{"resultsPerPage":1,"startIndex":0,"totalResults":1,"format":"NVD_CVE","version":"2.0","timestamp":"2026-05-01T22:16:42.244","vulnerabilities":[{"cve":{"id":"CVE-2021-47069","sourceIdentifier":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","published":"2024-03-01T22:15:46.857","lastModified":"2025-01-09T18:21:01.560","vulnStatus":"Analyzed","cveTags":[],"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."},{"lang":"es","value":"En el kernel de Linux, se resolvió la siguiente vulnerabilidad: ipc/mqueue, msg, sem: evite confiar en una referencia de pila después de su vencimiento do_mq_timedreceive llama a wq_sleep con una dirección local de pila. El remitente (do_mq_timedsend) usa esta dirección para luego llamar a pipelined_send. Esto conduce a una ejecución muy difícil de desencadenar en la que una llamada do_mq_timedreceive puede regresar y dejar que do_mq_timedsend dependa de una dirección no válida, 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 ejecución ocurre como: 1. do_mq_timedreceive llama a wq_sleep con la dirección de `struct ext_wait_queue` en la pila de funciones (alias `ewq_addr` aquí): contiene una `struct ext_wait_queue * válida ` 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 través 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). Aquí es donde comienza la ventana de ejecución. (`esto` es `ewq_addr`.) 4. Si el receptor se activa ahora en do_mq_timedreceive::wq_sleep, verá `state == STATE_READY` y se interrumpirá. 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 dirección no se sobrescriba hasta que otra función la toque, lo que significa que puede persistir por un tiempo indefinido). 6. do_mq_timedsend::__pipelined_op() todavía 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` todavía, `ewq_addr->task` es la estructura de tarea correcta. En el desafortunado caso, __pipelined_op::wake_q_add_safe recibe una dirección falsa como la task_struct del receptor que causa el bloqueo. do_mq_timedsend::__pipelined_op() no debe eliminar la referencia a \"esto\" después 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 señaló Manfred, la ejecución también existe potencialmente en ipc/msg.c::expunge_all e ipc/sem.c::wake_up_sem_queue_prepare. Arréglelos de la misma manera."}],"metrics":{"cvssMetricV31":[{"source":"nvd@nist.gov","type":"Primary","cvssData":{"version":"3.1","vectorString":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H","baseScore":7.0,"baseSeverity":"HIGH","attackVector":"LOCAL","attackComplexity":"HIGH","privilegesRequired":"LOW","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"HIGH","integrityImpact":"HIGH","availabilityImpact":"HIGH"},"exploitabilityScore":1.0,"impactScore":5.9}]},"weaknesses":[{"source":"nvd@nist.gov","type":"Primary","description":[{"lang":"en","value":"CWE-672"}]}],"configurations":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.6","versionEndExcluding":"5.10.40","matchCriteriaId":"CC04C860-B3F3-4630-B20D-99BEA8F2A42A"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.11","versionEndExcluding":"5.12.7","matchCriteriaId":"E8F2CE30-38B0-4716-B12B-A139B0F9C5C9"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:5.13:rc1:*:*:*:*:*:*","matchCriteriaId":"0CBAD0FC-C281-4666-AB2F-F8E6E1165DF7"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:5.13:rc2:*:*:*:*:*:*","matchCriteriaId":"96AC23B2-D46A-49D9-8203-8E1BEDCA8532"}]}]}],"references":[{"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":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","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","source":"af854a3a-2127-422b-91ae-364da2661108","tags":["Patch"]}]}}]}