{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-52977", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-06-09T07:44:35.376Z", "datePublished": "2026-06-24T16:28:53.937Z", "dateUpdated": "2026-08-19T16:28:04.076Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-19T16:28:04.076Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nfutex: Prevent lockup in requeue-PI during signal/ timeout wakeup\n\nDuring wait-requeue-pi (task A) and requeue-PI (task B) the following\nrace can happen:\n\n Task A Task B\n futex_wait_requeue_pi()\n futex_setup_timer()\n futex_do_wait()\n futex_requeue()\n CLASS(hb, hb1)(&key1);\n CLASS(hb, hb2)(&key2);\n *timeout*\n futex_requeue_pi_wakeup_sync()\n requeue_state = Q_REQUEUE_PI_IGNORE\n\n *blocks on hb->lock*\n\n futex_proxy_trylock_atomic()\n futex_requeue_pi_prepare()\n Q_REQUEUE_PI_IGNORE => -EAGAIN\n double_unlock_hb(hb1, hb2)\n *retry*\n\nTask B acquires both hb locks and attempts to acquire the PI-lock of the\ntop most waiter (task B). Task A is leaving early due to a signal/\ntimeout and started removing itself from the queue. It updates its\nrequeue_state but can not remove it from the list because this requires\nthe hb lock which is owned by task B.\n\nUsually task A is able to swoop the lock after task B unlocked it.\nHowever if task B is of higher priority then task A may not be able to\nwake up in time and acquire the lock before task B gets it again.\nEspecially on a UP system where A is never scheduled.\n\nAs a result task A blocks on the lock and task B busy loops, trying to\nmake progress but live locks the system instead. Tragic.\n\nThis can be fixed by removing the top most waiter from the list in this\ncase. This allows task B to grab the next top waiter (if any) in the\nnext iteration and make progress.\n\nRemove the top most waiter if futex_requeue_pi_prepare() fails.\nLet the waiter conditionally remove itself from the list in\nhandle_early_requeue_pi_wakeup()." } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "kernel/futex/requeue.c" ], "versions": [ { "version": "07d91ef510fb16a2e0ca7453222105835b7ba3b8", "lessThan": "e5dbae3572757cecc3d3ec7cf96cbcc9cd9f016c", "status": "affected", "versionType": "git" }, { "version": "07d91ef510fb16a2e0ca7453222105835b7ba3b8", "lessThan": "4e0ed44e51727d56244a822ab941efe507c47966", "status": "affected", "versionType": "git" }, { "version": "07d91ef510fb16a2e0ca7453222105835b7ba3b8", "lessThan": "e3f95b1ba242e37093305812df7fdbe7288a43ac", "status": "affected", "versionType": "git" }, { "version": "07d91ef510fb16a2e0ca7453222105835b7ba3b8", "lessThan": "0aacb6d18f76552e3e0ee25d9f40d21b3486f4cf", "status": "affected", "versionType": "git" }, { "version": "07d91ef510fb16a2e0ca7453222105835b7ba3b8", "lessThan": "69a7cfc66405aeaa2483147653d031b3592ffc9c", "status": "affected", "versionType": "git" }, { "version": "07d91ef510fb16a2e0ca7453222105835b7ba3b8", "lessThan": "0304d60abb9dcc02bc7fe6d1850f4ca206e8f1a0", "status": "affected", "versionType": "git" }, { "version": "07d91ef510fb16a2e0ca7453222105835b7ba3b8", "lessThan": "bc7304f3ae20972d11db6e0b1b541c63feda5f05", "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/requeue.c" ], "versions": [ { "version": "5.15", "status": "affected" }, { "version": "0", "lessThan": "5.15", "status": "unaffected", "versionType": "semver" }, { "version": "5.15.216", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.175", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.141", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.91", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.33", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.0.10", "lessThanOrEqual": "7.0.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.1", "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": "5.15", "versionEndExcluding": "5.15.216" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.15", "versionEndExcluding": "6.1.175" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.15", "versionEndExcluding": "6.6.141" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.15", "versionEndExcluding": "6.12.91" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.15", "versionEndExcluding": "6.18.33" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.15", "versionEndExcluding": "7.0.10" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.15", "versionEndExcluding": "7.1" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/e5dbae3572757cecc3d3ec7cf96cbcc9cd9f016c" }, { "url": "https://git.kernel.org/stable/c/4e0ed44e51727d56244a822ab941efe507c47966" }, { "url": "https://git.kernel.org/stable/c/e3f95b1ba242e37093305812df7fdbe7288a43ac" }, { "url": "https://git.kernel.org/stable/c/0aacb6d18f76552e3e0ee25d9f40d21b3486f4cf" }, { "url": "https://git.kernel.org/stable/c/69a7cfc66405aeaa2483147653d031b3592ffc9c" }, { "url": "https://git.kernel.org/stable/c/0304d60abb9dcc02bc7fe6d1850f4ca206e8f1a0" }, { "url": "https://git.kernel.org/stable/c/bc7304f3ae20972d11db6e0b1b541c63feda5f05" } ], "title": "futex: Prevent lockup in requeue-PI during signal/ timeout wakeup", "x_generator": { "engine": "bippy-1.2.0" } } } }