{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-80776","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","state":"PUBLISHED","assignerShortName":"Linux","dateReserved":"2026-08-26T14:34:25.792Z","datePublished":"2026-09-04T15:12:48.314Z","dateUpdated":"2026-09-04T15:12:48.314Z"},"containers":{"cna":{"providerMetadata":{"orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux","dateUpdated":"2026-09-04T15:12:48.314Z"},"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nfutex: Fix race in futex_pivot_pending() during private hash resize\n\nA task performing a custom private hash resize can remain blocked in\nuninterruptible sleep indefinitely.  The hung-task detector reports:\n\n  INFO: task futex-resizer:314 blocked for more than 10 seconds.\n  task:futex-resizer state:D stack:14824 pid:314 tgid:312 ppid:311\n\n  Call Trace:\n   __schedule+0x521/0xf30\n   schedule+0x22/0xa0\n   futex_hash_allocate+0x3db/0x490\n   __do_sys_prctl+0x6f5/0xbd0\n   do_syscall_64+0xf9/0x530\n   entry_SYSCALL_64_after_hwframe+0x77/0x7f\n\n  Kernel panic - not syncing: hung_task: blocked tasks\n\nfutex_pivot_pending() allows the resize request to continue when\neither no replacement hash is pending (hash_new == NULL) or the current\nhash reference count has reached zero.\n\nAfter the final-reference wake, another futex task can complete the\npivot between the two observations:\n\n  T1                                  T2\n\n  futex_hash_allocate()\n    wait_var_event(mm, ...)\n      futex_pivot_pending(mm)\n        hash_new != NULL\n                                      futex_hash()\n                                        futex_ref_get(old) -> false\n                                        futex_pivot_hash(mm)\n                                          hash_new = NULL\n                                          __futex_pivot_hash(mm, new)\n                                            rcu_assign_pointer(hash, new)\n        fph = rcu_dereference(hash) /* new */\n        futex_ref_is_dead(fph) -> false\n      schedule()\n\nThe pivot changes the state from hash_new != NULL with a dead current\nhash to hash_new == NULL with a live current hash.  Because\nfutex_pivot_pending() reads hash_new and hash without serialization,\nthe resize task can observe hash_new in the pre-pivot state and hash in\nthe post-pivot state, causing futex_pivot_pending() to return false even\nthough the pivot has completed.  The task then goes to sleep after the\nwakeup has already been consumed.\n\nSerialize state reads in futex_pivot_pending() using futex_mm_phash::lock.\nThis guarantees that futex_pivot_pending() observes hash_new and hash\natomically, eliminating the race condition."}],"affected":[{"product":"Linux","vendor":"Linux","defaultStatus":"unaffected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["kernel/futex/core.c"],"versions":[{"version":"bd54df5ea7cadac520e346d5f0fe5d58e635b6ba","lessThan":"4a7e941ca29a608c6244cbd028d3599ecaef7207","status":"affected","versionType":"git"},{"version":"bd54df5ea7cadac520e346d5f0fe5d58e635b6ba","lessThan":"19b4be0717fa83265d66aea836b7022d898422cf","status":"affected","versionType":"git"},{"version":"bd54df5ea7cadac520e346d5f0fe5d58e635b6ba","lessThan":"8e7ff730dd96519a333d1570edf1c3fabb6d3629","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/futex/core.c"],"versions":[{"version":"6.16","status":"affected"},{"version":"0","lessThan":"6.16","status":"unaffected","versionType":"semver"},{"version":"6.18.46","lessThanOrEqual":"6.18.*","status":"unaffected","versionType":"semver"},{"version":"7.1.11","lessThanOrEqual":"7.1.*","status":"unaffected","versionType":"semver"},{"version":"7.2","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":"6.16","versionEndExcluding":"6.18.46"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.16","versionEndExcluding":"7.1.11"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.16","versionEndExcluding":"7.2"}]}]}],"references":[{"url":"https://git.kernel.org/stable/c/4a7e941ca29a608c6244cbd028d3599ecaef7207"},{"url":"https://git.kernel.org/stable/c/19b4be0717fa83265d66aea836b7022d898422cf"},{"url":"https://git.kernel.org/stable/c/8e7ff730dd96519a333d1570edf1c3fabb6d3629"}],"title":"futex: Fix race in futex_pivot_pending() during private hash resize","x_generator":{"engine":"bippy-1.2.0"}}}}