---
id: CVE-2026-98477
title: 'perf/core: Fix NULL pmu_ctx passed to pmu->sched_task()'
summary: |-
  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 ta…
severity: medium
cvss: 5.5
cvssVector: 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H'
cvssSource: vendor
cwe:
  - CWE-476
vendor: Linux
product: Linux
affected:
  - >-
    Linux >= bd27568117664b8b3e259721393df420ed51f57b <
    98181f9721f75f1a544dc563b0d8fed1d5c398d5
  - >-
    Linux >= bd27568117664b8b3e259721393df420ed51f57b <
    b5409311b606d536cc485f3706c242c2afa93edb
  - >-
    Linux >= bd27568117664b8b3e259721393df420ed51f57b <
    249a2bd87a0e57dc28f36e992807edc9cae309b5
  - >-
    Linux >= bd27568117664b8b3e259721393df420ed51f57b <
    ec15f6a50183fc01f470af74ad49900fb3731fca
  - >-
    Linux >= bd27568117664b8b3e259721393df420ed51f57b <
    36bb85cf36cab15fb611cb44b78a5df06e4e69a2
  - Linux 6.2
published: '2026-10-18'
updated: '2026-10-21'
sourceUpdated: '2026-10-21T12:55:10.170Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-98477'
references:
  - url: 'https://git.kernel.org/stable/c/98181f9721f75f1a544dc563b0d8fed1d5c398d5'
  - url: 'https://git.kernel.org/stable/c/b5409311b606d536cc485f3706c242c2afa93edb'
  - url: 'https://git.kernel.org/stable/c/249a2bd87a0e57dc28f36e992807edc9cae309b5'
  - url: 'https://git.kernel.org/stable/c/ec15f6a50183fc01f470af74ad49900fb3731fca'
  - url: 'https://git.kernel.org/stable/c/36bb85cf36cab15fb611cb44b78a5df06e4e69a2'
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-98477.json
  - url: 'https://access.redhat.com/security/cve/CVE-2026-98477'
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2554884'
  - url: 'https://www.cve.org/CVERecord?id=CVE-2026-98477'
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-98477'
  - url: >-
      https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-98477.mbox
tags:
  - cve.org
  - csaf
  - vex
  - red-hat
epss: 0.00168
epssPercentile: 0.06026
ingestedAt: '2026-10-18T15:45:12.295Z'
---

## Overview

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.

## Affected

- `Linux >= bd27568117664b8b3e259721393df420ed51f57b < 98181f9721f75f1a544dc563b0d8fed1d5c398d5`
- `Linux >= bd27568117664b8b3e259721393df420ed51f57b < b5409311b606d536cc485f3706c242c2afa93edb`
- `Linux >= bd27568117664b8b3e259721393df420ed51f57b < 249a2bd87a0e57dc28f36e992807edc9cae309b5`
- `Linux >= bd27568117664b8b3e259721393df420ed51f57b < ec15f6a50183fc01f470af74ad49900fb3731fca`
- `Linux >= bd27568117664b8b3e259721393df420ed51f57b < 36bb85cf36cab15fb611cb44b78a5df06e4e69a2`
- `Linux 6.2`

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.

## Vendor advisories

- **Red Hat VEX** · Moderate · affected: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 6, Red Hat Enterprise Linux 9, Red Hat OpenShift Container Platform 4 · no fix planned: Red Hat Enterprise Linux 6, Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 9, Red Hat OpenShift Container Platform 4 · updated 2026-10-20 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-98477.json)