{"api_version":"1","generated_at":"2026-09-17T10:34:21+00:00","cve":"CVE-2026-90003","urls":{"html":"https://cve.report/CVE-2026-90003","api":"https://cve.report/api/cve/CVE-2026-90003.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-90003","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-90003"},"summary":{"title":"futex: Prevent rcuwait use-after-free during requeue PI","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nfutex: Prevent rcuwait use-after-free during requeue PI\n\nOn PREEMPT_RT, FUTEX_CMP_REQUEUE_PI can trigger a KASAN report\n(slab-out-of-bounds) in futex_requeue_pi_complete() invocation of\nrcuwait_wake_up().\n\nThe futex_q used by futex_wait_requeue_pi() is allocated on the waiter's\nstack. An early wakeup can race with a PI requeue as follows:\n\n        waiter                          requeue task\n        ------                          ------------\nfutex_wait_requeue_pi()\n  futex_do_wait()\n    schedule()\n                                       futex_requeue\n                                         futex_proxy_trylock_atomic()\n                                           futex_requeue_pi_prepare()\n                                            Q_REQUEUE_PI_NONE -> Q_REQUEUE_PI_IN_PROGRESS\n* timeout/ signal wakes waiter *\n  futex_requeue_pi_wakeup_sync()\n   Q_REQUEUE_PI_IN_PROGRESS -> Q_REQUEUE_PI_WAIT\n                                           requeue_pi_wake_futex\n                                             futex_requeue_pi_complete()\n                                               cmpxchg Q_REQUEUE_PI_WAIT -> Q_REQUEUE_PI_LOCKED\n    rcuwait_wait_event()\n      if (atomic_read(&q->requeue_state) != Q_REQUEUE_PI_WAIT)\n       break /* no schedule() */\n\n /* q.pi_state->owner == current */\n futex_private_hash_put()\n /* return from syscall */\n                                              rcuwait_wake_up(&q->requeue_wait)\n                                                /* q is gone */\n\nfutex_requeue_pi_complete() publishes Q_REQUEUE_PI_LOCKED before\ncalling rcuwait_wake_up(). The waiter observes this state in\nrcuwait_wait_event() before invoking schedule() in rcuwait_wait_event().\nHere, the waiter is free leave the syscall before requeue task can\ncomplete the wake.\n\nTo address this race skip rcuwait_wake_up() in the Q_REQUEUE_PI_LOCKED\ncase.\nThis state is only published by requeue_pi_wake_futex(), which saves\nq->task before futex_requeue_pi_complete() and wakes the waiter via\nwake_up_state().\n\nThis wake is intended to wake the waiter from its futex_do_wait() sleep.\nIf the waiter is still sleeping there, it can not get into the\nQ_REQUEUE_PI_WAIT state (and require this removed wake).\nShould the waiter be woken up from futex_do_wait() by other means (as in\nthis example) and sleep in futex_requeue_pi_wakeup_sync() then the\nwake_up_state() from requeue_pi_wake_futex() will wake it, too.\nShould the waiter task terminate before wake_up_state() had a chance to\nwake the task then the task pointer does not become invalid because the\nfutex_hash_bucket::lock is held and the task pointer is RCU protected.\n\n[bigeasy: Updated comment and commit message]","state":"PUBLISHED","assigner":"Linux","published_at":"2026-09-16 11:17:12","updated_at":"2026-09-16 15:18:24"},"problem_types":[],"metrics":[{"version":"3.1","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","type":"Secondary","score":"7.8","severity":"HIGH","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","data":{"version":"3.1","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","baseScore":7.8,"baseSeverity":"HIGH","attackVector":"LOCAL","attackComplexity":"LOW","privilegesRequired":"LOW","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"HIGH","integrityImpact":"HIGH","availabilityImpact":"HIGH"}},{"version":"3.1","source":"CNA","type":"DECLARED","score":"7.8","severity":"HIGH","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","data":{"baseScore":7.8,"baseSeverity":"HIGH","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","version":"3.1"}}],"references":[{"url":"https://git.kernel.org/stable/c/81aadbd09bf1dcd3238212f336ba699503557ae8","name":"https://git.kernel.org/stable/c/81aadbd09bf1dcd3238212f336ba699503557ae8","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/244f301759fd34b1dd0b4192ce44f8ef224e027d","name":"https://git.kernel.org/stable/c/244f301759fd34b1dd0b4192ce44f8ef224e027d","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/e4a4ccfa470f910b747b3ee8d18670ed8ac8a236","name":"https://git.kernel.org/stable/c/e4a4ccfa470f910b747b3ee8d18670ed8ac8a236","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/220ee9e04ca3b7f014c000264aa6c884f036c86e","name":"https://git.kernel.org/stable/c/220ee9e04ca3b7f014c000264aa6c884f036c86e","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/a3b8d46fe401cba3a5c46dea610e6eb3dc15370e","name":"https://git.kernel.org/stable/c/a3b8d46fe401cba3a5c46dea610e6eb3dc15370e","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/7d1559126d86be6e4f6a85663dfbfe85caa47e37","name":"https://git.kernel.org/stable/c/7d1559126d86be6e4f6a85663dfbfe85caa47e37","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-90003","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-90003","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 07d91ef510fb16a2e0ca7453222105835b7ba3b8 220ee9e04ca3b7f014c000264aa6c884f036c86e git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 07d91ef510fb16a2e0ca7453222105835b7ba3b8 81aadbd09bf1dcd3238212f336ba699503557ae8 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 07d91ef510fb16a2e0ca7453222105835b7ba3b8 244f301759fd34b1dd0b4192ce44f8ef224e027d git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 07d91ef510fb16a2e0ca7453222105835b7ba3b8 7d1559126d86be6e4f6a85663dfbfe85caa47e37 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 07d91ef510fb16a2e0ca7453222105835b7ba3b8 e4a4ccfa470f910b747b3ee8d18670ed8ac8a236 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 07d91ef510fb16a2e0ca7453222105835b7ba3b8 a3b8d46fe401cba3a5c46dea610e6eb3dc15370e git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 5.15","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 5.15 semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.1.188 6.1.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.6.157 6.6.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.12.110 6.12.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.18.51 6.18.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.2.5 7.2.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.3-rc2 * original_commit_for_fix","platforms":[]}],"timeline":[],"solutions":[],"workarounds":[],"exploits":[],"credits":[],"nvd_cpes":[],"vendor_comments":[],"enrichments":{"kev":null,"epss":null,"legacy_qids":[]},"source_records":{"cve_program":{"containers":{"cna":{"affected":[{"defaultStatus":"unaffected","product":"Linux","programFiles":["kernel/futex/requeue.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"lessThan":"220ee9e04ca3b7f014c000264aa6c884f036c86e","status":"affected","version":"07d91ef510fb16a2e0ca7453222105835b7ba3b8","versionType":"git"},{"lessThan":"81aadbd09bf1dcd3238212f336ba699503557ae8","status":"affected","version":"07d91ef510fb16a2e0ca7453222105835b7ba3b8","versionType":"git"},{"lessThan":"244f301759fd34b1dd0b4192ce44f8ef224e027d","status":"affected","version":"07d91ef510fb16a2e0ca7453222105835b7ba3b8","versionType":"git"},{"lessThan":"7d1559126d86be6e4f6a85663dfbfe85caa47e37","status":"affected","version":"07d91ef510fb16a2e0ca7453222105835b7ba3b8","versionType":"git"},{"lessThan":"e4a4ccfa470f910b747b3ee8d18670ed8ac8a236","status":"affected","version":"07d91ef510fb16a2e0ca7453222105835b7ba3b8","versionType":"git"},{"lessThan":"a3b8d46fe401cba3a5c46dea610e6eb3dc15370e","status":"affected","version":"07d91ef510fb16a2e0ca7453222105835b7ba3b8","versionType":"git"}]},{"defaultStatus":"affected","product":"Linux","programFiles":["kernel/futex/requeue.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"status":"affected","version":"5.15"},{"lessThan":"5.15","status":"unaffected","version":"0","versionType":"semver"},{"lessThanOrEqual":"6.1.*","status":"unaffected","version":"6.1.188","versionType":"semver"},{"lessThanOrEqual":"6.6.*","status":"unaffected","version":"6.6.157","versionType":"semver"},{"lessThanOrEqual":"6.12.*","status":"unaffected","version":"6.12.110","versionType":"semver"},{"lessThanOrEqual":"6.18.*","status":"unaffected","version":"6.18.51","versionType":"semver"},{"lessThanOrEqual":"7.2.*","status":"unaffected","version":"7.2.5","versionType":"semver"},{"lessThanOrEqual":"*","status":"unaffected","version":"7.3-rc2","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"cpeMatch":[{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.1.188","versionStartIncluding":"5.15","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.6.157","versionStartIncluding":"5.15","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.12.110","versionStartIncluding":"5.15","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.18.51","versionStartIncluding":"5.15","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.2.5","versionStartIncluding":"5.15","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.3-rc2","versionStartIncluding":"5.15","vulnerable":true}],"negate":false,"operator":"OR"}]}],"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nfutex: Prevent rcuwait use-after-free during requeue PI\n\nOn PREEMPT_RT, FUTEX_CMP_REQUEUE_PI can trigger a KASAN report\n(slab-out-of-bounds) in futex_requeue_pi_complete() invocation of\nrcuwait_wake_up().\n\nThe futex_q used by futex_wait_requeue_pi() is allocated on the waiter's\nstack. An early wakeup can race with a PI requeue as follows:\n\n        waiter                          requeue task\n        ------                          ------------\nfutex_wait_requeue_pi()\n  futex_do_wait()\n    schedule()\n                                       futex_requeue\n                                         futex_proxy_trylock_atomic()\n                                           futex_requeue_pi_prepare()\n                                            Q_REQUEUE_PI_NONE -> Q_REQUEUE_PI_IN_PROGRESS\n* timeout/ signal wakes waiter *\n  futex_requeue_pi_wakeup_sync()\n   Q_REQUEUE_PI_IN_PROGRESS -> Q_REQUEUE_PI_WAIT\n                                           requeue_pi_wake_futex\n                                             futex_requeue_pi_complete()\n                                               cmpxchg Q_REQUEUE_PI_WAIT -> Q_REQUEUE_PI_LOCKED\n    rcuwait_wait_event()\n      if (atomic_read(&q->requeue_state) != Q_REQUEUE_PI_WAIT)\n       break /* no schedule() */\n\n /* q.pi_state->owner == current */\n futex_private_hash_put()\n /* return from syscall */\n                                              rcuwait_wake_up(&q->requeue_wait)\n                                                /* q is gone */\n\nfutex_requeue_pi_complete() publishes Q_REQUEUE_PI_LOCKED before\ncalling rcuwait_wake_up(). The waiter observes this state in\nrcuwait_wait_event() before invoking schedule() in rcuwait_wait_event().\nHere, the waiter is free leave the syscall before requeue task can\ncomplete the wake.\n\nTo address this race skip rcuwait_wake_up() in the Q_REQUEUE_PI_LOCKED\ncase.\nThis state is only published by requeue_pi_wake_futex(), which saves\nq->task before futex_requeue_pi_complete() and wakes the waiter via\nwake_up_state().\n\nThis wake is intended to wake the waiter from its futex_do_wait() sleep.\nIf the waiter is still sleeping there, it can not get into the\nQ_REQUEUE_PI_WAIT state (and require this removed wake).\nShould the waiter be woken up from futex_do_wait() by other means (as in\nthis example) and sleep in futex_requeue_pi_wakeup_sync() then the\nwake_up_state() from requeue_pi_wake_futex() will wake it, too.\nShould the waiter task terminate before wake_up_state() had a chance to\nwake the task then the task pointer does not become invalid because the\nfutex_hash_bucket::lock is held and the task pointer is RCU protected.\n\n[bigeasy: Updated comment and commit message]"}],"metrics":[{"cvssV3_1":{"baseScore":7.8,"baseSeverity":"HIGH","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","version":"3.1"},"scenarios":[{"lang":"en","value":"AV:L - The bug is reached only through the local futex(2) syscalls FUTEX_WAIT_REQUEUE_PI and FUTEX_CMP_REQUEUE_PI into kernel/futex/requeue.c; there is no network, Bluetooth, or physical-device path.\nAC:L - The attacker controls both sides of the race: a waiter thread using FUTEX_WAIT_REQUEUE_PI with an attacker-chosen timeout or signal, and a concurrent FUTEX_CMP_REQUEUE_PI from another thread, and can retry with CPU pinning until the waiter returns before rcuwait_wake_up() on PREEMPT_RT.\nPR:L - Any unprivileged local user can invoke futex() with FUTEX_WAIT_REQUEUE_PI and FUTEX_CMP_REQUEUE_PI; do_futex() and futex_requeue() perform no capability or credential checks, CONFIG_FUTEX_PI is default-y, and the path is reachable from containers without elevated privileges.\nUI:N - The attacker's own threads perform the wait, timeout or signal, and PI requeue; no victim action such as mounting a filesystem or opening a file is required.\nS:U - The use-after-free corrupts kernel memory (the waiter's stack-allocated futex_q and a type-confused task_struct) within the same kernel security authority; this is a standard local privilege-escalation issue, not a VM, IOMMU, or hypervisor escape.\nC:H - This is a use-after-free of the waiter's stack-allocated futex_q.requeue_wait; rcuwait_wake_up() reads a stale, attacker-refilled task_struct pointer and dereferences it in try_to_wake_up(), enabling arbitrary kernel-memory disclosure.\nI:H - The stale futex_q lives on the attacker's own kernel stack, which a following syscall can refill with controlled bytes, so rcuwait_wake_up() passes an attacker-chosen pointer into try_to_wake_up(), which writes task state and makes indirect scheduler calls, enabling privilege escalation.\nA:H - In the unexploited case, rcuwait_wake_up() dereferences a wild pointer from reused stack memory and causes a kernel oops or panic; any use-after-free of this kind is a High availability impact."}]}],"providerMetadata":{"dateUpdated":"2026-09-16T14:41:20.519Z","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux"},"references":[{"url":"https://git.kernel.org/stable/c/220ee9e04ca3b7f014c000264aa6c884f036c86e"},{"url":"https://git.kernel.org/stable/c/81aadbd09bf1dcd3238212f336ba699503557ae8"},{"url":"https://git.kernel.org/stable/c/244f301759fd34b1dd0b4192ce44f8ef224e027d"},{"url":"https://git.kernel.org/stable/c/7d1559126d86be6e4f6a85663dfbfe85caa47e37"},{"url":"https://git.kernel.org/stable/c/e4a4ccfa470f910b747b3ee8d18670ed8ac8a236"},{"url":"https://git.kernel.org/stable/c/a3b8d46fe401cba3a5c46dea610e6eb3dc15370e"}],"title":"futex: Prevent rcuwait use-after-free during requeue PI","x_generator":{"engine":"bippy-1.2.0"}}},"cveMetadata":{"assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","assignerShortName":"Linux","cveId":"CVE-2026-90003","datePublished":"2026-09-16T10:33:13.420Z","dateReserved":"2026-09-11T19:38:34.780Z","dateUpdated":"2026-09-16T14:41:20.519Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-09-16 11:17:12","lastModifiedDate":"2026-09-16 15:18:24","problem_types":[],"metrics":{"cvssMetricV31":[{"source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","type":"Secondary","cvssData":{"version":"3.1","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","baseScore":7.8,"baseSeverity":"HIGH","attackVector":"LOCAL","attackComplexity":"LOW","privilegesRequired":"LOW","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"HIGH","integrityImpact":"HIGH","availabilityImpact":"HIGH"},"exploitabilityScore":1.8,"impactScore":5.9}]},"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"90003","Ordinal":"1","Title":"futex: Prevent rcuwait use-after-free during requeue PI","CVE":"CVE-2026-90003","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"90003","Ordinal":"1","NoteData":"In the Linux kernel, the following vulnerability has been resolved:\n\nfutex: Prevent rcuwait use-after-free during requeue PI\n\nOn PREEMPT_RT, FUTEX_CMP_REQUEUE_PI can trigger a KASAN report\n(slab-out-of-bounds) in futex_requeue_pi_complete() invocation of\nrcuwait_wake_up().\n\nThe futex_q used by futex_wait_requeue_pi() is allocated on the waiter's\nstack. An early wakeup can race with a PI requeue as follows:\n\n        waiter                          requeue task\n        ------                          ------------\nfutex_wait_requeue_pi()\n  futex_do_wait()\n    schedule()\n                                       futex_requeue\n                                         futex_proxy_trylock_atomic()\n                                           futex_requeue_pi_prepare()\n                                            Q_REQUEUE_PI_NONE -> Q_REQUEUE_PI_IN_PROGRESS\n* timeout/ signal wakes waiter *\n  futex_requeue_pi_wakeup_sync()\n   Q_REQUEUE_PI_IN_PROGRESS -> Q_REQUEUE_PI_WAIT\n                                           requeue_pi_wake_futex\n                                             futex_requeue_pi_complete()\n                                               cmpxchg Q_REQUEUE_PI_WAIT -> Q_REQUEUE_PI_LOCKED\n    rcuwait_wait_event()\n      if (atomic_read(&q->requeue_state) != Q_REQUEUE_PI_WAIT)\n       break /* no schedule() */\n\n /* q.pi_state->owner == current */\n futex_private_hash_put()\n /* return from syscall */\n                                              rcuwait_wake_up(&q->requeue_wait)\n                                                /* q is gone */\n\nfutex_requeue_pi_complete() publishes Q_REQUEUE_PI_LOCKED before\ncalling rcuwait_wake_up(). The waiter observes this state in\nrcuwait_wait_event() before invoking schedule() in rcuwait_wait_event().\nHere, the waiter is free leave the syscall before requeue task can\ncomplete the wake.\n\nTo address this race skip rcuwait_wake_up() in the Q_REQUEUE_PI_LOCKED\ncase.\nThis state is only published by requeue_pi_wake_futex(), which saves\nq->task before futex_requeue_pi_complete() and wakes the waiter via\nwake_up_state().\n\nThis wake is intended to wake the waiter from its futex_do_wait() sleep.\nIf the waiter is still sleeping there, it can not get into the\nQ_REQUEUE_PI_WAIT state (and require this removed wake).\nShould the waiter be woken up from futex_do_wait() by other means (as in\nthis example) and sleep in futex_requeue_pi_wakeup_sync() then the\nwake_up_state() from requeue_pi_wake_futex() will wake it, too.\nShould the waiter task terminate before wake_up_state() had a chance to\nwake the task then the task pointer does not become invalid because the\nfutex_hash_bucket::lock is held and the task pointer is RCU protected.\n\n[bigeasy: Updated comment and commit message]","Type":"Description","Title":"futex: Prevent rcuwait use-after-free during requeue PI"}]}}}