{"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:\n\nperf/core: Fix NULL pmu_ctx passed to pmu->sched_task()\n\nperf_pmu_sched_task() returns early when cpuctx->task_ctx is set, and\ncpc->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","slug":"CVE-2026-98477","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nperf/core: Fix NULL pmu_ctx passed to pmu->sched_task()\n\nperf_pmu_sched_task() returns early when cpuctx->task_ctx is set, and\ncpc->task_epc is only non-NULL while a task context is scheduled in on\nthis CPU. __perf_pmu_sched_task() therefore always passes NULL:\n\n  Unable to handle kernel NULL pointer dereference at virtual address 00\n  pc : armv8pmu_sched_task+0x14/0x50\n  Call trace:\n   armv8pmu_sched_task+0x14/0x50 (P)\n   perf_pmu_sched_task+0xac/0x108\n   __perf_event_task_sched_out+0x6c/0xe0\n\nPass &cpc->epc instead, the CPU-wide context for this PMU, which the\nfunction already dereferences a few lines up to find pmu.\n\narmv8pmu_sched_task() is the only in-tree implementation that\ndereferences the argument, and it only reads ->pmu, so the oops needs\nBRBE, added in v6.17.\n\n## Affected\n\n- `Linux >= bd27568117664b8b3e259721393df420ed51f57b < 98181f9721f75f1a544dc563b0d8fed1d5c398d5`\n- `Linux >= bd27568117664b8b3e259721393df420ed51f57b < b5409311b606d536cc485f3706c242c2afa93edb`\n- `Linux >= bd27568117664b8b3e259721393df420ed51f57b < 249a2bd87a0e57dc28f36e992807edc9cae309b5`\n- `Linux >= bd27568117664b8b3e259721393df420ed51f57b < ec15f6a50183fc01f470af74ad49900fb3731fca`\n- `Linux >= bd27568117664b8b3e259721393df420ed51f57b < 36bb85cf36cab15fb611cb44b78a5df06e4e69a2`\n- `Linux 6.2`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.\n\n## Vendor advisories\n\n- **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)","depth":"sunlit","depthScore":30,"depthScoreParts":{"impact":30.3,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[{"seq":225660,"id":"CVE-2026-98477","ts":1792498339377,"field":"cvss","old":null,"new":"5.5"},{"seq":225659,"id":"CVE-2026-98477","ts":1792498339377,"field":"severity","old":"none","new":"medium"}]}