CVE-2026-74692

{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-74692", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-08-15T05:44:03.926Z", "datePublished": "2026-08-22T15:32:55.873Z", "dateUpdated": "2026-10-16T19:16:09.513Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-25T05:41:37.608Z"}, "descriptions": [{"lang": "en", "value": "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."}], "metrics": [{"cvssV3_1": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H", "baseScore": 7.5, "baseSeverity": "HIGH"}, "scenarios": [{"lang": "en", "value": "AV:N - The bug fires when smc_listen_work() on smc_hs_wq finishes an inbound SMC/TCP handshake queued by smc_tcp_listen_work() for each remote connection to an AF_SMC listener, so any network peer that reaches the listener port drives the full path via SYN and CLC messages.\nAC:L - The attacker controls handshake completions by flooding SMC-capable TCP connections and overlapping them with listener close(), either by timing floods against restarts or locally by running server and client together; smc_close_active() only flushes tcp_listen_work, leaving smc_hs_wq workers racing through the unlocked sk_state check.\nPR:N - SMC performs no authentication; smc_create() and smc_listen() enforce no capabilities, and smc_listen_work() processes the CLC handshake immediately after TCP accept before any credential verification, so an unauthenticated remote peer need only reach the listener port.\nUI:N - Exploitation requires only inbound network connections and kernel handshake/close processing; no end-user action such as opening a file or mounting a filesystem is needed, and listener shutdown during deployments or restarts is routine automated server behavior.\nS:U - The leak accumulates orphaned smc_sock structures and clcsock references within the kernel networking subsystem on the targeted host; it does not cross VM, container, IOMMU, or other security boundaries.\nC:N - The bug is an unreleased sock_hold() leaving child sockets on a closed listener accept queue; objects are never freed prematurely, so there is no out-of-bounds read, use-after-free dereference, or kernel data disclosure to the attacker.\nI:N - Only reference counts are incremented without matching decrements; no memory is written out of bounds, no freed object is reused, and no control-flow or integrity primitive is obtained\u2014only unreclaimable kernel allocations accumulate.\nA:H - Each successful race permanently leaks a child smc_sock, its clcsock, and sock references that smc_close_cleanup_listen() can never drain; a remote peer repeating handshakes during listener close can exhaust kernel memory and cause system-wide denial of service."}]}], "affected": [{"product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["net/smc/af_smc.c"], "versions": [{"version": "fd57770dd198f5b2ddd5b9e6bf282cf98d63adb9", "lessThan": "53c7938d8bcfde3296ec1a347ba2a9393c1fdcfa", "status": "affected", "versionType": "git"}, {"version": "fd57770dd198f5b2ddd5b9e6bf282cf98d63adb9", "lessThan": "feb71634bb1abab3e8fb5cde874b27001cc1282e", "status": "affected", "versionType": "git"}, {"version": "fd57770dd198f5b2ddd5b9e6bf282cf98d63adb9", "lessThan": "01865e1ddb126b25ac9eba5cdd7ec49e11183a64", "status": "affected", "versionType": "git"}, {"version": "fd57770dd198f5b2ddd5b9e6bf282cf98d63adb9", "lessThan": "00f89433777236ced4771211047fb5d4cd581cea", "status": "affected", "versionType": "git"}, {"version": "fd57770dd198f5b2ddd5b9e6bf282cf98d63adb9", "lessThan": "78e5ebcd1c10ed7c8bda0a99e0abd5b62da86d67", "status": "affected", "versionType": "git"}, {"version": "fd57770dd198f5b2ddd5b9e6bf282cf98d63adb9", "lessThan": "ff5bcd804b5bc5c64736b7d318c20e12ea9506b8", "status": "affected", "versionType": "git"}, {"version": "fd57770dd198f5b2ddd5b9e6bf282cf98d63adb9", "lessThan": "185a4caeecabc150106deda1da170b09f2ad803f", "status": "affected", "versionType": "git"}, {"version": "d1d004585b40c212b338fc8a40cbaaf230ea4703", "status": "affected", "versionType": "git"}, {"version": "4.19.299", "lessThan": "4.20", "status": "affected", "versionType": "semver"}]}, {"product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["net/smc/af_smc.c"], "versions": [{"version": "5.1", "status": "affected"}, {"version": "0", "lessThan": "5.1", "status": "unaffected", "versionType": "semver"}, {"version": "5.15.216", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.1.183", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.6.152", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.12.104", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.18.45", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver"}, {"version": "7.1.9", "lessThanOrEqual": "7.1.*", "status": "unaffected", "versionType": "semver"}, {"version": "7.2", "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": "5.1", "versionEndExcluding": "5.15.216"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.1", "versionEndExcluding": "6.1.183"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.1", "versionEndExcluding": "6.6.152"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.1", "versionEndExcluding": "6.12.104"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.1", "versionEndExcluding": "6.18.45"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.1", "versionEndExcluding": "7.1.9"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.1", "versionEndExcluding": "7.2"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.19.299"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/53c7938d8bcfde3296ec1a347ba2a9393c1fdcfa"}, {"url": "https://git.kernel.org/stable/c/feb71634bb1abab3e8fb5cde874b27001cc1282e"}, {"url": "https://git.kernel.org/stable/c/01865e1ddb126b25ac9eba5cdd7ec49e11183a64"}, {"url": "https://git.kernel.org/stable/c/00f89433777236ced4771211047fb5d4cd581cea"}, {"url": "https://git.kernel.org/stable/c/78e5ebcd1c10ed7c8bda0a99e0abd5b62da86d67"}, {"url": "https://git.kernel.org/stable/c/ff5bcd804b5bc5c64736b7d318c20e12ea9506b8"}, {"url": "https://git.kernel.org/stable/c/185a4caeecabc150106deda1da170b09f2ad803f"}], "title": "net/smc: fix TOCTOU race between smc_listen_out() and listener close", "x_generator": {"engine": "bippy-1.2.0"}}, "adp": [{"metrics": [{"other": {"type": "ssvc", "content": {"id": "CVE-2026-74692", "role": "CISA Coordinator", "options": [{"Exploitation": "none"}, {"Automatable": "yes"}, {"Technical Impact": "partial"}], "version": "2.0.3", "timestamp": "2026-10-16T19:14:39.954097Z"}}}], "title": "CISA ADP Vulnrichment", "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-10-16T19:16:09.513Z"}}]}}

{"dataType": "CVE_RECORD", "containers": {"adp": [{"title": "CISA ADP Vulnrichment", "metrics": [{"other": {"type": "ssvc", "content": {"id": "CVE-2026-74692", "role": "CISA Coordinator", "options": [{"Exploitation": "none"}, {"Automatable": "yes"}, {"Technical Impact": "partial"}], "version": "2.0.3", "timestamp": "2026-10-16T19:14:39.954097Z"}}}], "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-10-16T19:14:40.891Z"}}], "cna": {"title": "net/smc: fix TOCTOU race between smc_listen_out() and listener close", "metrics": [{"cvssV3_1": {"version": "3.1", "baseScore": 7.5, "baseSeverity": "HIGH", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"}, "scenarios": [{"lang": "en", "value": "AV:N - The bug fires when smc_listen_work() on smc_hs_wq finishes an inbound SMC/TCP handshake queued by smc_tcp_listen_work() for each remote connection to an AF_SMC listener, so any network peer that reaches the listener port drives the full path via SYN and CLC messages.\nAC:L - The attacker controls handshake completions by flooding SMC-capable TCP connections and overlapping them with listener close(), either by timing floods against restarts or locally by running server and client together; smc_close_active() only flushes tcp_listen_work, leaving smc_hs_wq workers racing through the unlocked sk_state check.\nPR:N - SMC performs no authentication; smc_create() and smc_listen() enforce no capabilities, and smc_listen_work() processes the CLC handshake immediately after TCP accept before any credential verification, so an unauthenticated remote peer need only reach the listener port.\nUI:N - Exploitation requires only inbound network connections and kernel handshake/close processing; no end-user action such as opening a file or mounting a filesystem is needed, and listener shutdown during deployments or restarts is routine automated server behavior.\nS:U - The leak accumulates orphaned smc_sock structures and clcsock references within the kernel networking subsystem on the targeted host; it does not cross VM, container, IOMMU, or other security boundaries.\nC:N - The bug is an unreleased sock_hold() leaving child sockets on a closed listener accept queue; objects are never freed prematurely, so there is no out-of-bounds read, use-after-free dereference, or kernel data disclosure to the attacker.\nI:N - Only reference counts are incremented without matching decrements; no memory is written out of bounds, no freed object is reused, and no control-flow or integrity primitive is obtained\u2014only unreclaimable kernel allocations accumulate.\nA:H - Each successful race permanently leaks a child smc_sock, its clcsock, and sock references that smc_close_cleanup_listen() can never drain; a remote peer repeating handshakes during listener close can exhaust kernel memory and cause system-wide denial of service."}]}], "affected": [{"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "product": "Linux", "versions": [{"status": "affected", "version": "fd57770dd198f5b2ddd5b9e6bf282cf98d63adb9", "lessThan": "53c7938d8bcfde3296ec1a347ba2a9393c1fdcfa", "versionType": "git"}, {"status": "affected", "version": "fd57770dd198f5b2ddd5b9e6bf282cf98d63adb9", "lessThan": "feb71634bb1abab3e8fb5cde874b27001cc1282e", "versionType": "git"}, {"status": "affected", "version": "fd57770dd198f5b2ddd5b9e6bf282cf98d63adb9", "lessThan": "01865e1ddb126b25ac9eba5cdd7ec49e11183a64", "versionType": "git"}, {"status": "affected", "version": "fd57770dd198f5b2ddd5b9e6bf282cf98d63adb9", "lessThan": "00f89433777236ced4771211047fb5d4cd581cea", "versionType": "git"}, {"status": "affected", "version": "fd57770dd198f5b2ddd5b9e6bf282cf98d63adb9", "lessThan": "78e5ebcd1c10ed7c8bda0a99e0abd5b62da86d67", "versionType": "git"}, {"status": "affected", "version": "fd57770dd198f5b2ddd5b9e6bf282cf98d63adb9", "lessThan": "ff5bcd804b5bc5c64736b7d318c20e12ea9506b8", "versionType": "git"}, {"status": "affected", "version": "fd57770dd198f5b2ddd5b9e6bf282cf98d63adb9", "lessThan": "185a4caeecabc150106deda1da170b09f2ad803f", "versionType": "git"}, {"status": "affected", "version": "d1d004585b40c212b338fc8a40cbaaf230ea4703", "versionType": "git"}, {"status": "affected", "version": "4.19.299", "lessThan": "4.20", "versionType": "semver"}], "programFiles": ["net/smc/af_smc.c"], "defaultStatus": "unaffected"}, {"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "product": "Linux", "versions": [{"status": "affected", "version": "5.1"}, {"status": "unaffected", "version": "0", "lessThan": "5.1", "versionType": "semver"}, {"status": "unaffected", "version": "5.15.216", "versionType": "semver", "lessThanOrEqual": "5.15.*"}, {"status": "unaffected", "version": "6.1.183", "versionType": "semver", "lessThanOrEqual": "6.1.*"}, {"status": "unaffected", "version": "6.6.152", "versionType": "semver", "lessThanOrEqual": "6.6.*"}, {"status": "unaffected", "version": "6.12.104", "versionType": "semver", "lessThanOrEqual": "6.12.*"}, {"status": "unaffected", "version": "6.18.45", "versionType": "semver", "lessThanOrEqual": "6.18.*"}, {"status": "unaffected", "version": "7.1.9", "versionType": "semver", "lessThanOrEqual": "7.1.*"}, {"status": "unaffected", "version": "7.2", "versionType": "original_commit_for_fix", "lessThanOrEqual": "*"}], "programFiles": ["net/smc/af_smc.c"], "defaultStatus": "affected"}], "references": [{"url": "https://git.kernel.org/stable/c/53c7938d8bcfde3296ec1a347ba2a9393c1fdcfa"}, {"url": "https://git.kernel.org/stable/c/feb71634bb1abab3e8fb5cde874b27001cc1282e"}, {"url": "https://git.kernel.org/stable/c/01865e1ddb126b25ac9eba5cdd7ec49e11183a64"}, {"url": "https://git.kernel.org/stable/c/00f89433777236ced4771211047fb5d4cd581cea"}, {"url": "https://git.kernel.org/stable/c/78e5ebcd1c10ed7c8bda0a99e0abd5b62da86d67"}, {"url": "https://git.kernel.org/stable/c/ff5bcd804b5bc5c64736b7d318c20e12ea9506b8"}, {"url": "https://git.kernel.org/stable/c/185a4caeecabc150106deda1da170b09f2ad803f"}], "x_generator": {"engine": "bippy-1.2.0"}, "descriptions": [{"lang": "en", "value": "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."}], "cpeApplicability": [{"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "versionEndExcluding": "5.15.216", "versionStartIncluding": "5.1"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "versionEndExcluding": "6.1.183", "versionStartIncluding": "5.1"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "versionEndExcluding": "6.6.152", "versionStartIncluding": "5.1"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "versionEndExcluding": "6.12.104", "versionStartIncluding": "5.1"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "versionEndExcluding": "6.18.45", "versionStartIncluding": "5.1"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "versionEndExcluding": "7.1.9", "versionStartIncluding": "5.1"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "versionEndExcluding": "7.2", "versionStartIncluding": "5.1"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "versionStartIncluding": "4.19.299"}], "operator": "OR"}]}], "providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-25T05:41:37.608Z"}}}, "cveMetadata": {"cveId": "CVE-2026-74692", "state": "PUBLISHED", "dateUpdated": "2026-10-16T19:16:09.513Z", "dateReserved": "2026-08-15T05:44:03.926Z", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "datePublished": "2026-08-22T15:32:55.873Z", "assignerShortName": "Linux"}, "dataVersion": "5.2"}

{"affected": [{"affectedData": [{"defaultStatus": "unaffected", "product": "Linux", "programFiles": ["net/smc/af_smc.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"lessThan": "53c7938d8bcfde3296ec1a347ba2a9393c1fdcfa", "status": "affected", "version": "fd57770dd198f5b2ddd5b9e6bf282cf98d63adb9", "versionType": "git"}, {"lessThan": "feb71634bb1abab3e8fb5cde874b27001cc1282e", "status": "affected", "version": "fd57770dd198f5b2ddd5b9e6bf282cf98d63adb9", "versionType": "git"}, {"lessThan": "01865e1ddb126b25ac9eba5cdd7ec49e11183a64", "status": "affected", "version": "fd57770dd198f5b2ddd5b9e6bf282cf98d63adb9", "versionType": "git"}, {"lessThan": "00f89433777236ced4771211047fb5d4cd581cea", "status": "affected", "version": "fd57770dd198f5b2ddd5b9e6bf282cf98d63adb9", "versionType": "git"}, {"lessThan": "78e5ebcd1c10ed7c8bda0a99e0abd5b62da86d67", "status": "affected", "version": "fd57770dd198f5b2ddd5b9e6bf282cf98d63adb9", "versionType": "git"}, {"lessThan": "ff5bcd804b5bc5c64736b7d318c20e12ea9506b8", "status": "affected", "version": "fd57770dd198f5b2ddd5b9e6bf282cf98d63adb9", "versionType": "git"}, {"lessThan": "185a4caeecabc150106deda1da170b09f2ad803f", "status": "affected", "version": "fd57770dd198f5b2ddd5b9e6bf282cf98d63adb9", "versionType": "git"}, {"status": "affected", "version": "d1d004585b40c212b338fc8a40cbaaf230ea4703", "versionType": "git"}, {"lessThan": "4.20", "status": "affected", "version": "4.19.299", "versionType": "semver"}]}, {"defaultStatus": "affected", "product": "Linux", "programFiles": ["net/smc/af_smc.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"status": "affected", "version": "5.1"}, {"lessThan": "5.1", "status": "unaffected", "version": "0", "versionType": "semver"}, {"lessThanOrEqual": "5.15.*", "status": "unaffected", "version": "5.15.216", "versionType": "semver"}, {"lessThanOrEqual": "6.1.*", "status": "unaffected", "version": "6.1.183", "versionType": "semver"}, {"lessThanOrEqual": "6.6.*", "status": "unaffected", "version": "6.6.152", "versionType": "semver"}, {"lessThanOrEqual": "6.12.*", "status": "unaffected", "version": "6.12.104", "versionType": "semver"}, {"lessThanOrEqual": "6.18.*", "status": "unaffected", "version": "6.18.45", "versionType": "semver"}, {"lessThanOrEqual": "7.1.*", "status": "unaffected", "version": "7.1.9", "versionType": "semver"}, {"lessThanOrEqual": "*", "status": "unaffected", "version": "7.2", "versionType": "original_commit_for_fix"}]}], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}], "cveTags": [], "descriptions": [{"lang": "en", "value": "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."}, {"lang": "es", "value": "En el kernel de Linux, la siguiente vulnerabilidad ha sido resuelta:\n\nnet/smc: corrige la condici\u00f3n de carrera TOCTOU entre smc_listen_out() y el cierre del oyente\n\nsmc_listen_out() lee lsmc -> sk.sk_state sin el bloqueo del oyente, luego adquiere lock_sock_nested() solo despu\u00e9s de que la verificaci\u00f3n pasa. Esto abre una ventana donde smc_close_active() puede hacer la transici\u00f3n del oyente a SMC_CLOSED, llamar a smc_close_cleanup_listen() para vaciar la cola de aceptaci\u00f3n y liberar el bloqueo, todo entre la lectura sin bloqueo y la adquisici\u00f3n de bloqueo retrasada:\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) /* hijo encolado en oyente inactivo */\n\nsmc_close_active() vac\u00eda solo tcp_listen_work. Los elementos de trabajo ya despachados a smc_hs_wq para el handshake CLC contin\u00faan ejecut\u00e1ndose sin protecci\u00f3n. smc_accept_enqueue() toma un sock_hold() en el hijo que nunca se libera, por lo que el smc_sock hijo, su clcsock y la referencia se filtran. Un par remoto que abre conexiones TCP mientras el servidor llama a close() puede agotar la memoria del kernel.\n\nMover lock_sock_nested() a antes de la verificaci\u00f3n de sk_state para que la prueba y la encolaci\u00f3n sean at\u00f3micas bajo el bloqueo del oyente."}], "id": "CVE-2026-74692", "lastModified": "2026-10-16T20:17:52.133", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "LOW", "attackVector": "NETWORK", "availabilityImpact": "HIGH", "baseScore": 7.5, "baseSeverity": "HIGH", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "privilegesRequired": "NONE", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H", "version": "3.1"}, "exploitabilityScore": 3.9, "impactScore": 3.6, "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "type": "Secondary"}], "ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2026-74692", "options": [{"exploitation": "none"}, {"automatable": "yes"}, {"technicalImpact": "partial"}], "role": "CISA Coordinator", "timestamp": "2026-10-16T19:14:39.954097Z", "version": "2.0.3"}}]}, "published": "2026-08-22T16:16:43.667", "references": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/00f89433777236ced4771211047fb5d4cd581cea"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/01865e1ddb126b25ac9eba5cdd7ec49e11183a64"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/185a4caeecabc150106deda1da170b09f2ad803f"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/53c7938d8bcfde3296ec1a347ba2a9393c1fdcfa"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/78e5ebcd1c10ed7c8bda0a99e0abd5b62da86d67"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/feb71634bb1abab3e8fb5cde874b27001cc1282e"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/ff5bcd804b5bc5c64736b7d318c20e12ea9506b8"}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "vulnStatus": "Received"}

{"bugzilla": {"description": "kernel: net/smc: fix TOCTOU race between smc_listen_out() and listener close", "id": "2521496", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2521496"}, "csaw": false, "cvss3": {"cvss3_base_score": "7.0", "cvss3_scoring_vector": "CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H", "status": "draft"}, "cwe": "CWE-367", "details": ["In the Linux kernel, the following vulnerability has been resolved:\nnet/smc: fix TOCTOU race between smc_listen_out() and listener close\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:\nsmc_listen_work (smc_hs_wq) smc_close_active()\n------------------------------- -------------------------\nrelease_sock(child)\nif (sk_state == SMC_LISTEN) TRUE\nlock_sock(listener)\nsk_state = SMC_CLOSED\nsmc_close_cleanup_listen()\nrelease_sock(listener)\nflush_work(tcp_listen_work)\nlock_sock_nested(listener)\nsmc_accept_enqueue(listener, child) /* child enqueued on dead listener */\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.\nMove lock_sock_nested() to before the sk_state check so that the test\nand the enqueue are atomic under the listener lock.", "A flaw was found in the Linux kernel's `net/smc` component. A time-of-check to time-of-use (TOCTOU) race condition allows a remote attacker to exploit a window where the listener's state is checked without proper locking. By opening TCP connections while the server is closing, an attacker can cause a memory leak. This can lead to kernel memory exhaustion and a Denial of Service (DoS) for the system."], "name": "CVE-2026-74692", "package_state": [{"cpe": "cpe:/o:redhat:enterprise_linux:10", "fix_state": "Affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 10"}, {"cpe": "cpe:/o:redhat:enterprise_linux:6", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 6"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Not affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 9"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 9"}], "public_date": "2026-08-22T00:00:00Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2026-74692\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-74692\nhttps://lore.kernel.org/linux-cve-announce/2026082234-CVE-2026-74692-bf74@gregkh/T"], "threat_severity": "Moderate"}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[fd57770dd198f5b2ddd5b9e6bf282cf98d63adb9,53c7938d8bcfde3296ec1a347ba2a9393c1fdcfa]"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[fd57770dd198f5b2ddd5b9e6bf282cf98d63adb9,feb71634bb1abab3e8fb5cde874b27001cc1282e]"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[fd57770dd198f5b2ddd5b9e6bf282cf98d63adb9,01865e1ddb126b25ac9eba5cdd7ec49e11183a64]"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[fd57770dd198f5b2ddd5b9e6bf282cf98d63adb9,00f89433777236ced4771211047fb5d4cd581cea]"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[fd57770dd198f5b2ddd5b9e6bf282cf98d63adb9,78e5ebcd1c10ed7c8bda0a99e0abd5b62da86d67]"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[fd57770dd198f5b2ddd5b9e6bf282cf98d63adb9,ff5bcd804b5bc5c64736b7d318c20e12ea9506b8]"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[fd57770dd198f5b2ddd5b9e6bf282cf98d63adb9,185a4caeecabc150106deda1da170b09f2ad803f]"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "d1d004585b40c212b338fc8a40cbaaf230ea4703"}}, {"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "[4.19.299,4.20)"}}], "enrichment": {"confidence": 99.0, "confidence_source": "inferred", "scores": [{"score": 99.0, "source": "inferred"}, {"score": 100.0, "source": "matching"}]}, "original": {"product": "Linux", "source": "cna", "vendor": "Linux"}, "product": "linux_kernel", "vendor": "linux"}, {"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "generic", "value": "5.1"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[0,5.1)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[5.15.216,5.15.*]"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[6.1.183,6.1.*]"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[6.6.152,6.6.*]"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[6.12.104,6.12.*]"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[6.18.45,6.18.*]"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[7.1.9,7.1.*]"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "generic", "value": "[7.2,*]"}}], "enrichment": {"confidence": 99.0, "confidence_source": "inferred", "scores": [{"score": 99.0, "source": "inferred"}, {"score": 100.0, "source": "matching"}]}, "original": {"product": "Linux", "source": "cna", "vendor": "Linux"}, "product": "linux_kernel", "vendor": "linux"}], "created": "2026-08-22T17:30:02.931243+00:00", "updated": "2026-08-25T16:30:06.098897+00:00", "vendors": ["linux", "linux$PRODUCT$linux_kernel"]}