{"resultsPerPage":1,"startIndex":0,"totalResults":1,"format":"NVD_CVE","version":"2.0","timestamp":"2026-04-21T19:48:52.818","vulnerabilities":[{"cve":{"id":"CVE-2024-50154","sourceIdentifier":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","published":"2024-11-07T10:15:06.987","lastModified":"2025-11-03T23:16:56.237","vulnStatus":"Modified","cveTags":[],"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\ntcp/dccp: Don't use timer_pending() in reqsk_queue_unlink().\n\nMartin KaFai Lau reported use-after-free [0] in reqsk_timer_handler().\n\n  \"\"\"\n  We are seeing a use-after-free from a bpf prog attached to\n  trace_tcp_retransmit_synack. The program passes the req->sk to the\n  bpf_sk_storage_get_tracing kernel helper which does check for null\n  before using it.\n  \"\"\"\n\nThe commit 83fccfc3940c (\"inet: fix potential deadlock in\nreqsk_queue_unlink()\") added timer_pending() in reqsk_queue_unlink() not\nto call del_timer_sync() from reqsk_timer_handler(), but it introduced a\nsmall race window.\n\nBefore the timer is called, expire_timers() calls detach_timer(timer, true)\nto clear timer->entry.pprev and marks it as not pending.\n\nIf reqsk_queue_unlink() checks timer_pending() just after expire_timers()\ncalls detach_timer(), TCP will miss del_timer_sync(); the reqsk timer will\ncontinue running and send multiple SYN+ACKs until it expires.\n\nThe reported UAF could happen if req->sk is close()d earlier than the timer\nexpiration, which is 63s by default.\n\nThe scenario would be\n\n  1. inet_csk_complete_hashdance() calls inet_csk_reqsk_queue_drop(),\n     but del_timer_sync() is missed\n\n  2. reqsk timer is executed and scheduled again\n\n  3. req->sk is accept()ed and reqsk_put() decrements rsk_refcnt, but\n     reqsk timer still has another one, and inet_csk_accept() does not\n     clear req->sk for non-TFO sockets\n\n  4. sk is close()d\n\n  5. reqsk timer is executed again, and BPF touches req->sk\n\nLet's not use timer_pending() by passing the caller context to\n__inet_csk_reqsk_queue_drop().\n\nNote that reqsk timer is pinned, so the issue does not happen in most\nuse cases. [1]\n\n[0]\nBUG: KFENCE: use-after-free read in bpf_sk_storage_get_tracing+0x2e/0x1b0\n\nUse-after-free read at 0x00000000a891fb3a (in kfence-#1):\nbpf_sk_storage_get_tracing+0x2e/0x1b0\nbpf_prog_5ea3e95db6da0438_tcp_retransmit_synack+0x1d20/0x1dda\nbpf_trace_run2+0x4c/0xc0\ntcp_rtx_synack+0xf9/0x100\nreqsk_timer_handler+0xda/0x3d0\nrun_timer_softirq+0x292/0x8a0\nirq_exit_rcu+0xf5/0x320\nsysvec_apic_timer_interrupt+0x6d/0x80\nasm_sysvec_apic_timer_interrupt+0x16/0x20\nintel_idle_irq+0x5a/0xa0\ncpuidle_enter_state+0x94/0x273\ncpu_startup_entry+0x15e/0x260\nstart_secondary+0x8a/0x90\nsecondary_startup_64_no_verify+0xfa/0xfb\n\nkfence-#1: 0x00000000a72cc7b6-0x00000000d97616d9, size=2376, cache=TCPv6\n\nallocated by task 0 on cpu 9 at 260507.901592s:\nsk_prot_alloc+0x35/0x140\nsk_clone_lock+0x1f/0x3f0\ninet_csk_clone_lock+0x15/0x160\ntcp_create_openreq_child+0x1f/0x410\ntcp_v6_syn_recv_sock+0x1da/0x700\ntcp_check_req+0x1fb/0x510\ntcp_v6_rcv+0x98b/0x1420\nipv6_list_rcv+0x2258/0x26e0\nnapi_complete_done+0x5b1/0x2990\nmlx5e_napi_poll+0x2ae/0x8d0\nnet_rx_action+0x13e/0x590\nirq_exit_rcu+0xf5/0x320\ncommon_interrupt+0x80/0x90\nasm_common_interrupt+0x22/0x40\ncpuidle_enter_state+0xfb/0x273\ncpu_startup_entry+0x15e/0x260\nstart_secondary+0x8a/0x90\nsecondary_startup_64_no_verify+0xfa/0xfb\n\nfreed by task 0 on cpu 9 at 260507.927527s:\nrcu_core_si+0x4ff/0xf10\nirq_exit_rcu+0xf5/0x320\nsysvec_apic_timer_interrupt+0x6d/0x80\nasm_sysvec_apic_timer_interrupt+0x16/0x20\ncpuidle_enter_state+0xfb/0x273\ncpu_startup_entry+0x15e/0x260\nstart_secondary+0x8a/0x90\nsecondary_startup_64_no_verify+0xfa/0xfb"},{"lang":"es","value":"En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: tcp/dccp: No use timer_pending() en reqsk_queue_unlink(). Martin KaFai Lau informó de un use-after-free [0] en reqsk_timer_handler(). \"\"\" Estamos viendo un use-after-free de un programa bpf adjunto a trace_tcp_retransmit_synack. El programa pasa el req->sk al ayudante del kernel bpf_sk_storage_get_tracing que comprueba si hay valores nulos antes de usarlo. \"\"\" El commit 83fccfc3940c (\"inet: soluciona un posible bloqueo en reqsk_queue_unlink()\") agregó timer_pending() en reqsk_queue_unlink() para no llamar a del_timer_sync() desde reqsk_timer_handler(), pero introdujo una pequeña ventana de ejecución. Antes de que se llame al temporizador, expire_timers() llama a detach_timer(timer, true) para borrar timer->entry.pprev y lo marca como no pendiente. Si reqsk_queue_unlink() comprueba timer_pending() justo después de que expire_timers() llame a detach_timer(), TCP no detectará del_timer_sync(); el temporizador reqsk seguirá funcionando y enviará varios SYN+ACK hasta que expire. El UAF informado podría ocurrir si se cierra req->sk antes de la expiración del temporizador, que es 63 s por defecto. El escenario sería 1. inet_csk_complete_hashdance() llama a inet_csk_reqsk_queue_drop(), pero se omite del_timer_sync() 2. se ejecuta el temporizador reqsk y se programa nuevamente 3. se acepta req->sk y reqsk_put() decrementa rsk_refcnt, pero el temporizador reqsk aún tiene otro, e inet_csk_accept() no borra req->sk para sockets que no sean TFO 4. se cierra sk 5. se ejecuta nuevamente el temporizador reqsk y BPF toca req->sk No usemos timer_pending() pasando el contexto del llamador a __inet_csk_reqsk_queue_drop(). Tenga en cuenta que el temporizador reqsk está fijado, por lo que el problema no ocurre en la mayoría de los casos de uso. [1] [0] ERROR: KFENCE: lectura de use-after-free en bpf_sk_storage_get_tracing+0x2e/0x1b0 Lectura de use-after-free en 0x00000000a891fb3a (en kfence-#1): bpf_sk_storage_get_tracing+0x2e/0x1b0 bpf_prog_5ea3e95db6da0438_tcp_retransmit_synack+0x1d20/0x1dda bpf_trace_run2+0x4c/0xc0 tcp_rtx_synack+0xf9/0x100 reqsk_timer_handler+0xda/0x3d0 run_timer_softirq+0x292/0x8a0 irq_exit_rcu+0xf5/0x320 sysvec_apic_timer_interrupt+0x6d/0x80 asm_sysvec_apic_timer_interrupt+0x16/0x20 intel_idle_irq+0x5a/0xa0 cpuidle_enter_state+0x94/0x273 cpu_startup_entry+0x15e/0x260 start_secondary+0x8a/0x90 secondary_startup_64_no_verify+0xfa/0xfb kfence-#1: 0x00000000a72cc7b6-0x00000000d97616d9, tamaño=2376, caché=TCPv6 asignado por la tarea 0 en la CPU 9 en 260507.901592s: sk_prot_alloc+0x35/0x140 sk_clone_lock+0x1f/0x3f0 inet_csk_clone_lock+0x15/0x160 tcp_create_openreq_child+0x1f/0x410 tcp_v6_syn_recv_sock+0x1da/0x700 tcp_check_req+0x1fb/0x510 tcp_v6_rcv+0x98b/0x1420 ipv6_list_rcv+0x2258/0x26e0 napi_complete_done+0x5b1/0x2990 mlx5e_napi_poll+0x2ae/0x8d0 net_rx_action+0x13e/0x590 irq_exit_rcu+0xf5/0x320 common_interrupt+0x80/0x90 asm_common_interrupt+0x22/0x40 cpuidle_enter_state+0xfb/0x273 cpu_startup_entry+0x15e/0x260 start_secondary+0x8a/0x90 secondary_startup_64_no_verify+0xfa/0xfb liberado por la tarea 0 en la CPU 9 a las 260507.927527 s: rcu_core_si+0x4ff/0xf10 irq_exit_rcu+0xf5/0x320 sysvec_apic_timer_interrupt+0x6d/0x80 asm_sysvec_apic_timer_interrupt+0x16/0x20 cpu_idle_entrada_estado+0xfb/0x273 cpu_inicio_entrada+0x15e/0x260 inicio_secundario+0x8a/0x90 inicio_secundario_64_sin_verificación+0xfa/0xfb"}],"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},{"source":"134c704f-9b21-4f2e-91b3-4a467353bcc0","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}]},"weaknesses":[{"source":"nvd@nist.gov","type":"Primary","description":[{"lang":"en","value":"CWE-416"}]},{"source":"134c704f-9b21-4f2e-91b3-4a467353bcc0","type":"Secondary","description":[{"lang":"en","value":"CWE-416"}]}],"configurations":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.1.11","versionEndExcluding":"4.2","matchCriteriaId":"3CD6E092-00BA-470A-BD6E-9FF38E84DB99"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.2","versionEndExcluding":"5.15.170","matchCriteriaId":"D37DEB92-5329-47EC-94B1-051761C1F534"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.16","versionEndExcluding":"6.1.115","matchCriteriaId":"C08A77A6-E42E-4EFD-B5A1-2BF6CBBB42AE"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.2","versionEndExcluding":"6.6.59","matchCriteriaId":"5D15CA59-D15C-4ACD-8B03-A072DEAD2081"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.7","versionEndExcluding":"6.11.6","matchCriteriaId":"E4486B12-007B-4794-9857-F07145637AA1"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:6.12:rc1:*:*:*:*:*:*","matchCriteriaId":"7F361E1D-580F-4A2D-A509-7615F73167A1"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:6.12:rc2:*:*:*:*:*:*","matchCriteriaId":"925478D0-3E3D-4E6F-ACD5-09F28D5DF82C"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:6.12:rc3:*:*:*:*:*:*","matchCriteriaId":"3C95E234-D335-4B6C-96BF-E2CEBD8654ED"}]}]}],"references":[{"url":"https://git.kernel.org/stable/c/106e457953315e476b3642ef24be25ed862aaba3","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/5071beb59ee416e8ab456ac8647a4dabcda823b1","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":["Patch"]},{"url":"https://git.kernel.org/stable/c/51e34db64f4e43c7b055ccf881b7f3e0c31bb26d","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":["Patch"]},{"url":"https://git.kernel.org/stable/c/8459d61fbf24967839a70235165673148c7c7f17","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":["Patch"]},{"url":"https://git.kernel.org/stable/c/997ae8da14f1639ce6fb66a063dab54031cd61b3","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":["Patch"]},{"url":"https://git.kernel.org/stable/c/c964bf65f80a14288d767023a1b300b30f5b9cd0","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/e8c526f2bdf1845bedaf6a478816a3d06fa78b8f","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":["Patch"]},{"url":"https://lists.debian.org/debian-lts-announce/2025/01/msg00001.html","source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://lists.debian.org/debian-lts-announce/2025/05/msg00030.html","source":"af854a3a-2127-422b-91ae-364da2661108"}]}}]}