{"id":"CVE-2026-99169","aliases":[],"title":"futex: Fix mm reuse handling for FUT_OFF_MMSHARED","titleSource":"Linux","descriptionSource":"Linux","products":[{"vendor":"Linux","name":"Linux","platforms":[],"versions":[{"version":"222993395ed38f3751287f4bd82ef46b3eb3a66d","status":"affected","lessThan":"c17cc2027773e8e4913c5ab0fe3a489b1ed5bf81","versionType":"git"},{"version":"222993395ed38f3751287f4bd82ef46b3eb3a66d","status":"affected","lessThan":"2855ddc6844f527e375e78afb55ec2a5182f23b3","versionType":"git"},{"version":"222993395ed38f3751287f4bd82ef46b3eb3a66d","status":"affected","lessThan":"3267512ad1c2cc0c7768c5b014dc2cceb398a801","versionType":"git"}],"defaultStatus":"unaffected","source":"Linux","url":"https://www.cve.org/CVERecord?id=CVE-2026-99169"},{"vendor":"Linux","name":"Linux","platforms":[],"versions":[{"version":"5.7","status":"affected"},{"version":"0","status":"unaffected","lessThan":"5.7","versionType":"semver"},{"version":"6.18.59","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.2.13","status":"unaffected","lessThanOrEqual":"7.2.*","versionType":"semver"},{"version":"7.3","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"defaultStatus":"affected","source":"Linux","url":"https://www.cve.org/CVERecord?id=CVE-2026-99169"}],"remediation":[],"description":"In the Linux kernel, the following vulnerability has been resolved:\n\nfutex: Fix mm reuse handling for FUT_OFF_MMSHARED\n\nA FUT_OFF_MMSHARED futex is a shared futex that refers to an MM.\nIt is possible for a process to wait on a shared futex with a different MM\nbecause a FUT_OFF_INODE waiter can be requeued onto a FUT_OFF_MMSHARED\nfutex by another process.\nThis can cause FUT_OFF_MMSHARED waiters on a freed MM to consume\nwakeups intended for a newly allocated MM at the same address.\n\nFix it by keying FUT_OFF_MMSHARED using a unique 64-bit per-MM ID.\nLeave private futexes as before to avoid influencing the performance of the\nhotpath.\n\n(Multi-threaded processes typically implicitly use FUT_OFF_MMSHARED by\nsetting clear_child_tid such that it points into anonymous memory, which\ncauses mm_release() in a multi-threaded mm to perform FUTEX_WAKE.)","severity":"unknown","score":null,"published":"2026-10-28T10:35:20.170Z","modified":"2026-10-28T10:35:20.170Z","withdrawn":false,"knownExploited":false,"affected":[],"references":["https://git.kernel.org/stable/c/c17cc2027773e8e4913c5ab0fe3a489b1ed5bf81","https://git.kernel.org/stable/c/2855ddc6844f527e375e78afb55ec2a5182f23b3","https://git.kernel.org/stable/c/3267512ad1c2cc0c7768c5b014dc2cceb398a801"],"sources":[{"name":"CVE","id":"CVE-2026-99169","modified":"2026-10-28T10:35:20.170Z","url":"https://www.cve.org/CVERecord?id=CVE-2026-99169"}],"assessments":[],"sourceAffected":[],"kev":{"status":"not-listed","checkedAt":"2026-10-28T18:10:32.025Z"},"coverage":[{"source":"NVD","status":"not-checked"},{"source":"GHSA","status":"not-checked"},{"source":"EUVD","status":"not-checked"},{"source":"EPSS","status":"not-checked"}],"evidence":[]}