Bug 2449565 (CVE-2026-23271)

Summary: CVE-2026-23271 kernel: perf: Fix __perf_event_overflow() vs perf_remove_from_context() race
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
Status: NEW --- QA Contact:
Severity: medium Docs Contact:
Priority: medium    
Version: unspecifiedCC: rhel-process-autobot, watson-tool-maintainers
Target Milestone: ---Keywords: Security
Target Release: ---   
Hardware: All   
OS: Linux   
Whiteboard:
Fixed In Version: Doc Type: ---
Doc Text:
A flaw was found in the Linux kernel's perf subsystem. A race condition exists between the `__perf_event_overflow()` function and functions like `perf_remove_from_context()` or `perf_event_exit_event()`. This occurs because `__perf_event_overflow()` may execute with only preemption disabled, allowing other operations to free resources, such as BPF (Berkeley Packet Filter) programs, that the overflow path expects to be available. This could lead to system instability or a denial of service.
 Story Points: ---
Clone Of: Environment:
Last Closed: Type: ---
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Embargoed:

Description OSIDB Bzimport 2026-03-20 09:02:51 UTC 
In the Linux kernel, the following vulnerability has been resolved:

perf: Fix __perf_event_overflow() vs perf_remove_from_context() race

Make sure that __perf_event_overflow() runs with IRQs disabled for all
possible callchains. Specifically the software events can end up running
it with only preemption disabled.

This opens up a race vs perf_event_exit_event() and friends that will go
and free various things the overflow path expects to be present, like
the BPF program.
Comment 1 Alexander B 2026-03-20 11:55:33 UTC 
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2026032031-CVE-2026-23271-657a@gregkh/T