CVE-2026-99125
Received
Received - Intake
Double PMU Stop Callback Handling in Linux Kernel
Vulnerability report for CVE-2026-99125, including description, CVSS score, EPSS score, affected products, exploitability, helpful resources, and attack-flow context.
Publication date: 2026-10-28
Last updated on: 2026-10-28
Assigner: kernel.org
Description
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().
CVSS Scores
EPSS Scores
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Meta Information
Helpful Resources
Exploitability
CWE
KEV
| CWE ID | Description |
|---|---|
| CWE-UNKNOWN |
