{"id":"CVE-2026-74637","revision":"53f1dd8d0bd849e0ae7f76450dd3d68b","records":[{"revision":"53f1dd8d0bd849e0ae7f76450dd3d68b","observedAt":"2026-10-23T15:48:27.903+00:00","statement":{"source":"cve-program","id":"CVE-2026-74637","aliases":[],"title":"perf/core: Fix group leader use-after-free after sibling detach","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nperf/core: Fix group leader use-after-free after sibling detach\n\nperf_group_detach() handles leader and sibling detach differently. When the\ngroup leader is detached, all siblings are promoted to singleton events and\ntheir group_leader pointer is reset to themselves. When a sibling is\ndetached, it is removed from the leader's sibling_list, but its\ngroup_leader pointer is left pointing at the old leader.\n\nThat is harmless when the sibling is being closed and freed immediately, as\nin the DETACH_DEAD path. It is not safe when the sibling is detached but\nkept alive, such as during CPU hotplug with DETACH_GROUP. In that case the\nsibling is removed from the context, while its file descriptor can still\nkeep it alive.\n\nA typical failing sequence is:\n\n - A group contains leader L and sibling S.\n - CPU hot-unplug detaches S with DETACH_GROUP, removing it from\n L->sibling_list but leaving S->group_leader == L.\n - L is later closed and freed.\n - A PERF_IOC_FLAG_GROUP ioctl on S follows S->group_leader and\n dereferences the freed leader.\n\nThis was reproduced by running the perf event fuzzer, CPU hotplug, and a\nstress workload concurrently:\n\n Unable to handle kernel paging request at virtual address 006b6b6b6b6b6cdb\n CPU: 2 PID: 12489 Comm: perf_fuzzer 6.18.7 PREEMPT\n pc : perf_ioctl+0x34c/0xc68\n x20: ffffff89a3fa2c70 x8 : 6b6b6b6b6b6b6b6b\n Code: 943c4a0e 340047a0 f9404a94 f9411e88 (f940b908)\n Call trace:\n perf_ioctl+0x34c/0xc68 (P)\n __arm64_sys_ioctl+0xa0/0xf4\n invoke_syscall+0x58/0xe4\n el0_svc_common+0xa8/0xdc\n do_el0_svc+0x1c/0x28\n el0_svc+0x40/0xc0\n el0t_64_sync_handler+0x68/0xdc\n el0t_64_sync+0x1c4/0x1c8\n\nThe fault happened in perf_ioctl(), where perf_event_for_each() follows\nthe stale group_leader pointer and perf_event_for_each_child() then\ndereferences the freed leader's context.\n\nFix the use-after-free by promoting the detached sibling to a singleton.\nAlso fix __event_disable() cgroup accounting and event state change.","state":0,"publishedAt":"2026-08-22T15:32:16.755+00:00","modifiedAt":"2026-10-16T19:06:04.262+00:00","affected":[{"ecosystem":"Vendor product","name":"Linux","ranges":[],"versions":[],"rawVersionEvidence":"{\n \"product\": \"Linux\",\n \"vendor\": \"Linux\",\n \"defaultStatus\": \"unaffected\",\n \"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\n \"programFiles\": [\n \"kernel/events/core.c\"\n ],\n \"versions\": [\n {\n \"version\": \"8a49542c0554af7d0073aac0ee73ee65b807ef34\",\n \"lessThan\": \"8f867c0e8da4c2303d91adf45acb6b1820966c27\",\n \"status\": \"affected\",\n \"versionType\": \"git\"\n },\n {\n \"version\": \"8a49542c0554af7d0073aac0ee73ee65b807ef34\",\n \"lessThan\": \"8e92e03984364d93e0d5b0acd81c95eca773f034\",\n \"status\": \"affected\",\n \"versionType\": \"git\"\n },\n {\n \"version\": \"8a49542c0554af7d0073aac0ee73ee65b807ef34\",\n \"lessThan\": \"f8a07021679aadfb6d63b209207ccc41f26982d1\",\n \"status\": \"affected\",\n \"versionType\": \"git\"\n },\n {\n \"version\": \"8a49542c0554af7d0073aac0ee73ee65b807ef34\",\n \"lessThan\": \"80c6054a4c40a0ffad82acef9f9a0dee108d152a\",\n \"status\": \"affected\",\n \"versionType\": \"git\"\n },\n {\n \"version\": \"8a49542c0554af7d0073aac0ee73ee65b807ef34\",\n \"lessThan\": \"b42948f9e0d1ea4dbd5742ce1dfc7688de5d4a35\",\n \"status\": \"affected\",\n \"versionType\": \"git\"\n },\n {\n \"version\": \"8a49542c0554af7d0073aac0ee73ee65b807ef34\",\n \"lessThan\": \"a979a642402d0b1f856c7a729b4cb2d92de4cf2f\",\n \"status\": \"affected\",\n \"versionType\": \"git\"\n },\n {\n \"version\": \"8a49542c0554af7d0073aac0ee73ee65b807ef34\",\n \"lessThan\": \"1e7abfeb23c12bf46f6457e4a3e1a1a300d50619\",\n \"status\": \"affected\",\n \"versionType\": \"git\"\n },\n {\n \"version\": \"8a49542c0554af7d0073aac0ee73ee65b807ef34\",\n \"lessThan\": \"42c5ca1f0a288a52878bd72a5595b08261057438\",\n \"status\": \"affected\",\n \"versionType\": \"git\"\n },\n {\n \"version\": \"e732ebc42aea321ee84514330eb3a675307fcc83\",\n \"status\": \"affected\",\n \"versionType\": \"git\"\n },\n {\n \"version\": \"2.6.34.14\",\n \"lessThan\": \"2.6.35\",\n \"status\": \"affected\",\n \"versionType\": \"semver\"\n }\n ]\n }"},{"ecosystem":"Vendor product","name":"Linux","ranges":[],"versions":[],"rawVersionEvidence":"{\n \"product\": \"Linux\",\n \"vendor\": \"Linux\",\n \"defaultStatus\": \"affected\",\n \"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\n \"programFiles\": [\n \"kernel/events/core.c\"\n ],\n \"versions\": [\n {\n \"version\": \"2.6.35\",\n \"status\": \"affected\"\n },\n {\n \"version\": \"0\",\n \"lessThan\": \"2.6.35\",\n \"status\": \"unaffected\",\n \"versionType\": \"semver\"\n },\n {\n \"version\": \"5.10.267\",\n \"lessThanOrEqual\": \"5.10.*\",\n \"status\": \"unaffected\",\n \"versionType\": \"semver\"\n },\n {\n \"version\": \"5.15.218\",\n \"lessThanOrEqual\": \"5.15.*\",\n \"status\": \"unaffected\",\n \"versionType\": \"semver\"\n },\n {\n \"version\": \"6.1.185\",\n \"lessThanOrEqual\": \"6.1.*\",\n \"status\": \"unaffected\",\n \"versionType\": \"semver\"\n },\n {\n \"version\": \"6.6.154\",\n \"lessThanOrEqual\": \"6.6.*\",\n \"status\": \"unaffected\",\n \"versionType\": \"semver\"\n },\n {\n \"version\": \"6.12.105\",\n \"lessThanOrEqual\": \"6.12.*\",\n \"status\": \"unaffected\",\n \"versionType\": \"semver\"\n },\n {\n \"version\": \"6.18.45\",\n \"lessThanOrEqual\": \"6.18.*\",\n \"status\": \"unaffected\",\n \"versionType\": \"semver\"\n },\n {\n \"version\": \"7.1.9\",\n \"lessThanOrEqual\": \"7.1.*\",\n \"status\": \"unaffected\",\n \"versionType\": \"semver\"\n },\n {\n \"version\": \"7.2\",\n \"lessThanOrEqual\": \"*\",\n \"status\": \"unaffected\",\n \"versionType\": \"original_commit_for_fix\"\n }\n ]\n }"}],"metrics":[{"system":"CVSS 3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","score":7.8,"severity":"HIGH"}],"references":["https://git.kernel.org/stable/c/8f867c0e8da4c2303d91adf45acb6b1820966c27","https://git.kernel.org/stable/c/8e92e03984364d93e0d5b0acd81c95eca773f034","https://git.kernel.org/stable/c/f8a07021679aadfb6d63b209207ccc41f26982d1","https://git.kernel.org/stable/c/80c6054a4c40a0ffad82acef9f9a0dee108d152a","https://git.kernel.org/stable/c/b42948f9e0d1ea4dbd5742ce1dfc7688de5d4a35","https://git.kernel.org/stable/c/a979a642402d0b1f856c7a729b4cb2d92de4cf2f","https://git.kernel.org/stable/c/1e7abfeb23c12bf46f6457e4a3e1a1a300d50619","https://git.kernel.org/stable/c/42c5ca1f0a288a52878bd72a5595b08261057438"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-74637","license":"CVE Program Terms of Use","key":"cve-program:CVE-2026-74637","identifiers":["CVE-2026-74637"]},"retained":false,"historicalAffected":[]}],"coverage":[]}