{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2025-21895","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","state":"PUBLISHED","assignerShortName":"Linux","dateReserved":"2024-12-29T08:45:45.783Z","datePublished":"2025-04-01T15:26:48.607Z","dateUpdated":"2026-05-11T21:08:35.977Z"},"containers":{"cna":{"providerMetadata":{"orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux","dateUpdated":"2026-05-11T21:08:35.977Z"},"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nperf/core: Order the PMU list to fix warning about unordered pmu_ctx_list\n\nSyskaller triggers a warning due to prev_epc->pmu != next_epc->pmu in\nperf_event_swap_task_ctx_data(). vmcore shows that two lists have the same\nperf_event_pmu_context, but not in the same order.\n\nThe problem is that the order of pmu_ctx_list for the parent is impacted by\nthe time when an event/PMU is added. While the order for a child is\nimpacted by the event order in the pinned_groups and flexible_groups. So\nthe order of pmu_ctx_list in the parent and child may be different.\n\nTo fix this problem, insert the perf_event_pmu_context to its proper place\nafter iteration of the pmu_ctx_list.\n\nThe follow testcase can trigger above warning:\n\n # perf record -e cycles --call-graph lbr -- taskset -c 3 ./a.out &\n # perf stat -e cpu-clock,cs -p xxx // xxx is the pid of a.out\n\n test.c\n\n void main() {\n        int count = 0;\n        pid_t pid;\n\n        printf(\"%d running\\n\", getpid());\n        sleep(30);\n        printf(\"running\\n\");\n\n        pid = fork();\n        if (pid == -1) {\n                printf(\"fork error\\n\");\n                return;\n        }\n        if (pid == 0) {\n                while (1) {\n                        count++;\n                }\n        } else {\n                while (1) {\n                        count++;\n                }\n        }\n }\n\nThe testcase first opens an LBR event, so it will allocate task_ctx_data,\nand then open tracepoint and software events, so the parent context will\nhave 3 different perf_event_pmu_contexts. On inheritance, child ctx will\ninsert the perf_event_pmu_context in another order and the warning will\ntrigger.\n\n[ mingo: Tidied up the changelog. ]"}],"affected":[{"product":"Linux","vendor":"Linux","defaultStatus":"unaffected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["kernel/events/core.c"],"versions":[{"version":"bd27568117664b8b3e259721393df420ed51f57b","lessThan":"f0c3971405cef6892844016aa710121a02da3a23","status":"affected","versionType":"git"},{"version":"bd27568117664b8b3e259721393df420ed51f57b","lessThan":"7d582eb6e4e100959ba07083d7563453c8c2a343","status":"affected","versionType":"git"},{"version":"bd27568117664b8b3e259721393df420ed51f57b","lessThan":"3e812a70732d84b7873cea61a7f6349b9a9dcbf5","status":"affected","versionType":"git"},{"version":"bd27568117664b8b3e259721393df420ed51f57b","lessThan":"2016066c66192a99d9e0ebf433789c490a6785a2","status":"affected","versionType":"git"}]},{"product":"Linux","vendor":"Linux","defaultStatus":"affected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["kernel/events/core.c"],"versions":[{"version":"6.2","status":"affected"},{"version":"0","lessThan":"6.2","status":"unaffected","versionType":"semver"},{"version":"6.6.81","lessThanOrEqual":"6.6.*","status":"unaffected","versionType":"semver"},{"version":"6.12.18","lessThanOrEqual":"6.12.*","status":"unaffected","versionType":"semver"},{"version":"6.13.6","lessThanOrEqual":"6.13.*","status":"unaffected","versionType":"semver"},{"version":"6.14","lessThanOrEqual":"*","status":"unaffected","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.2","versionEndExcluding":"6.6.81"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.2","versionEndExcluding":"6.12.18"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.2","versionEndExcluding":"6.13.6"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.2","versionEndExcluding":"6.14"}]}]}],"references":[{"url":"https://git.kernel.org/stable/c/f0c3971405cef6892844016aa710121a02da3a23"},{"url":"https://git.kernel.org/stable/c/7d582eb6e4e100959ba07083d7563453c8c2a343"},{"url":"https://git.kernel.org/stable/c/3e812a70732d84b7873cea61a7f6349b9a9dcbf5"},{"url":"https://git.kernel.org/stable/c/2016066c66192a99d9e0ebf433789c490a6785a2"}],"title":"perf/core: Order the PMU list to fix warning about unordered pmu_ctx_list","x_generator":{"engine":"bippy-1.2.0"}}}}