In the Linux kernel, the following vulnerability has been resolved:
s390/pai: Handle multiple PMU stop callback invocations
Handle the following scenario:
The kernel protects itself against a very high sampling load and
throttles the sampling using:
perf_event_throttle() --> PMU->stop()
Shortly later the scheduler may terminate the task and removes it from the
CPU. It again calls
PMU->stop()
which results in two invocations of PMU->stop() called back to back.
Protect against this and check the PERF_HES_STOPPED bit on function
entry. If it is already set return.
Clear bit PERF_HES_STOPPED in PMU->start().
Prohibit ioctl(fd, PERF_EVENT_IOC_PERIOD, ...) call for this event.
It sets perf_event::event_limit to a positive value and causes
perf_event_overflow() to invoke pai_stop() call back function when
perf_event::event_limit hits zero. This is not supported because the
sample events CRYPTO_ALL and NNPA_ALL are only taken at schedule out
of a task.
Use list_for_each_entry_safe() for safe iteration over syswide_list
in pai_have_samples().
s390/pai: Handle multiple PMU stop callback invocations
Handle the following scenario:
The kernel protects itself against a very high sampling load and
throttles the sampling using:
perf_event_throttle() --> PMU->stop()
Shortly later the scheduler may terminate the task and removes it from the
CPU. It again calls
PMU->stop()
which results in two invocations of PMU->stop() called back to back.
Protect against this and check the PERF_HES_STOPPED bit on function
entry. If it is already set return.
Clear bit PERF_HES_STOPPED in PMU->start().
Prohibit ioctl(fd, PERF_EVENT_IOC_PERIOD, ...) call for this event.
It sets perf_event::event_limit to a positive value and causes
perf_event_overflow() to invoke pai_stop() call back function when
perf_event::event_limit hits zero. This is not supported because the
sample events CRYPTO_ALL and NNPA_ALL are only taken at schedule out
of a task.
Use list_for_each_entry_safe() for safe iteration over syswide_list
in pai_have_samples().
Metrics
Affected Vendors & Products
Advisories
No advisories yet.
Fixes
Solution
No solution given by the vendor.
Workaround
No workaround given by the vendor.
References
History
Wed, 28 Oct 2026 12:30:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| First Time appeared |
Linux linux
|
|
| Vendors & Products |
Linux linux
|
Wed, 28 Oct 2026 12:00:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Weaknesses | CWE-665 |
Wed, 28 Oct 2026 10:45:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | In the Linux kernel, the following vulnerability has been resolved: s390/pai: Handle multiple PMU stop callback invocations Handle the following scenario: The kernel protects itself against a very high sampling load and throttles the sampling using: perf_event_throttle() --> PMU->stop() Shortly later the scheduler may terminate the task and removes it from the CPU. It again calls PMU->stop() which results in two invocations of PMU->stop() called back to back. Protect against this and check the PERF_HES_STOPPED bit on function entry. If it is already set return. Clear bit PERF_HES_STOPPED in PMU->start(). Prohibit ioctl(fd, PERF_EVENT_IOC_PERIOD, ...) call for this event. It sets perf_event::event_limit to a positive value and causes perf_event_overflow() to invoke pai_stop() call back function when perf_event::event_limit hits zero. This is not supported because the sample events CRYPTO_ALL and NNPA_ALL are only taken at schedule out of a task. Use list_for_each_entry_safe() for safe iteration over syswide_list in pai_have_samples(). | |
| Title | s390/pai: Handle multiple PMU stop callback invocations | |
| First Time appeared |
Linux
Linux linux Kernel |
|
| CPEs | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | |
| Vendors & Products |
Linux
Linux linux Kernel |
|
| References |
|
Projects
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MITRE
Status: PUBLISHED
Assigner: Linux
Published:
Updated: 2026-10-28T10:34:40.025Z
Reserved: 2026-09-25T10:25:14.393Z
Link: CVE-2026-99125
Vulnrichment
No data.
NVD
Status : Received
Published: 2026-10-28T11:17:32.210
Modified: 2026-10-28T11:17:32.210
Link: CVE-2026-99125
Redhat
No data.
OpenCVE Enrichment
Updated: 2026-10-28T12:15:14Z
Weaknesses