{"id":"CVE-2026-31528","title":"perf: Make sure to use pmu_ctx->pmu for groups","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nperf: Make sure to use pmu_ctx->pmu for groups\n\nOliver reported that x86_pmu_del() ended up doing an out-of-bound memory access\nwhen group_sched_in() fails and needs to…","severity":"high","cvss":7.8,"cvssVector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","cvssSource":"cna","vendor":"Linux","product":"Linux","affected":["Linux >= bd27568117664b8b3e259721393df420ed51f57b < 656f35b463995bee024d948440128230aacd81e1","Linux >= bd27568117664b8b3e259721393df420ed51f57b < 3a696e84a8b1fafdd774bb30d62919faf844d9e4","Linux >= bd27568117664b8b3e259721393df420ed51f57b < 35f7914e54fe7f13654c22ee045b05e4b6d8062b","Linux >= bd27568117664b8b3e259721393df420ed51f57b < 4c759446046500a1a6785b25725725c3ff087ace","Linux >= bd27568117664b8b3e259721393df420ed51f57b < 4b9ce671960627b2505b3f64742544ae9801df97","Linux 6.2"],"ssvc":{"exploitation":"none","automatable":"no","technicalImpact":"total","timestamp":"2026-10-16T15:10:38.614462Z"},"published":"2026-04-22","updated":"2026-10-16","sourceUpdated":"2026-10-16T15:20:14.726Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-31528","references":[{"url":"https://git.kernel.org/stable/c/656f35b463995bee024d948440128230aacd81e1"},{"url":"https://git.kernel.org/stable/c/3a696e84a8b1fafdd774bb30d62919faf844d9e4"},{"url":"https://git.kernel.org/stable/c/35f7914e54fe7f13654c22ee045b05e4b6d8062b"},{"url":"https://git.kernel.org/stable/c/4c759446046500a1a6785b25725725c3ff087ace"},{"url":"https://git.kernel.org/stable/c/4b9ce671960627b2505b3f64742544ae9801df97"}],"tags":["cve.org"],"epss":0.00175,"epssPercentile":0.06547,"ingestedAt":"2026-10-16T17:24:46.660Z","slug":"CVE-2026-31528","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nperf: Make sure to use pmu_ctx->pmu for groups\n\nOliver reported that x86_pmu_del() ended up doing an out-of-bound memory access\nwhen group_sched_in() fails and needs to roll back.\n\nThis *should* be handled by the transaction callbacks, but he found that when\nthe group leader is a software event, the transaction handlers of the wrong PMU\nare used. Despite the move_group case in perf_event_open() and group_sched_in()\nusing pmu_ctx->pmu.\n\nTurns out, inherit uses event->pmu to clone the events, effectively undoing the\nmove_group case for all inherited contexts. Fix this by also making inherit use\npmu_ctx->pmu, ensuring all inherited counters end up in the same pmu context.\n\nSimilarly, __perf_event_read() should use equally use pmu_ctx->pmu for the\ngroup case.\n\n## Affected\n\n- `Linux >= bd27568117664b8b3e259721393df420ed51f57b < 656f35b463995bee024d948440128230aacd81e1`\n- `Linux >= bd27568117664b8b3e259721393df420ed51f57b < 3a696e84a8b1fafdd774bb30d62919faf844d9e4`\n- `Linux >= bd27568117664b8b3e259721393df420ed51f57b < 35f7914e54fe7f13654c22ee045b05e4b6d8062b`\n- `Linux >= bd27568117664b8b3e259721393df420ed51f57b < 4c759446046500a1a6785b25725725c3ff087ace`\n- `Linux >= bd27568117664b8b3e259721393df420ed51f57b < 4b9ce671960627b2505b3f64742544ae9801df97`\n- `Linux 6.2`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"twilight","depthScore":43,"depthScoreParts":{"impact":42.9,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}