{ "schemaVersion": 1, "attribution": [ { "source": "CISA Known Exploited Vulnerabilities", "url": "https://www.cisa.gov/known-exploited-vulnerabilities-catalog", "licence": "US government work" }, { "source": "GitHub Advisory Database", "url": "https://github.com/advisories", "licence": "CC BY 4.0" }, { "source": "Have I Been Pwned", "url": "https://haveibeenpwned.com/", "licence": "CC BY 4.0" }, { "source": "CVE Program (CVE records)", "url": "https://www.cve.org/Legal/TermsOfUse", "licence": "CVE Terms of Use", "notice": "Copyright © 1999-2026, The MITRE Corporation. CVE is a trademark and the CVE logo is a registered trademark of The MITRE Corporation.", "terms": "CVE Usage: MITRE hereby grants you a perpetual, worldwide, non-exclusive, no-charge, royalty-free, irrevocable copyright license to reproduce, prepare derivative works of, publicly display, publicly perform, sublicense, and distribute Common Vulnerabilities and Exposures (CVE™). Any copy you make for such purposes is authorized provided that you reproduce MITRE's copyright designation and this license in any such copy." }, { "source": "FIRST EPSS", "url": "https://www.first.org/epss/", "licence": "free to use; FIRST requests attribution" } ], "record": { "id": "CVE-2026-52977", "sourceURL": "https://www.cve.org/CVERecord?id=CVE-2026-52977", "idYear": 2026, "status": "PUBLISHED", "publishedAt": "2026-06-24T16:28:53.937Z", "updatedAt": "2026-08-19T16:28:04.076Z", "importedAt": "2026-10-24T01:58:14.884Z", "snapshot": { "id": "cve_2026-10-24_midnight_baseline", "at": "2026-10-24T00:00:00.000Z", "source": "https://github.com/CVEProject/cvelistV5/releases/tag/cve_2026-10-24_0100Z" }, "facts": { "title": "futex: Prevent lockup in requeue-PI during signal/ timeout wakeup", "summary": "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": [ { "vendor": "Linux", "product": "Linux", "defaultStatus": "unaffected", "versions": [ { "version": "07d91ef510fb16a2e0ca7453222105835b7ba3b8", "status": "affected", "versionType": "git", "lessThan": "e5dbae3572757cecc3d3ec7cf96cbcc9cd9f016c" }, { "version": "07d91ef510fb16a2e0ca7453222105835b7ba3b8", "status": "affected", "versionType": "git", "lessThan": "4e0ed44e51727d56244a822ab941efe507c47966" }, { "version": "07d91ef510fb16a2e0ca7453222105835b7ba3b8", "status": "affected", "versionType": "git", "lessThan": "e3f95b1ba242e37093305812df7fdbe7288a43ac" }, { "version": "07d91ef510fb16a2e0ca7453222105835b7ba3b8", "status": "affected", "versionType": "git", "lessThan": "0aacb6d18f76552e3e0ee25d9f40d21b3486f4cf" }, { "version": "07d91ef510fb16a2e0ca7453222105835b7ba3b8", "status": "affected", "versionType": "git", "lessThan": "69a7cfc66405aeaa2483147653d031b3592ffc9c" }, { "version": "07d91ef510fb16a2e0ca7453222105835b7ba3b8", "status": "affected", "versionType": "git", "lessThan": "0304d60abb9dcc02bc7fe6d1850f4ca206e8f1a0" }, { "version": "07d91ef510fb16a2e0ca7453222105835b7ba3b8", "status": "affected", "versionType": "git", "lessThan": "bc7304f3ae20972d11db6e0b1b541c63feda5f05" } ] }, { "vendor": "Linux", "product": "Linux", "defaultStatus": "affected", "versions": [ { "version": "5.15", "status": "affected" }, { "version": "0", "status": "unaffected", "versionType": "semver", "lessThan": "5.15" }, { "version": "5.15.216", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "5.15.*" }, { "version": "6.1.175", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "6.1.*" }, { "version": "6.6.141", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "6.6.*" }, { "version": "6.12.91", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "6.12.*" }, { "version": "6.18.33", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "6.18.*" }, { "version": "7.0.10", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "7.0.*" }, { "version": "7.1", "status": "unaffected", "versionType": "original_commit_for_fix", "lessThanOrEqual": "*" } ] } ] } } }