CVE intelligence and bounded remediation

CVE-2025-37878 — Linux Linux Kernel security vulnerability

In the Linux kernel, the following vulnerability has been resolved: perf/core: Fix WARN_ON(!ctx) in __free_event() for partial init Move the get_ctx(child_ctx) call and the child_event->ctx assignment to occur immediately after the child event is allocated. Ensure that child_event->ctx is non-NULL before any subsequent error path within inherit_event calls free_event(), satisfying the assumptions of the cleanup code. Details: There's no clear Fixes tag, because this bug is a side-effect of multiple interacting commits over time (up to 15 years old), not a single regression. The code initially incremented refcount then assigned context immediately after the child_event was created. Later, an early validity check for child_event was added before the refcount/assignment. Even later, a WARN_ON_ONCE() cleanup check was added, assuming event->ctx is valid if the pmu_ctx is valid. The problem is that the WARN_ON_ONCE() could trigger after the initial check passed but before child_event->ctx was assigned, violating its precondition. The solution is to assign child_event->ctx right after its initial validation. This ensures the context exists for any subsequent checks or cleanup routines…

Severity

Medium

CVSS

5.5 (3.1)

Published

2025-05-09

CISA KEV

Not currently listed

Ecosystem

linux/kernel

Weaknesses

CWE-617