net/smc: fix TOCTOU race between smc_listen_out() and listener close

MITRE NVD CVE.ORG JSON API

Summary

CVECVE-2026-74692
StatePUBLISHED
AssignerLinux
Source PriorityCVE Program / NVD first with legacy fallback
Published2026-08-22 16:16:43 UTC
Updated2026-08-22 16:16:43 UTC
DescriptionIn the Linux kernel, the following vulnerability has been resolved: net/smc: fix TOCTOU race between smc_listen_out() and listener close smc_listen_out() reads lsmc->sk.sk_state without the listener lock, then acquires lock_sock_nested() only after the check passes. This opens a window where smc_close_active() can transition the listener to SMC_CLOSED, call smc_close_cleanup_listen() to drain the accept queue, and release the lock, all between the lockless read and the delayed lock acquisition: smc_listen_work (smc_hs_wq) smc_close_active() ------------------------------- ------------------------- release_sock(child) if (sk_state == SMC_LISTEN) TRUE lock_sock(listener) sk_state = SMC_CLOSED smc_close_cleanup_listen() release_sock(listener) flush_work(tcp_listen_work) lock_sock_nested(listener) smc_accept_enqueue(listener, child) /* child enqueued on dead listener */ smc_close_active() flushes only tcp_listen_work. Work items already dispatched onto smc_hs_wq for the CLC handshake continue running unguarded. smc_accept_enqueue() takes a sock_hold() on the child that is never released, so the child smc_sock, its clcsock, and the reference all leak. A remote peer that opens TCP connections while the server calls close() can exhaust kernel memory. Move lock_sock_nested() to before the sk_state check so that the test and the enqueue are atomic under the listener lock.

Vendor Declared Affected Products

SourceVendorProductVersionPlatforms
CNA Linux Linux affected fd57770dd198f5b2ddd5b9e6bf282cf98d63adb9 53c7938d8bcfde3296ec1a347ba2a9393c1fdcfa git Not specified
CNA Linux Linux affected fd57770dd198f5b2ddd5b9e6bf282cf98d63adb9 feb71634bb1abab3e8fb5cde874b27001cc1282e git Not specified
CNA Linux Linux affected fd57770dd198f5b2ddd5b9e6bf282cf98d63adb9 01865e1ddb126b25ac9eba5cdd7ec49e11183a64 git Not specified
CNA Linux Linux affected fd57770dd198f5b2ddd5b9e6bf282cf98d63adb9 00f89433777236ced4771211047fb5d4cd581cea git Not specified
CNA Linux Linux affected fd57770dd198f5b2ddd5b9e6bf282cf98d63adb9 78e5ebcd1c10ed7c8bda0a99e0abd5b62da86d67 git Not specified
CNA Linux Linux affected fd57770dd198f5b2ddd5b9e6bf282cf98d63adb9 ff5bcd804b5bc5c64736b7d318c20e12ea9506b8 git Not specified
CNA Linux Linux affected fd57770dd198f5b2ddd5b9e6bf282cf98d63adb9 185a4caeecabc150106deda1da170b09f2ad803f git Not specified
CNA Linux Linux affected d1d004585b40c212b338fc8a40cbaaf230ea4703 git Not specified
CNA Linux Linux affected 4.19.299 4.20 semver Not specified
CNA Linux Linux affected 5.1 Not specified
CNA Linux Linux unaffected 5.1 semver Not specified
CNA Linux Linux unaffected 5.15.216 5.15.* semver Not specified
CNA Linux Linux unaffected 6.1.183 6.1.* semver Not specified
CNA Linux Linux unaffected 6.6.152 6.6.* semver Not specified
CNA Linux Linux unaffected 6.12.104 6.12.* semver Not specified
CNA Linux Linux unaffected 6.18.45 6.18.* semver Not specified
CNA Linux Linux unaffected 7.1.9 7.1.* semver Not specified
CNA Linux Linux unaffected 7.2 * original_commit_for_fix Not specified

References

ReferenceSourceLinkTags
git.kernel.org/stable/c/78e5ebcd1c10ed7c8bda0a99e0abd5b62da86d67 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org
git.kernel.org/stable/c/185a4caeecabc150106deda1da170b09f2ad803f 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org
git.kernel.org/stable/c/00f89433777236ced4771211047fb5d4cd581cea 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org
git.kernel.org/stable/c/ff5bcd804b5bc5c64736b7d318c20e12ea9506b8 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org
git.kernel.org/stable/c/feb71634bb1abab3e8fb5cde874b27001cc1282e 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org
git.kernel.org/stable/c/53c7938d8bcfde3296ec1a347ba2a9393c1fdcfa 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org
git.kernel.org/stable/c/01865e1ddb126b25ac9eba5cdd7ec49e11183a64 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org
CVE Program record CVE.ORG www.cve.org canonical
NVD vulnerability detail NVD nvd.nist.gov canonical, analysis

© CVE.report 2026

Use of this information constitutes acceptance for use in an AS IS condition. There are NO warranties, implied or otherwise, with regard to this information or its use. Any use of this information is at the user's risk. It is the responsibility of user to evaluate the accuracy, completeness or usefulness of any information, opinion, advice or other content. EACH USER WILL BE SOLELY RESPONSIBLE FOR ANY consequences of his or her direct or indirect use of this web site. ALL WARRANTIES OF ANY KIND ARE EXPRESSLY DISCLAIMED. This site will NOT BE LIABLE FOR ANY DIRECT, INDIRECT or any other kind of loss.

CVE, CWE, and OVAL are registred trademarks of The MITRE Corporation and the authoritative source of CVE content is MITRE's CVE web site. This site includes MITRE data granted under the following license.

Free CVE JSON API cve.report/api

CVE.report and Source URL Uptime Status status.cve.report