CVE-2026-23271
Description
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.
Statement
A race exists in the perf software event overflow handling where __perf_event_overflow can run without IRQs disabled for some callchains. This allows perf_event_release_kernel and perf_remove_from_context to free objects that the overflow path still expects to be present such as an attached BPF program. This is a classic lifetime bug and can result in use after free behavior which may manifest as a kernel crash. The issue is not network reachable and it requires local execution that can trigger perf overflow paths such as software events tracepoints or timer based sampling. Impact is denial of service. A conservative worst case includes limited confidentiality and integrity impact due to the use after free class but reliable privilege escalation is not demonstrated by the patch context.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
The following CVSS metrics and score provided are preliminary and subject to review.
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 5.8 | N/A | 7.8 |
| Attack Vector | Local | N/A | Local |
| Attack Complexity | High | N/A | Low |
| Privileges Required | Low | N/A | Low |
| User Interaction | None | N/A | None |
| Scope | Unchanged | N/A | Unchanged |
| Confidentiality | Low | N/A | High |
| Integrity Impact | Low | N/A | High |
| Availability Impact | High | N/A | High |
Vector
Red Hat: CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:L/I:L/A:H
cve.org: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Understanding the Weakness (CWE)
Integrity,Confidentiality
Technical Impact: Modify Application Data; Read Application Data
If a released resource is subsequently reused or reallocated, then an attempt to use the original resource might allow access to sensitive data that is associated with a different user or entity.
Other,Availability
Technical Impact: Other; DoS: Crash, Exit, or Restart
When a resource is released it might not be in an expected state, later attempts to access the resource may lead to resultant errors that may lead to a crash.
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