{ "schemaVersion": 1, "attribution": [ { "source": "CISA Known Exploited Vulnerabilities", "url": "https://www.cisa.gov/known-exploited-vulnerabilities-catalog", "licence": "US government work" }, { "source": "GitHub Advisory Database", "url": "https://github.com/advisories", "licence": "CC BY 4.0" }, { "source": "Have I Been Pwned", "url": "https://haveibeenpwned.com/", "licence": "CC BY 4.0" }, { "source": "CVE Program (CVE records)", "url": "https://www.cve.org/Legal/TermsOfUse", "licence": "CVE Terms of Use", "notice": "Copyright © 1999-2026, The MITRE Corporation. CVE is a trademark and the CVE logo is a registered trademark of The MITRE Corporation.", "terms": "CVE Usage: MITRE hereby grants you a perpetual, worldwide, non-exclusive, no-charge, royalty-free, irrevocable copyright license to reproduce, prepare derivative works of, publicly display, publicly perform, sublicense, and distribute Common Vulnerabilities and Exposures (CVE™). Any copy you make for such purposes is authorized provided that you reproduce MITRE's copyright designation and this license in any such copy." }, { "source": "FIRST EPSS", "url": "https://www.first.org/epss/", "licence": "free to use; FIRST requests attribution" } ], "record": { "id": "CVE-2026-74609", "sourceURL": "https://www.cve.org/CVERecord?id=CVE-2026-74609", "idYear": 2026, "status": "PUBLISHED", "publishedAt": "2026-08-22T15:31:56.054Z", "updatedAt": "2026-10-16T19:06:01.059Z", "importedAt": "2026-10-24T01:58:30.346Z", "snapshot": { "id": "cve_2026-10-24_midnight_baseline", "at": "2026-10-24T00:00:00.000Z", "source": "https://github.com/CVEProject/cvelistV5/releases/tag/cve_2026-10-24_0100Z" }, "facts": { "title": "tipc: read le->link under the node lock in tipc_node_link_down()", "summary": "In the Linux kernel, the following vulnerability has been resolved:\n\ntipc: read le->link under the node lock in tipc_node_link_down()\n\ntipc_node_link_down() caches the link pointer before taking n->lock:\n\n\tstruct tipc_link *l = le->link;\t\t/* unlocked */\n\n\tif (!l)\n\t\treturn;\n\ttipc_node_write_lock(n);\n\tif (!tipc_link_is_establishing(l)) {\t/* deref l */\n\t...\n\t\ttipc_link_reset(l);\t\t/* write into l */\n\tif (delete) {\n\t\tkfree(l);\n\t\tle->link = NULL;\n\nThe delete=true caller frees that very object under n->lock, so the lock\ndoes not protect the cached pointer against it:\n\n - CPU A, delete=false: tipc_rcv() on TIPC_LINK_DOWN_EVT, or the link\n supervision timer via tipc_node_timeout(), reads l unlocked and then\n dereferences it under n->lock;\n - CPU B, delete=true: netlink TIPC_NL_BEARER_DISABLE -> bearer_disable()\n -> tipc_node_delete_links() -> tipc_node_link_down(n, bearer_id, true)\n -> kfree(l).\n\nThe link is freed with plain kfree(), not kfree_rcu(), and for UDP bearers\ndisable_media() only schedules the asynchronous cleanup_bearer() work, so\nits synchronize_net() runs after the links are already gone. An in-flight\nCPU A that has read l therefore dereferences freed memory once B frees it:\na use-after-free read in tipc_link_is_establishing(), and a use-after-free\nwrite via tipc_link_reset() on the establishing branch.\n\nThe following trace was captured on 7.2.0-rc5-00284-gaf39eb111ce6:\n\n BUG: KASAN: slab-use-after-free in tipc_link_is_establishing (net/tipc/link.c:285)\n Read of size 4 at addr ffff88802e2aa068 by task swapper/2/0\n tipc_link_is_establishing (net/tipc/link.c:285)\n tipc_node_link_down (net/tipc/node.c:1076)\n tipc_node_timeout (net/tipc/node.c:843)\n Allocated by task 9549:\n tipc_link_create (net/tipc/link.c:490)\n tipc_node_check_dest (net/tipc/node.c:1279)\n tipc_disc_rcv (net/tipc/discover.c:252)\n tipc_udp_recv (net/tipc/udp_media.c:389)\n Freed by task 9549:\n tipc_node_link_down (net/tipc/node.c:1084)\n tipc_node_delete_links (net/tipc/node.c:1320)\n bearer_disable (net/tipc/bearer.c:414)\n __tipc_nl_bearer_disable (net/tipc/bearer.c:992)\n\nMove the le->link read inside tipc_node_write_lock(), so it is serialised\nagainst the kfree() in the delete path. A racing teardown now either has\nnot run yet, and we see a valid link, or has already run, and we see NULL.", "affected": [ { "vendor": "Linux", "product": "Linux", "defaultStatus": "unaffected", "versions": [ { "version": "73f646cec35477b5099d7e952297cb9e1855be45", "status": "affected", "versionType": "git", "lessThan": "2be741ad565c610871a6a95062c12c39da7168fd" }, { "version": "73f646cec35477b5099d7e952297cb9e1855be45", "status": "affected", "versionType": "git", "lessThan": "69d209461c110388710e483a130caf051e4fd09a" }, { "version": "73f646cec35477b5099d7e952297cb9e1855be45", "status": "affected", "versionType": "git", "lessThan": "de017c22135f545ca4e65d1eada22887b64958eb" }, { "version": "73f646cec35477b5099d7e952297cb9e1855be45", "status": "affected", "versionType": "git", "lessThan": "47ba70891b10b2feb52462086b7fcd2ad75d3ce3" }, { "version": "73f646cec35477b5099d7e952297cb9e1855be45", "status": "affected", "versionType": "git", "lessThan": "a714d62513befef37f71f4ae89bb1fe173b65f2e" }, { "version": "73f646cec35477b5099d7e952297cb9e1855be45", "status": "affected", "versionType": "git", "lessThan": "c3f2347a47754eac690967cfd82cb6d559817b07" }, { "version": "73f646cec35477b5099d7e952297cb9e1855be45", "status": "affected", "versionType": "git", "lessThan": "5558a8312452ddb21eff22b1cbd84302ad951944" }, { "version": "73f646cec35477b5099d7e952297cb9e1855be45", "status": "affected", "versionType": "git", "lessThan": "cba9ccb47e9fa4cc77692fb896cc5ab57a667882" } ] }, { "vendor": "Linux", "product": "Linux", "defaultStatus": "affected", "versions": [ { "version": "4.4", "status": "affected" }, { "version": "0", "status": "unaffected", "versionType": "semver", "lessThan": "4.4" }, { "version": "5.10.265", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "5.10.*" }, { "version": "5.15.216", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "5.15.*" }, { "version": "6.1.183", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "6.1.*" }, { "version": "6.6.152", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "6.6.*" }, { "version": "6.12.104", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "6.12.*" }, { "version": "6.18.45", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "6.18.*" }, { "version": "7.1.9", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "7.1.*" }, { "version": "7.2", "status": "unaffected", "versionType": "original_commit_for_fix", "lessThanOrEqual": "*" } ] } ] } } }