bf330144995d123dccf32aaf1981ce5abc2 git Not specified
CNA Linux Linux affected 9f66572f2889a5e72a9d7e17787e52f03b1f7bd8 9ecc4d033879f7761f2df07e20cd2fbec00fd90b git Not specified
CNA Linux Linux affected 6.11 Not specified
CNA Linux Linux unaffected 6.11 semver Not specified
CNA Linux Linux unaffected 7.2.7 7.2.* semver Not specified
CNA Linux Linux unaffected 7.3-rc3 * original_commit_for_fix Not specified

References

ReferenceSourceLinkTags
git.kernel.org/stable/c/706e2bf330144995d123dccf32aaf1981ce5abc2 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org
git.kernel.org/stable/c/9ecc4d033879f7761f2df07e20cd2fbec00fd90b 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org
CVE Program record CVE.ORG www.cve.org canonical
NVD vulnerability detail NVD nvd.nist.gov canonical, analysis

© CVE.report 2026

Use of this information constitutes acceptance for use in an AS IS condition. There are NO warranties, implied or otherwise, with regard to this information or its use. Any use of this information is at the user's risk. It is the responsibility of user to evaluate the accuracy, completeness or usefulness of any information, opinion, advice or other content. EACH USER WILL BE SOLELY RESPONSIBLE FOR ANY consequences of his or her direct or indirect use of this web site. ALL WARRANTIES OF ANY KIND ARE EXPRESSLY DISCLAIMED. This site will NOT BE LIABLE FOR ANY DIRECT, INDIRECT or any other kind of loss.

CVE, CWE, and OVAL are registred trademarks of The MITRE Corporation and the authoritative source of CVE content is MITRE's CVE web site. This site includes MITRE data granted under the following license.

Free CVE JSON API cve.report/api

CVE.report and Source URL Uptime Status status.cve.report