{"id":"CVE-2026-74692","revision":"d8b519d2dfca46b1a57ad6b70713844c","records":[{"revision":"d8b519d2dfca46b1a57ad6b70713844c","observedAt":"2026-10-23T15:48:27.903+00:00","statement":{"source":"cve-program","id":"CVE-2026-74692","aliases":[],"title":"net/smc: fix TOCTOU race between smc_listen_out() and listener close","description":"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() 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.","state":0,"publishedAt":"2026-08-22T15:32:55.873+00:00","modifiedAt":"2026-10-16T19:16:09.513+00:00","affected":[{"ecosystem":"Vendor product","name":"Linux","ranges":[],"versions":[],"rawVersionEvidence":"{\n \"product\": \"Linux\",\n \"vendor\": \"Linux\",\n \"defaultStatus\": \"unaffected\",\n \"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\n \"programFiles\": [\n \"net/smc/af_smc.c\"\n ],\n \"versions\": [\n {\n \"version\": \"fd57770dd198f5b2ddd5b9e6bf282cf98d63adb9\",\n \"lessThan\": \"53c7938d8bcfde3296ec1a347ba2a9393c1fdcfa\",\n \"status\": \"affected\",\n \"versionType\": \"git\"\n },\n {\n \"version\": \"fd57770dd198f5b2ddd5b9e6bf282cf98d63adb9\",\n \"lessThan\": \"feb71634bb1abab3e8fb5cde874b27001cc1282e\",\n \"status\": \"affected\",\n \"versionType\": \"git\"\n },\n {\n \"version\": \"fd57770dd198f5b2ddd5b9e6bf282cf98d63adb9\",\n \"lessThan\": \"01865e1ddb126b25ac9eba5cdd7ec49e11183a64\",\n \"status\": \"affected\",\n \"versionType\": \"git\"\n },\n {\n \"version\": \"fd57770dd198f5b2ddd5b9e6bf282cf98d63adb9\",\n \"lessThan\": \"00f89433777236ced4771211047fb5d4cd581cea\",\n \"status\": \"affected\",\n \"versionType\": \"git\"\n },\n {\n \"version\": \"fd57770dd198f5b2ddd5b9e6bf282cf98d63adb9\",\n \"lessThan\": \"78e5ebcd1c10ed7c8bda0a99e0abd5b62da86d67\",\n \"status\": \"affected\",\n \"versionType\": \"git\"\n },\n {\n \"version\": \"fd57770dd198f5b2ddd5b9e6bf282cf98d63adb9\",\n \"lessThan\": \"ff5bcd804b5bc5c64736b7d318c20e12ea9506b8\",\n \"status\": \"affected\",\n \"versionType\": \"git\"\n },\n {\n \"version\": \"fd57770dd198f5b2ddd5b9e6bf282cf98d63adb9\",\n \"lessThan\": \"185a4caeecabc150106deda1da170b09f2ad803f\",\n \"status\": \"affected\",\n \"versionType\": \"git\"\n },\n {\n \"version\": \"d1d004585b40c212b338fc8a40cbaaf230ea4703\",\n \"status\": \"affected\",\n \"versionType\": \"git\"\n },\n {\n \"version\": \"4.19.299\",\n \"lessThan\": \"4.20\",\n \"status\": \"affected\",\n \"versionType\": \"semver\"\n }\n ]\n }"},{"ecosystem":"Vendor product","name":"Linux","ranges":[],"versions":[],"rawVersionEvidence":"{\n \"product\": \"Linux\",\n \"vendor\": \"Linux\",\n \"defaultStatus\": \"affected\",\n \"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\n \"programFiles\": [\n \"net/smc/af_smc.c\"\n ],\n \"versions\": [\n {\n \"version\": \"5.1\",\n \"status\": \"affected\"\n },\n {\n \"version\": \"0\",\n \"lessThan\": \"5.1\",\n \"status\": \"unaffected\",\n \"versionType\": \"semver\"\n },\n {\n \"version\": \"5.15.216\",\n \"lessThanOrEqual\": \"5.15.*\",\n \"status\": \"unaffected\",\n \"versionType\": \"semver\"\n },\n {\n \"version\": \"6.1.183\",\n \"lessThanOrEqual\": \"6.1.*\",\n \"status\": \"unaffected\",\n \"versionType\": \"semver\"\n },\n {\n \"version\": \"6.6.152\",\n \"lessThanOrEqual\": \"6.6.*\",\n \"status\": \"unaffected\",\n \"versionType\": \"semver\"\n },\n {\n \"version\": \"6.12.104\",\n \"lessThanOrEqual\": \"6.12.*\",\n \"status\": \"unaffected\",\n \"versionType\": \"semver\"\n },\n {\n \"version\": \"6.18.45\",\n \"lessThanOrEqual\": \"6.18.*\",\n \"status\": \"unaffected\",\n \"versionType\": \"semver\"\n },\n {\n \"version\": \"7.1.9\",\n \"lessThanOrEqual\": \"7.1.*\",\n \"status\": \"unaffected\",\n \"versionType\": \"semver\"\n },\n {\n \"version\": \"7.2\",\n \"lessThanOrEqual\": \"*\",\n \"status\": \"unaffected\",\n \"versionType\": \"original_commit_for_fix\"\n }\n ]\n }"}],"metrics":[{"system":"CVSS 3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","score":7.5,"severity":"HIGH"}],"references":["https://git.kernel.org/stable/c/53c7938d8bcfde3296ec1a347ba2a9393c1fdcfa","https://git.kernel.org/stable/c/feb71634bb1abab3e8fb5cde874b27001cc1282e","https://git.kernel.org/stable/c/01865e1ddb126b25ac9eba5cdd7ec49e11183a64","https://git.kernel.org/stable/c/00f89433777236ced4771211047fb5d4cd581cea","https://git.kernel.org/stable/c/78e5ebcd1c10ed7c8bda0a99e0abd5b62da86d67","https://git.kernel.org/stable/c/ff5bcd804b5bc5c64736b7d318c20e12ea9506b8","https://git.kernel.org/stable/c/185a4caeecabc150106deda1da170b09f2ad803f"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-74692","license":"CVE Program Terms of Use","key":"cve-program:CVE-2026-74692","identifiers":["CVE-2026-74692"]},"retained":false,"historicalAffected":[]}],"coverage":[]}