{"id":"CVE-2022-50409","title":"net: If sock is dead don't access sock's sk_wq in sk_stream_wait_memory","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet: If sock is dead don't access sock's sk_wq in sk_stream_wait_memory\n\nFixes the below NULL pointer dereference:\n\n  [...]\n  [   14.471200] Call Trace:\n  [   14.471562…","severity":"none","vendor":"Linux","product":"Linux","affected":["Linux >= 604326b41a6fb9b4a78b6179335decee0365cd8c < a76462dbdd8bddcbeec9463bc9e54e509b860762","Linux >= 604326b41a6fb9b4a78b6179335decee0365cd8c < 65029aaedd15d9fe5ea1a899134e236d83f627bb","Linux >= 604326b41a6fb9b4a78b6179335decee0365cd8c < 124b7c773271f06af5a2cea694b283cdb5275cf5","Linux >= 604326b41a6fb9b4a78b6179335decee0365cd8c < 35f5e70bdfa7432762ac4ffa75e5a7574ac5563e","Linux >= 604326b41a6fb9b4a78b6179335decee0365cd8c < 435f5aa4421782af197b98d8525263977be4af5c","Linux >= 604326b41a6fb9b4a78b6179335decee0365cd8c < 3f8ef65af927db247418d4e1db49164d7a158fc5","Linux 4.20"],"ssvc":{"exploitation":"none","automatable":"no","technicalImpact":"partial","timestamp":"2026-11-05T20:10:23.590619Z"},"published":"2025-09-18","updated":"2026-11-05","sourceUpdated":"2026-11-05T20:10:36.333Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2022-50409","references":[{"url":"https://git.kernel.org/stable/c/a76462dbdd8bddcbeec9463bc9e54e509b860762"},{"url":"https://git.kernel.org/stable/c/65029aaedd15d9fe5ea1a899134e236d83f627bb"},{"url":"https://git.kernel.org/stable/c/124b7c773271f06af5a2cea694b283cdb5275cf5"},{"url":"https://git.kernel.org/stable/c/35f5e70bdfa7432762ac4ffa75e5a7574ac5563e"},{"url":"https://git.kernel.org/stable/c/435f5aa4421782af197b98d8525263977be4af5c"},{"url":"https://git.kernel.org/stable/c/3f8ef65af927db247418d4e1db49164d7a158fc5"}],"tags":["cve.org"],"epss":0.0016,"epssPercentile":0.05167,"ingestedAt":"2026-11-05T22:38:31.729Z","slug":"CVE-2022-50409","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nnet: If sock is dead don't access sock's sk_wq in sk_stream_wait_memory\n\nFixes the below NULL pointer dereference:\n\n  [...]\n  [   14.471200] Call Trace:\n  [   14.471562]  <TASK>\n  [   14.471882]  lock_acquire+0x245/0x2e0\n  [   14.472416]  ? remove_wait_queue+0x12/0x50\n  [   14.473014]  ? _raw_spin_lock_irqsave+0x17/0x50\n  [   14.473681]  _raw_spin_lock_irqsave+0x3d/0x50\n  [   14.474318]  ? remove_wait_queue+0x12/0x50\n  [   14.474907]  remove_wait_queue+0x12/0x50\n  [   14.475480]  sk_stream_wait_memory+0x20d/0x340\n  [   14.476127]  ? do_wait_intr_irq+0x80/0x80\n  [   14.476704]  do_tcp_sendpages+0x287/0x600\n  [   14.477283]  tcp_bpf_push+0xab/0x260\n  [   14.477817]  tcp_bpf_sendmsg_redir+0x297/0x500\n  [   14.478461]  ? __local_bh_enable_ip+0x77/0xe0\n  [   14.479096]  tcp_bpf_send_verdict+0x105/0x470\n  [   14.479729]  tcp_bpf_sendmsg+0x318/0x4f0\n  [   14.480311]  sock_sendmsg+0x2d/0x40\n  [   14.480822]  ____sys_sendmsg+0x1b4/0x1c0\n  [   14.481390]  ? copy_msghdr_from_user+0x62/0x80\n  [   14.482048]  ___sys_sendmsg+0x78/0xb0\n  [   14.482580]  ? vmf_insert_pfn_prot+0x91/0x150\n  [   14.483215]  ? __do_fault+0x2a/0x1a0\n  [   14.483738]  ? do_fault+0x15e/0x5d0\n  [   14.484246]  ? __handle_mm_fault+0x56b/0x1040\n  [   14.484874]  ? lock_is_held_type+0xdf/0x130\n  [   14.485474]  ? find_held_lock+0x2d/0x90\n  [   14.486046]  ? __sys_sendmsg+0x41/0x70\n  [   14.486587]  __sys_sendmsg+0x41/0x70\n  [   14.487105]  ? intel_pmu_drain_pebs_core+0x350/0x350\n  [   14.487822]  do_syscall_64+0x34/0x80\n  [   14.488345]  entry_SYSCALL_64_after_hwframe+0x63/0xcd\n  [...]\n\nThe test scenario has the following flow:\n\nthread1                               thread2\n-----------                           ---------------\n tcp_bpf_sendmsg\n  tcp_bpf_send_verdict\n   tcp_bpf_sendmsg_redir              sock_close\n    tcp_bpf_push_locked                 __sock_release\n     tcp_bpf_push                         //inet_release\n      do_tcp_sendpages                    sock->ops->release\n       sk_stream_wait_memory          \t   // tcp_close\n          sk_wait_event                      sk->sk_prot->close\n           release_sock(__sk);\n            ***\n                                                lock_sock(sk);\n                                                  __tcp_close\n                                                    sock_orphan(sk)\n                                                      sk->sk_wq  = NULL\n                                                release_sock\n            ****\n           lock_sock(__sk);\n          remove_wait_queue(sk_sleep(sk), &wait);\n             sk_sleep(sk)\n             //NULL pointer dereference\n             &rcu_dereference_raw(sk->sk_wq)->wait\n\nWhile waiting for memory in thread1, the socket is released with its wait\nqueue because thread2 has closed it. This caused by tcp_bpf_send_verdict\ndidn't increase the f_count of psock->sk_redir->sk_socket->file in thread1.\n\nWe should check if SOCK_DEAD flag is set on wakeup in sk_stream_wait_memory\nbefore accessing the wait queue.\n\n## Affected\n\n- `Linux >= 604326b41a6fb9b4a78b6179335decee0365cd8c < a76462dbdd8bddcbeec9463bc9e54e509b860762`\n- `Linux >= 604326b41a6fb9b4a78b6179335decee0365cd8c < 65029aaedd15d9fe5ea1a899134e236d83f627bb`\n- `Linux >= 604326b41a6fb9b4a78b6179335decee0365cd8c < 124b7c773271f06af5a2cea694b283cdb5275cf5`\n- `Linux >= 604326b41a6fb9b4a78b6179335decee0365cd8c < 35f5e70bdfa7432762ac4ffa75e5a7574ac5563e`\n- `Linux >= 604326b41a6fb9b4a78b6179335decee0365cd8c < 435f5aa4421782af197b98d8525263977be4af5c`\n- `Linux >= 604326b41a6fb9b4a78b6179335decee0365cd8c < 3f8ef65af927db247418d4e1db49164d7a158fc5`\n- `Linux 4.20`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"sunlit","depthScore":3,"depthScoreParts":{"impact":2.8,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}