CVE-2026-98477
Received Received - Intake

NULL Pointer Dereference in Linux Kernel perf/core

Publication date: 2026-10-18

Last updated on: 2026-10-18

Assigner: kernel.org

Description
In the Linux kernel, the following vulnerability has been resolved: perf/core: Fix NULL pmu_ctx passed to pmu->sched_task() perf_pmu_sched_task() returns early when cpuctx->task_ctx is set, and cpc->task_epc is only non-NULL while a task context is scheduled in on this CPU. __perf_pmu_sched_task() therefore always passes NULL: Unable to handle kernel NULL pointer dereference at virtual address 00 pc : armv8pmu_sched_task+0x14/0x50 Call trace: armv8pmu_sched_task+0x14/0x50 (P) perf_pmu_sched_task+0xac/0x108 __perf_event_task_sched_out+0x6c/0xe0 Pass &cpc->epc instead, the CPU-wide context for this PMU, which the function already dereferences a few lines up to find pmu. armv8pmu_sched_task() is the only in-tree implementation that dereferences the argument, and it only reads ->pmu, so the oops needs BRBE, added in v6.17.

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Meta Information

Published
2026-10-18
Last Modified
2026-10-18
Generated
2026-10-19
AI Q&A
2026-10-18
EPSS Evaluated
N/A
NVD
CVE-2026-98477
EUVD
EUVD-2026-103717

Affected Vendors & Products

Showing 5 associated CPEs
Vendor Product Version / Range
Linux Linux bd27568117664b8b3e259721393df420ed51f57b
Linux Linux bd27568117664b8b3e259721393df420ed51f57b
Linux Linux bd27568117664b8b3e259721393df420ed51f57b
Linux Linux bd27568117664b8b3e259721393df420ed51f57b
Linux Linux 6.2

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Exploitability

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CWE ID Description
CWE-UNKNOWN

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Executive Summary

This vulnerability is a NULL pointer dereference flaw in the Linux kernel's perf/core subsystem. It occurs when perf_pmu_sched_task() incorrectly passes a NULL value to armv8pmu_sched_task(), leading to a kernel crash. The issue arises because the function returns early under certain conditions without properly handling the CPU-wide context for the PMU (Performance Monitoring Unit).

Detection Guidance

This vulnerability is specific to the Linux kernel's perf subsystem and may cause a kernel NULL pointer dereference. Detection typically involves checking kernel logs for oops messages or crashes related to perf or PMU (Performance Monitoring Unit) operations. Monitor system logs for errors like 'Unable to handle kernel NULL pointer dereference' or crashes in perf-related functions.

Impact Analysis

This vulnerability can cause system instability or crashes on affected Linux systems. If exploited, it may lead to denial-of-service conditions, where the system becomes unresponsive or requires a reboot. Systems using the armv8pmu_sched_task() function, particularly those with BRBE enabled (added in Linux v6.17), are at risk.

Compliance Impact

This vulnerability is a kernel NULL pointer dereference in the Linux perf subsystem, which could lead to system crashes or instability. It does not directly relate to data privacy or security controls required by GDPR or HIPAA, as it affects performance monitoring rather than data handling or access control mechanisms.

Mitigation Strategies

Apply the latest Linux kernel patches that address this issue. If you are using a vulnerable kernel version, update to a patched version where this issue has been resolved. Restart systems after applying patches to ensure the updated kernel is running.

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