CVE Catalog

CVE-2026-98268

Low risk· EPSS 4%
Published: Updated: Translated: NVD NIST

Exploitation Probability (EPSS)

Low risk
0.16%

4th percentile - higher than 4% of all known CVEs

Summary

In the Linux kernel, there is a null pointer access bug in the is_include_guest_event() function in the perf subsystem. During module unload with an active perf connection, the pmu pointer is freed, and later closing the connection leads to a null pointer dereference, causing a crash.

Risk Assessment

The risk includes potential system crash (kernel panic) during module unload with active perf sessions, which could lead to service disruptions.

Recommendation

It is recommended to update the Linux kernel to a version with the fix that adds a null pointer check in is_include_guest_event() and proper call ordering.

Other vulnerabilities in Linux kernel

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Original NVD description (English source)

In the Linux kernel, the following vulnerability has been resolved: perf: Fix null pointer access in is_include_guest_event() A typical module unload occurring event when there is an active perf connection leads to freeing of the pmu pointer. The call log is something like: .. __pmu_detach_event pmu_detach_event pmu_detach_events perf_pmu_unregister .. __pmu_detach_event() sets event->pmu to null. When the perf connection finally is closed, the following stack trace is observed: Oops: general protection fault, kernel NULL pointer dereference ... RIP: 0010:_free_event+0x3e/0x370 ... Call Trace: ... perf_event_release_kernel+0x260/0x2d0 perf_release+0x12/0x20 A call to mediated_pmu_unaccount_event() inside _free_event() is the root cause of this crash. Adding a check inside is_include_guest_event() ensures we don't accidentally access a null pmu ptr. In addition to this, we will now call mediated_pmu_unaccount_event() before clearing the pmu ptr so that nr_include_guest_events counts are maintained correctly.

Vulnerability data from NVD (NIST) · CISA KEV · EPSS