{"id":"CVE-2026-74692","title":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet/smc: fix TOCTOU race between smc_listen_out() and listener close\n\nsmc_listen_out() reads lsmc->sk.sk_state without the listener lock,\nthen acquires lock_sock_nested…","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet/smc: fix TOCTOU race between smc_listen_out() and listener close\n\nsmc_listen_out() reads lsmc->sk.sk_state without the listener lock,\nthen acquires lock_sock_nested…","severity":"high","cvss":7.5,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","cwe":["CWE-401"],"vendor":"Linux","product":"Linux","affected":["Linux >= fd57770dd198f5b2ddd5b9e6bf282cf98d63adb9 < 53c7938d8bcfde3296ec1a347ba2a9393c1fdcfa","Linux >= fd57770dd198f5b2ddd5b9e6bf282cf98d63adb9 < feb71634bb1abab3e8fb5cde874b27001cc1282e","Linux >= fd57770dd198f5b2ddd5b9e6bf282cf98d63adb9 < 01865e1ddb126b25ac9eba5cdd7ec49e11183a64","Linux >= fd57770dd198f5b2ddd5b9e6bf282cf98d63adb9 < 00f89433777236ced4771211047fb5d4cd581cea","Linux >= fd57770dd198f5b2ddd5b9e6bf282cf98d63adb9 < 78e5ebcd1c10ed7c8bda0a99e0abd5b62da86d67","Linux >= fd57770dd198f5b2ddd5b9e6bf282cf98d63adb9 < ff5bcd804b5bc5c64736b7d318c20e12ea9506b8","Linux >= fd57770dd198f5b2ddd5b9e6bf282cf98d63adb9 < 185a4caeecabc150106deda1da170b09f2ad803f","Linux d1d004585b40c212b338fc8a40cbaaf230ea4703","Linux >= 4.19.299 < 4.20","Linux 5.1"],"published":"2026-08-22","updated":"2026-10-16","sourceUpdated":"2026-10-16T20:17:52.133","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-74692","references":[{"url":"https://git.kernel.org/stable/c/00f89433777236ced4771211047fb5d4cd581cea","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/01865e1ddb126b25ac9eba5cdd7ec49e11183a64","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/185a4caeecabc150106deda1da170b09f2ad803f","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/53c7938d8bcfde3296ec1a347ba2a9393c1fdcfa","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/78e5ebcd1c10ed7c8bda0a99e0abd5b62da86d67","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/feb71634bb1abab3e8fb5cde874b27001cc1282e","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/ff5bcd804b5bc5c64736b7d318c20e12ea9506b8","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-74692.json"},{"url":"https://access.redhat.com/security/cve/CVE-2026-74692"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2521496"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-74692"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-74692"},{"url":"https://kernelcve.org/list/?q=CVE-2026-74692"},{"url":"https://lore.kernel.org/linux-cve-announce/2026082234-CVE-2026-74692-bf74@gregkh/T"}],"tags":["nvd","cve.org","csaf","vex","red-hat"],"epss":0.0049,"epssPercentile":0.41925,"ssvc":{"exploitation":"none","automatable":"yes","technicalImpact":"partial","timestamp":"2026-10-16T19:14:39.954097Z"},"scores":{"nvd":7.5,"vendor":5.9},"ingestedAt":"2026-10-14T13:30:58.539Z","slug":"CVE-2026-74692","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nnet/smc: fix TOCTOU race between smc_listen_out() and listener close\n\nsmc_listen_out() reads lsmc->sk.sk_state without the listener lock,\nthen acquires lock_sock_nested() only after the check passes. This\nopens a window where smc_close_active() can transition the listener\nto SMC_CLOSED, call smc_close_cleanup_listen() to drain the accept\nqueue, and release the lock, all between the lockless read and the\ndelayed lock acquisition:\n\n  smc_listen_work (smc_hs_wq)          smc_close_active()\n  -------------------------------      -------------------------\n  release_sock(child)\n  if (sk_state == SMC_LISTEN) TRUE\n                                        lock_sock(listener)\n                                        sk_state = SMC_CLOSED\n                                        smc_close_cleanup_listen()\n                                        release_sock(listener)\n                                        flush_work(tcp_listen_work)\n  lock_sock_nested(listener)\n  smc_accept_enqueue(listener, child) /* child enqueued on dead listener */\n\nsmc_close_active() flushes only tcp_listen_work. Work items already\ndispatched onto smc_hs_wq for the CLC handshake continue running\nunguarded. smc_accept_enqueue() takes a sock_hold() on the child that\nis never released, so the child smc_sock, its clcsock, and the\nreference all leak. A remote peer that opens TCP connections while the\nserver calls close() can exhaust kernel memory.\n\nMove lock_sock_nested() to before the sk_state check so that the test\nand the enqueue are atomic under the listener lock.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.\n\n## Vendor advisories\n\n- **Red Hat VEX** · Moderate · affected: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 8, Red Hat Enterprise Linux 9 · no fix planned: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 8, Red Hat Enterprise Linux 9 · updated 2026-10-26 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-74692.json)","depth":"twilight","depthScore":41,"depthScoreParts":{"impact":41.3,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[]}