{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2024-50154","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","state":"PUBLISHED","assignerShortName":"Linux","dateReserved":"2024-10-21T19:36:19.960Z","datePublished":"2024-11-07T09:31:30.855Z","dateUpdated":"2025-11-03T22:26:13.271Z"},"containers":{"cna":{"providerMetadata":{"orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux","dateUpdated":"2025-05-04T12:59:37.593Z"},"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"}],"affected":[{"product":"Linux","vendor":"Linux","defaultStatus":"unaffected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/ipv4/inet_connection_sock.c"],"versions":[{"version":"83fccfc3940c4a2db90fd7e7079f5b465cd8c6af","lessThan":"106e457953315e476b3642ef24be25ed862aaba3","status":"affected","versionType":"git"},{"version":"83fccfc3940c4a2db90fd7e7079f5b465cd8c6af","lessThan":"c964bf65f80a14288d767023a1b300b30f5b9cd0","status":"affected","versionType":"git"},{"version":"83fccfc3940c4a2db90fd7e7079f5b465cd8c6af","lessThan":"8459d61fbf24967839a70235165673148c7c7f17","status":"affected","versionType":"git"},{"version":"83fccfc3940c4a2db90fd7e7079f5b465cd8c6af","lessThan":"5071beb59ee416e8ab456ac8647a4dabcda823b1","status":"affected","versionType":"git"},{"version":"83fccfc3940c4a2db90fd7e7079f5b465cd8c6af","lessThan":"997ae8da14f1639ce6fb66a063dab54031cd61b3","status":"affected","versionType":"git"},{"version":"83fccfc3940c4a2db90fd7e7079f5b465cd8c6af","lessThan":"51e34db64f4e43c7b055ccf881b7f3e0c31bb26d","status":"affected","versionType":"git"},{"version":"83fccfc3940c4a2db90fd7e7079f5b465cd8c6af","lessThan":"e8c526f2bdf1845bedaf6a478816a3d06fa78b8f","status":"affected","versionType":"git"},{"version":"d3a1196bfc462943694623412d8e03aaf172bdc1","status":"affected","versionType":"git"}]},{"product":"Linux","vendor":"Linux","defaultStatus":"affected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/ipv4/inet_connection_sock.c"],"versions":[{"version":"4.2","status":"affected"},{"version":"0","lessThan":"4.2","status":"unaffected","versionType":"semver"},{"version":"5.4.293","lessThanOrEqual":"5.4.*","status":"unaffected","versionType":"semver"},{"version":"5.10.237","lessThanOrEqual":"5.10.*","status":"unaffected","versionType":"semver"},{"version":"5.15.170","lessThanOrEqual":"5.15.*","status":"unaffected","versionType":"semver"},{"version":"6.1.115","lessThanOrEqual":"6.1.*","status":"unaffected","versionType":"semver"},{"version":"6.6.59","lessThanOrEqual":"6.6.*","status":"unaffected","versionType":"semver"},{"version":"6.11.6","lessThanOrEqual":"6.11.*","status":"unaffected","versionType":"semver"},{"version":"6.12","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":"4.2","versionEndExcluding":"5.4.293"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.2","versionEndExcluding":"5.10.237"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.2","versionEndExcluding":"5.15.170"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.2","versionEndExcluding":"6.1.115"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.2","versionEndExcluding":"6.6.59"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.2","versionEndExcluding":"6.11.6"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.2","versionEndExcluding":"6.12"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.1.11"}]}]}],"references":[{"url":"https://git.kernel.org/stable/c/106e457953315e476b3642ef24be25ed862aaba3"},{"url":"https://git.kernel.org/stable/c/c964bf65f80a14288d767023a1b300b30f5b9cd0"},{"url":"https://git.kernel.org/stable/c/8459d61fbf24967839a70235165673148c7c7f17"},{"url":"https://git.kernel.org/stable/c/5071beb59ee416e8ab456ac8647a4dabcda823b1"},{"url":"https://git.kernel.org/stable/c/997ae8da14f1639ce6fb66a063dab54031cd61b3"},{"url":"https://git.kernel.org/stable/c/51e34db64f4e43c7b055ccf881b7f3e0c31bb26d"},{"url":"https://git.kernel.org/stable/c/e8c526f2bdf1845bedaf6a478816a3d06fa78b8f"}],"title":"tcp/dccp: Don't use timer_pending() in reqsk_queue_unlink().","x_generator":{"engine":"bippy-1.2.0"}},"adp":[{"metrics":[{"cvssV3_1":{"scope":"UNCHANGED","version":"3.1","baseScore":7.8,"attackVector":"LOCAL","baseSeverity":"HIGH","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","integrityImpact":"HIGH","userInteraction":"NONE","attackComplexity":"LOW","availabilityImpact":"HIGH","privilegesRequired":"LOW","confidentialityImpact":"HIGH"}},{"other":{"type":"ssvc","content":{"id":"CVE-2024-50154","role":"CISA Coordinator","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"total"}],"version":"2.0.3","timestamp":"2024-12-11T14:25:48.087506Z"}}}],"problemTypes":[{"descriptions":[{"lang":"en","type":"CWE","cweId":"CWE-416","description":"CWE-416 Use After Free"}]}],"title":"CISA ADP Vulnrichment","providerMetadata":{"orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","shortName":"CISA-ADP","dateUpdated":"2024-12-11T14:58:32.999Z"}},{"title":"CVE Program Container","references":[{"url":"https://lists.debian.org/debian-lts-announce/2025/05/msg00030.html"},{"url":"https://lists.debian.org/debian-lts-announce/2025/01/msg00001.html"}],"providerMetadata":{"orgId":"af854a3a-2127-422b-91ae-364da2661108","shortName":"CVE","dateUpdated":"2025-11-03T22:26:13.271Z"}}]}}