CVE-2021-47069

{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2021-47069", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2024-02-29T22:33:44.296Z", "datePublished": "2024-03-01T21:15:08.598Z", "dateUpdated": "2026-08-05T08:45:50.647Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T08:45:50.647Z"}, "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nipc/mqueue, msg, sem: avoid relying on a stack reference past its expiry\n\ndo_mq_timedreceive calls wq_sleep with a stack local address. The\nsender (do_mq_timedsend) uses this address to later call pipelined_send.\n\nThis leads to a very hard to trigger race where a do_mq_timedreceive\ncall might return and leave do_mq_timedsend to rely on an invalid\naddress, causing the following crash:\n\n RIP: 0010:wake_q_add_safe+0x13/0x60\n Call Trace:\n __x64_sys_mq_timedsend+0x2a9/0x490\n do_syscall_64+0x80/0x680\n entry_SYSCALL_64_after_hwframe+0x44/0xa9\n RIP: 0033:0x7f5928e40343\n\nThe race occurs as:\n\n1. do_mq_timedreceive calls wq_sleep with the address of `struct\n ext_wait_queue` on function stack (aliased as `ewq_addr` here) - it\n holds a valid `struct ext_wait_queue *` as long as the stack has not\n been overwritten.\n\n2. `ewq_addr` gets added to info->e_wait_q[RECV].list in wq_add, and\n do_mq_timedsend receives it via wq_get_first_waiter(info, RECV) to call\n __pipelined_op.\n\n3. Sender calls __pipelined_op::smp_store_release(&this->state,\n STATE_READY). Here is where the race window begins. (`this` is\n `ewq_addr`.)\n\n4. If the receiver wakes up now in do_mq_timedreceive::wq_sleep, it\n will see `state == STATE_READY` and break.\n\n5. do_mq_timedreceive returns, and `ewq_addr` is no longer guaranteed\n to be a `struct ext_wait_queue *` since it was on do_mq_timedreceive's\n stack. (Although the address may not get overwritten until another\n function happens to touch it, which means it can persist around for an\n indefinite time.)\n\n6. do_mq_timedsend::__pipelined_op() still believes `ewq_addr` is a\n `struct ext_wait_queue *`, and uses it to find a task_struct to pass to\n the wake_q_add_safe call. In the lucky case where nothing has\n overwritten `ewq_addr` yet, `ewq_addr->task` is the right task_struct.\n In the unlucky case, __pipelined_op::wake_q_add_safe gets handed a\n bogus address as the receiver's task_struct causing the crash.\n\ndo_mq_timedsend::__pipelined_op() should not dereference `this` after\nsetting STATE_READY, as the receiver counterpart is now free to return.\nChange __pipelined_op to call wake_q_add_safe on the receiver's\ntask_struct returned by get_task_struct, instead of dereferencing `this`\nwhich sits on the receiver's stack.\n\nAs Manfred pointed out, the race potentially also exists in\nipc/msg.c::expunge_all and ipc/sem.c::wake_up_sem_queue_prepare. Fix\nthose in the same way."}], "metrics": [{"cvssV3_1": {"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"}, "scenarios": [{"lang": "en", "value": "AV:L - The bug is triggered through local IPC syscalls (mq_timedsend/mq_timedreceive, msgsnd/msgrcv/msgctl, semop/semctl) and is not reachable by processing remote or adjacent-link network traffic.\nAC:L - The attacker fully controls both sides of the race by running concurrent sender and receiver (or RMID) operations on their own message queue or semaphore set, so success does not depend on an external condition outside their influence.\nPR:L - An unprivileged local user can mq_open/msgget/semget their own objects and exercise send/receive/RMID paths; CAP_SYS_RESOURCE is only needed to exceed resource limits, not to hit the vulnerable code.\nUI:N - The attacker performs the concurrent IPC operations themselves and does not need any separate victim or administrator action.\nS:U - This is a standard in-kernel stack use-after-free within the host OS authority and does not cross a VM, IOMMU, or other security boundary.\nC:H - The dangling stack pointer is reloaded into wake_q_add_safe as a task_struct *, and this stack UAF can be leveraged via stack reuse/heap primitives for arbitrary kernel memory disclosure under UAF scoring guidance.\nI:H - wake_q_add_safe/__wake_q_add perform cmpxchg and list writes through the attacker-influenced task pointer and may put_task_struct/wake_up_process on a bogus object, yielding write and control-flow hijack primitives.\nA:H - The issue was observed to crash in wake_q_add_safe with a bogus task_struct pointer, so kernel oops/panic availability impact is High even without a full exploit."}]}], "affected": [{"product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["ipc/mqueue.c", "ipc/msg.c", "ipc/sem.c"], "versions": [{"version": "c5b2cbdbdac563f46ecd5e187253ab1abbd6fc04", "lessThan": "4528c0c323085e645b8765913b4a7fd42cf49b65", "status": "affected", "versionType": "git"}, {"version": "c5b2cbdbdac563f46ecd5e187253ab1abbd6fc04", "lessThan": "807fa14536b26803b858da878b643be72952a097", "status": "affected", "versionType": "git"}, {"version": "c5b2cbdbdac563f46ecd5e187253ab1abbd6fc04", "lessThan": "a11ddb37bf367e6b5239b95ca759e5389bb46048", "status": "affected", "versionType": "git"}]}, {"product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["ipc/mqueue.c", "ipc/msg.c", "ipc/sem.c"], "versions": [{"version": "5.6", "status": "affected"}, {"version": "0", "lessThan": "5.6", "status": "unaffected", "versionType": "semver"}, {"version": "5.10.40", "lessThanOrEqual": "5.10.*", "status": "unaffected", "versionType": "semver"}, {"version": "5.12.7", "lessThanOrEqual": "5.12.*", "status": "unaffected", "versionType": "semver"}, {"version": "5.13", "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": "5.6", "versionEndExcluding": "5.10.40"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.6", "versionEndExcluding": "5.12.7"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.6", "versionEndExcluding": "5.13"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/4528c0c323085e645b8765913b4a7fd42cf49b65"}, {"url": "https://git.kernel.org/stable/c/807fa14536b26803b858da878b643be72952a097"}, {"url": "https://git.kernel.org/stable/c/a11ddb37bf367e6b5239b95ca759e5389bb46048"}], "title": "ipc/mqueue, msg, sem: avoid relying on a stack reference past its expiry", "x_generator": {"engine": "bippy-1.2.0"}}, "adp": [{"metrics": [{"other": {"type": "ssvc", "content": {"timestamp": "2024-06-21T16:15:09.996738Z", "id": "CVE-2021-47069", "options": [{"Exploitation": "none"}, {"Automatable": "no"}, {"Technical Impact": "partial"}], "role": "CISA Coordinator", "version": "2.0.3"}}}], "title": "CISA ADP Vulnrichment", "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2024-06-21T16:15:20.262Z"}}, {"providerMetadata": {"orgId": "af854a3a-2127-422b-91ae-364da2661108", "shortName": "CVE", "dateUpdated": "2024-08-04T05:24:39.653Z"}, "title": "CVE Program Container", "references": [{"url": "https://git.kernel.org/stable/c/4528c0c323085e645b8765913b4a7fd42cf49b65", "tags": ["x_transferred"]}, {"url": "https://git.kernel.org/stable/c/807fa14536b26803b858da878b643be72952a097", "tags": ["x_transferred"]}, {"url": "https://git.kernel.org/stable/c/a11ddb37bf367e6b5239b95ca759e5389bb46048", "tags": ["x_transferred"]}]}]}}

{"dataType": "CVE_RECORD", "containers": {"adp": [{"title": "CVE Program Container", "references": [{"url": "https://git.kernel.org/stable/c/4528c0c323085e645b8765913b4a7fd42cf49b65", "tags": ["x_transferred"]}, {"url": "https://git.kernel.org/stable/c/807fa14536b26803b858da878b643be72952a097", "tags": ["x_transferred"]}, {"url": "https://git.kernel.org/stable/c/a11ddb37bf367e6b5239b95ca759e5389bb46048", "tags": ["x_transferred"]}], "providerMetadata": {"orgId": "af854a3a-2127-422b-91ae-364da2661108", "shortName": "CVE", "dateUpdated": "2024-08-04T05:24:39.653Z"}}, {"title": "CISA ADP Vulnrichment", "metrics": [{"other": {"type": "ssvc", "content": {"id": "CVE-2021-47069", "role": "CISA Coordinator", "options": [{"Exploitation": "none"}, {"Automatable": "no"}, {"Technical Impact": "partial"}], "version": "2.0.3", "timestamp": "2024-06-21T16:15:09.996738Z"}}}], "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2024-06-21T16:15:15.682Z"}}], "cna": {"title": "ipc/mqueue, msg, sem: avoid relying on a stack reference past its expiry", "metrics": [{"cvssV3_1": {"version": "3.1", "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"}, "scenarios": [{"lang": "en", "value": "AV:L - The bug is triggered through local IPC syscalls (mq_timedsend/mq_timedreceive, msgsnd/msgrcv/msgctl, semop/semctl) and is not reachable by processing remote or adjacent-link network traffic.\nAC:L - The attacker fully controls both sides of the race by running concurrent sender and receiver (or RMID) operations on their own message queue or semaphore set, so success does not depend on an external condition outside their influence.\nPR:L - An unprivileged local user can mq_open/msgget/semget their own objects and exercise send/receive/RMID paths; CAP_SYS_RESOURCE is only needed to exceed resource limits, not to hit the vulnerable code.\nUI:N - The attacker performs the concurrent IPC operations themselves and does not need any separate victim or administrator action.\nS:U - This is a standard in-kernel stack use-after-free within the host OS authority and does not cross a VM, IOMMU, or other security boundary.\nC:H - The dangling stack pointer is reloaded into wake_q_add_safe as a task_struct *, and this stack UAF can be leveraged via stack reuse/heap primitives for arbitrary kernel memory disclosure under UAF scoring guidance.\nI:H - wake_q_add_safe/__wake_q_add perform cmpxchg and list writes through the attacker-influenced task pointer and may put_task_struct/wake_up_process on a bogus object, yielding write and control-flow hijack primitives.\nA:H - The issue was observed to crash in wake_q_add_safe with a bogus task_struct pointer, so kernel oops/panic availability impact is High even without a full exploit."}]}], "affected": [{"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "product": "Linux", "versions": [{"status": "affected", "version": "c5b2cbdbdac563f46ecd5e187253ab1abbd6fc04", "lessThan": "4528c0c323085e645b8765913b4a7fd42cf49b65", "versionType": "git"}, {"status": "affected", "version": "c5b2cbdbdac563f46ecd5e187253ab1abbd6fc04", "lessThan": "807fa14536b26803b858da878b643be72952a097", "versionType": "git"}, {"status": "affected", "version": "c5b2cbdbdac563f46ecd5e187253ab1abbd6fc04", "lessThan": "a11ddb37bf367e6b5239b95ca759e5389bb46048", "versionType": "git"}], "programFiles": ["ipc/mqueue.c", "ipc/msg.c", "ipc/sem.c"], "defaultStatus": "unaffected"}, {"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "product": "Linux", "versions": [{"status": "affected", "version": "5.6"}, {"status": "unaffected", "version": "0", "lessThan": "5.6", "versionType": "semver"}, {"status": "unaffected", "version": "5.10.40", "versionType": "semver", "lessThanOrEqual": "5.10.*"}, {"status": "unaffected", "version": "5.12.7", "versionType": "semver", "lessThanOrEqual": "5.12.*"}, {"status": "unaffected", "version": "5.13", "versionType": "original_commit_for_fix", "lessThanOrEqual": "*"}], "programFiles": ["ipc/mqueue.c", "ipc/msg.c", "ipc/sem.c"], "defaultStatus": "affected"}], "references": [{"url": "https://git.kernel.org/stable/c/4528c0c323085e645b8765913b4a7fd42cf49b65"}, {"url": "https://git.kernel.org/stable/c/807fa14536b26803b858da878b643be72952a097"}, {"url": "https://git.kernel.org/stable/c/a11ddb37bf367e6b5239b95ca759e5389bb46048"}], "x_generator": {"engine": "bippy-1.2.0"}, "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nipc/mqueue, msg, sem: avoid relying on a stack reference past its expiry\n\ndo_mq_timedreceive calls wq_sleep with a stack local address. The\nsender (do_mq_timedsend) uses this address to later call pipelined_send.\n\nThis leads to a very hard to trigger race where a do_mq_timedreceive\ncall might return and leave do_mq_timedsend to rely on an invalid\naddress, causing the following crash:\n\n RIP: 0010:wake_q_add_safe+0x13/0x60\n Call Trace:\n __x64_sys_mq_timedsend+0x2a9/0x490\n do_syscall_64+0x80/0x680\n entry_SYSCALL_64_after_hwframe+0x44/0xa9\n RIP: 0033:0x7f5928e40343\n\nThe race occurs as:\n\n1. do_mq_timedreceive calls wq_sleep with the address of `struct\n ext_wait_queue` on function stack (aliased as `ewq_addr` here) - it\n holds a valid `struct ext_wait_queue *` as long as the stack has not\n been overwritten.\n\n2. `ewq_addr` gets added to info->e_wait_q[RECV].list in wq_add, and\n do_mq_timedsend receives it via wq_get_first_waiter(info, RECV) to call\n __pipelined_op.\n\n3. Sender calls __pipelined_op::smp_store_release(&this->state,\n STATE_READY). Here is where the race window begins. (`this` is\n `ewq_addr`.)\n\n4. If the receiver wakes up now in do_mq_timedreceive::wq_sleep, it\n will see `state == STATE_READY` and break.\n\n5. do_mq_timedreceive returns, and `ewq_addr` is no longer guaranteed\n to be a `struct ext_wait_queue *` since it was on do_mq_timedreceive's\n stack. (Although the address may not get overwritten until another\n function happens to touch it, which means it can persist around for an\n indefinite time.)\n\n6. do_mq_timedsend::__pipelined_op() still believes `ewq_addr` is a\n `struct ext_wait_queue *`, and uses it to find a task_struct to pass to\n the wake_q_add_safe call. In the lucky case where nothing has\n overwritten `ewq_addr` yet, `ewq_addr->task` is the right task_struct.\n In the unlucky case, __pipelined_op::wake_q_add_safe gets handed a\n bogus address as the receiver's task_struct causing the crash.\n\ndo_mq_timedsend::__pipelined_op() should not dereference `this` after\nsetting STATE_READY, as the receiver counterpart is now free to return.\nChange __pipelined_op to call wake_q_add_safe on the receiver's\ntask_struct returned by get_task_struct, instead of dereferencing `this`\nwhich sits on the receiver's stack.\n\nAs Manfred pointed out, the race potentially also exists in\nipc/msg.c::expunge_all and ipc/sem.c::wake_up_sem_queue_prepare. Fix\nthose in the same way."}], "cpeApplicability": [{"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "versionEndExcluding": "5.10.40", "versionStartIncluding": "5.6"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "versionEndExcluding": "5.12.7", "versionStartIncluding": "5.6"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "versionEndExcluding": "5.13", "versionStartIncluding": "5.6"}], "operator": "OR"}]}], "providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T08:45:50.647Z"}}}, "cveMetadata": {"cveId": "CVE-2021-47069", "state": "PUBLISHED", "dateUpdated": "2026-08-05T08:45:50.647Z", "dateReserved": "2024-02-29T22:33:44.296Z", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "datePublished": "2024-03-01T21:15:08.598Z", "assignerShortName": "Linux"}, "dataVersion": "5.2"}

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The\nsender (do_mq_timedsend) uses this address to later call pipelined_send.\n\nThis leads to a very hard to trigger race where a do_mq_timedreceive\ncall might return and leave do_mq_timedsend to rely on an invalid\naddress, causing the following crash:\n\n RIP: 0010:wake_q_add_safe+0x13/0x60\n Call Trace:\n __x64_sys_mq_timedsend+0x2a9/0x490\n do_syscall_64+0x80/0x680\n entry_SYSCALL_64_after_hwframe+0x44/0xa9\n RIP: 0033:0x7f5928e40343\n\nThe race occurs as:\n\n1. do_mq_timedreceive calls wq_sleep with the address of `struct\n ext_wait_queue` on function stack (aliased as `ewq_addr` here) - it\n holds a valid `struct ext_wait_queue *` as long as the stack has not\n been overwritten.\n\n2. `ewq_addr` gets added to info->e_wait_q[RECV].list in wq_add, and\n do_mq_timedsend receives it via wq_get_first_waiter(info, RECV) to call\n __pipelined_op.\n\n3. Sender calls __pipelined_op::smp_store_release(&this->state,\n STATE_READY). Here is where the race window begins. (`this` is\n `ewq_addr`.)\n\n4. If the receiver wakes up now in do_mq_timedreceive::wq_sleep, it\n will see `state == STATE_READY` and break.\n\n5. do_mq_timedreceive returns, and `ewq_addr` is no longer guaranteed\n to be a `struct ext_wait_queue *` since it was on do_mq_timedreceive's\n stack. (Although the address may not get overwritten until another\n function happens to touch it, which means it can persist around for an\n indefinite time.)\n\n6. do_mq_timedsend::__pipelined_op() still believes `ewq_addr` is a\n `struct ext_wait_queue *`, and uses it to find a task_struct to pass to\n the wake_q_add_safe call. In the lucky case where nothing has\n overwritten `ewq_addr` yet, `ewq_addr->task` is the right task_struct.\n In the unlucky case, __pipelined_op::wake_q_add_safe gets handed a\n bogus address as the receiver's task_struct causing the crash.\n\ndo_mq_timedsend::__pipelined_op() should not dereference `this` after\nsetting STATE_READY, as the receiver counterpart is now free to return.\nChange __pipelined_op to call wake_q_add_safe on the receiver's\ntask_struct returned by get_task_struct, instead of dereferencing `this`\nwhich sits on the receiver's stack.\n\nAs Manfred pointed out, the race potentially also exists in\nipc/msg.c::expunge_all and ipc/sem.c::wake_up_sem_queue_prepare. Fix\nthose in the same way."}, {"lang": "es", "value": "En el kernel de Linux, se resolvi\u00f3 la siguiente vulnerabilidad: ipc/mqueue, msg, sem: evite confiar en una referencia de pila despu\u00e9s de su vencimiento do_mq_timedreceive llama a wq_sleep con una direcci\u00f3n local de pila. El remitente (do_mq_timedsend) usa esta direcci\u00f3n para luego llamar a pipelined_send. Esto conduce a una ejecuci\u00f3n muy dif\u00edcil de desencadenar en la que una llamada do_mq_timedreceive puede regresar y dejar que do_mq_timedsend dependa de una direcci\u00f3n no v\u00e1lida, lo que provoca el siguiente bloqueo: RIP: 0010:wake_q_add_safe+0x13/0x60 Seguimiento de llamadas: __x64_sys_mq_timedsend+0x2a9/0x490 do_syscall_64+0x80 /0x680 Entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x7f5928e40343 La ejecuci\u00f3n ocurre como: 1. do_mq_timedreceive llama a wq_sleep con la direcci\u00f3n de `struct ext_wait_queue` en la pila de funciones (alias `ewq_addr` aqu\u00ed): contiene una `struct ext_wait_queue * v\u00e1lida ` siempre y cuando la pila no haya sido sobrescrita. 2. `ewq_addr` se agrega a info->e_wait_q[RECV].list en wq_add, y do_mq_timedsend lo recibe a trav\u00e9s de wq_get_first_waiter(info, RECV) para llamar a __pipelined_op. 3. El remitente llama a __pipelined_op::smp_store_release(&this->state, STATE_READY). Aqu\u00ed es donde comienza la ventana de ejecuci\u00f3n. (`esto` es `ewq_addr`.) 4. Si el receptor se activa ahora en do_mq_timedreceive::wq_sleep, ver\u00e1 `state == STATE_READY` y se interrumpir\u00e1. 5. do_mq_timedreceive regresa y ya no se garantiza que `ewq_addr` sea una `struct ext_wait_queue *` ya que estaba en la pila de do_mq_timedreceive. (Aunque es posible que la direcci\u00f3n no se sobrescriba hasta que otra funci\u00f3n la toque, lo que significa que puede persistir por un tiempo indefinido). 6. do_mq_timedsend::__pipelined_op() todav\u00eda cree que `ewq_addr` es una `struct ext_wait_queue *`, y lo usa para encontrar una task_struct para pasar a la llamada wake_q_add_safe. En el afortunado caso de que nada haya sobrescrito `ewq_addr` todav\u00eda, `ewq_addr->task` es la estructura de tarea correcta. En el desafortunado caso, __pipelined_op::wake_q_add_safe recibe una direcci\u00f3n falsa como la task_struct del receptor que causa el bloqueo. do_mq_timedsend::__pipelined_op() no debe eliminar la referencia a \"esto\" despu\u00e9s de configurar STATE_READY, ya que la contraparte del receptor ahora puede regresar. Cambie __pipelined_op para llamar a wake_q_add_safe en el task_struct del receptor devuelto por get_task_struct, en lugar de desreferenciar \"this\" que se encuentra en la pila del receptor. Como se\u00f1al\u00f3 Manfred, la ejecuci\u00f3n tambi\u00e9n existe potencialmente en ipc/msg.c::expunge_all e ipc/sem.c::wake_up_sem_queue_prepare. Arr\u00e9glelos de la misma manera."}], "id": "CVE-2021-47069", "lastModified": "2026-08-04T10:16:44.070", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "LOW", "attackVector": "LOCAL", "availabilityImpact": "HIGH", "baseScore": 7.8, "baseSeverity": "HIGH", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "privilegesRequired": "LOW", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H", "version": "3.1"}, "exploitabilityScore": 1.8, "impactScore": 5.9, "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "type": "Secondary"}, {"cvssData": {"attackComplexity": "HIGH", "attackVector": "LOCAL", "availabilityImpact": "HIGH", "baseScore": 7.0, "baseSeverity": "HIGH", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "privilegesRequired": "LOW", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H", "version": "3.1"}, "exploitabilityScore": 1.0, "impactScore": 5.9, "source": "nvd@nist.gov", "type": "Primary"}], "ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2021-47069", "options": [{"exploitation": "none"}, {"automatable": "no"}, {"technicalImpact": "partial"}], "role": "CISA Coordinator", "timestamp": "2024-06-21T16:15:09.996738Z", "version": "2.0.3"}}]}, "published": "2024-03-01T22:15:46.857", "references": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/4528c0c323085e645b8765913b4a7fd42cf49b65"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/807fa14536b26803b858da878b643be72952a097"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/a11ddb37bf367e6b5239b95ca759e5389bb46048"}, {"source": "af854a3a-2127-422b-91ae-364da2661108", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/4528c0c323085e645b8765913b4a7fd42cf49b65"}, {"source": "af854a3a-2127-422b-91ae-364da2661108", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/807fa14536b26803b858da878b643be72952a097"}, {"source": "af854a3a-2127-422b-91ae-364da2661108", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/a11ddb37bf367e6b5239b95ca759e5389bb46048"}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "vulnStatus": "Modified", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-672"}], "source": "nvd@nist.gov", "type": "Primary"}]}

{"affected_release": [{"advisory": "RHSA-2024:4352", "cpe": "cpe:/a:redhat:enterprise_linux:8::nfv", "package": "kernel-rt-0:4.18.0-553.8.1.rt7.349.el8_10", "product_name": "Red Hat Enterprise Linux 8", "release_date": "2024-07-08T00:00:00Z"}, {"advisory": "RHSA-2024:4211", "cpe": "cpe:/o:redhat:enterprise_linux:8", "package": "kernel-0:4.18.0-553.8.1.el8_10", "product_name": "Red Hat Enterprise Linux 8", "release_date": "2024-07-02T00:00:00Z"}, {"advisory": "RHSA-2024:5692", "cpe": "cpe:/o:redhat:rhel_aus:8.6", "package": "kernel-0:4.18.0-372.119.1.el8_6", "product_name": "Red Hat Enterprise Linux 8.6 Advanced Mission Critical Update Support", "release_date": "2024-08-21T00:00:00Z"}, {"advisory": "RHSA-2024:5692", "cpe": "cpe:/o:redhat:rhel_tus:8.6", "package": "kernel-0:4.18.0-372.119.1.el8_6", "product_name": "Red Hat Enterprise Linux 8.6 Telecommunications Update Service", "release_date": "2024-08-21T00:00:00Z"}, {"advisory": "RHSA-2024:5692", "cpe": "cpe:/o:redhat:rhel_e4s:8.6", "package": "kernel-0:4.18.0-372.119.1.el8_6", "product_name": "Red Hat Enterprise Linux 8.6 Update Services for SAP Solutions", "release_date": "2024-08-21T00:00:00Z"}, {"advisory": "RHSA-2024:6206", "cpe": "cpe:/o:redhat:rhel_eus:8.8", "package": "kernel-0:4.18.0-477.70.1.el8_8", "product_name": "Red Hat Enterprise Linux 8.8 Extended Update Support", "release_date": "2024-09-03T00:00:00Z"}], "bugzilla": {"description": "kernel: ipc/mqueue, msg, sem: avoid relying on a stack reference past its expiry", "id": "2267513", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2267513"}, "csaw": false, "cvss3": {"cvss3_base_score": "5.8", "cvss3_scoring_vector": "CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:L/I:L/A:H", "status": "verified"}, "cwe": "CWE-362", "details": ["In the Linux kernel, the following vulnerability has been resolved:\nipc/mqueue, msg, sem: avoid relying on a stack reference past its expiry\ndo_mq_timedreceive calls wq_sleep with a stack local address. The\nsender (do_mq_timedsend) uses this address to later call pipelined_send.\nThis leads to a very hard to trigger race where a do_mq_timedreceive\ncall might return and leave do_mq_timedsend to rely on an invalid\naddress, causing the following crash:\nRIP: 0010:wake_q_add_safe+0x13/0x60\nCall Trace:\n__x64_sys_mq_timedsend+0x2a9/0x490\ndo_syscall_64+0x80/0x680\nentry_SYSCALL_64_after_hwframe+0x44/0xa9\nRIP: 0033:0x7f5928e40343\nThe race occurs as:\n1. do_mq_timedreceive calls wq_sleep with the address of `struct\next_wait_queue` on function stack (aliased as `ewq_addr` here) - it\nholds a valid `struct ext_wait_queue *` as long as the stack has not\nbeen overwritten.\n2. `ewq_addr` gets added to info->e_wait_q[RECV].list in wq_add, and\ndo_mq_timedsend receives it via wq_get_first_waiter(info, RECV) to call\n__pipelined_op.\n3. Sender calls __pipelined_op::smp_store_release(&this->state,\nSTATE_READY). Here is where the race window begins. (`this` is\n`ewq_addr`.)\n4. If the receiver wakes up now in do_mq_timedreceive::wq_sleep, it\nwill see `state == STATE_READY` and break.\n5. do_mq_timedreceive returns, and `ewq_addr` is no longer guaranteed\nto be a `struct ext_wait_queue *` since it was on do_mq_timedreceive's\nstack. (Although the address may not get overwritten until another\nfunction happens to touch it, which means it can persist around for an\nindefinite time.)\n6. do_mq_timedsend::__pipelined_op() still believes `ewq_addr` is a\n`struct ext_wait_queue *`, and uses it to find a task_struct to pass to\nthe wake_q_add_safe call. In the lucky case where nothing has\noverwritten `ewq_addr` yet, `ewq_addr->task` is the right task_struct.\nIn the unlucky case, __pipelined_op::wake_q_add_safe gets handed a\nbogus address as the receiver's task_struct causing the crash.\ndo_mq_timedsend::__pipelined_op() should not dereference `this` after\nsetting STATE_READY, as the receiver counterpart is now free to return.\nChange __pipelined_op to call wake_q_add_safe on the receiver's\ntask_struct returned by get_task_struct, instead of dereferencing `this`\nwhich sits on the receiver's stack.\nAs Manfred pointed out, the race potentially also exists in\nipc/msg.c::expunge_all and ipc/sem.c::wake_up_sem_queue_prepare. Fix\nthose in the same way.", "A flaw was found in the Linux kernel\u2019s IPC system. This flaw allows an attacker to use a specially crafted program to cause a rare race condition, leading to a denial of service."], "mitigation": {"lang": "en:us", "value": "Red Hat has investigated whether a possible mitigation exists for this issue, and has not been able to identify a practical example. Please update the affected package as soon as possible."}, "name": "CVE-2021-47069", "package_state": [{"cpe": "cpe:/o:redhat:enterprise_linux:6", "fix_state": "Out of support scope", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 6"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Out of support scope", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Out of support scope", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 9"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Not affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 9"}], "public_date": "2024-03-01T00:00:00Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2021-47069\nhttps://nvd.nist.gov/vuln/detail/CVE-2021-47069\nhttps://lore.kernel.org/linux-cve-announce/2024030141-CVE-2021-47069-5797@gregkh/T/#u"], "statement": "Red Hat Enterprise Linux 9 is not affected by this vulnerability.", "threat_severity": "Moderate"}

{}