CVE-2026-74609

{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-74609", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-08-15T05:44:03.920Z", "datePublished": "2026-08-22T15:31:56.054Z", "dateUpdated": "2026-10-16T19:06:01.059Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-25T05:40:34.778Z"}, "descriptions": [{"lang": "en", "value": "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."}], "metrics": [{"cvssV3_1": {"version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H", "baseScore": 7.8, "baseSeverity": "HIGH"}, "scenarios": [{"lang": "en", "value": "AV:L - The UAF race requires the delete=true path (kfree) via TIPC_NL_BEARER_DISABLE/bearer_disable() or netns teardown, reachable only through local RTNL/genlink with CAP_NET_ADMIN; remote tipc_rcv() packets alone cannot free links and complete the race.\nAC:L - An attacker with CAP_NET_ADMIN controls both CPUs by scripting bearer disable/netns teardown while concurrently driving link-down events via TIPC traffic or link supervision timers; KASAN reproduced this reliably without uncontrollable victim timing.\nPR:L - Bearer disable and link deletion require CAP_NET_ADMIN (GENL_UNS_ADMIN_PERM on TIPC_NL_BEARER_DISABLE); tipc_genl_family is netns-aware, so unprivileged users obtain effective net-admin via user/network namespaces (unshare -Urn).\nUI:N - No victim interaction is required; the attacker scripts bearer teardown and concurrent TIPC link activity from their own processes without needing another user to mount, open files, or perform administrative actions.\nS:U - Slab UAF corrupts host kernel heap memory within the same kernel security authority; impact is kernel crash or local privilege escalation, not a VM, IOMMU, or cross-container sandbox boundary escape.\nC:H - Slab use-after-free read in tipc_link_is_establishing() dereferences freed tipc_link objects (KASAN-confirmed), enabling disclosure of freed kernel memory and supporting further heap exploitation primitives.\nI:H - On the establishing branch tipc_link_reset() performs multiple writes into the freed tipc_link structure, corrupting kernel heap metadata and adjacent objects in ways exploitable for arbitrary write and control-flow hijacking.\nA:H - KASAN-confirmed slab-use-after-free in tipc_node_link_down() causes kernel oops/panic (observed on swapper during tipc_node_timeout), and the race can be retriggered during bearer teardown loops for reliable 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/tipc/node.c"], "versions": [{"version": "73f646cec35477b5099d7e952297cb9e1855be45", "lessThan": "2be741ad565c610871a6a95062c12c39da7168fd", "status": "affected", "versionType": "git"}, {"version": "73f646cec35477b5099d7e952297cb9e1855be45", "lessThan": "69d209461c110388710e483a130caf051e4fd09a", "status": "affected", "versionType": "git"}, {"version": "73f646cec35477b5099d7e952297cb9e1855be45", "lessThan": "de017c22135f545ca4e65d1eada22887b64958eb", "status": "affected", "versionType": "git"}, {"version": "73f646cec35477b5099d7e952297cb9e1855be45", "lessThan": "47ba70891b10b2feb52462086b7fcd2ad75d3ce3", "status": "affected", "versionType": "git"}, {"version": "73f646cec35477b5099d7e952297cb9e1855be45", "lessThan": "a714d62513befef37f71f4ae89bb1fe173b65f2e", "status": "affected", "versionType": "git"}, {"version": "73f646cec35477b5099d7e952297cb9e1855be45", "lessThan": "c3f2347a47754eac690967cfd82cb6d559817b07", "status": "affected", "versionType": "git"}, {"version": "73f646cec35477b5099d7e952297cb9e1855be45", "lessThan": "5558a8312452ddb21eff22b1cbd84302ad951944", "status": "affected", "versionType": "git"}, {"version": "73f646cec35477b5099d7e952297cb9e1855be45", "lessThan": "cba9ccb47e9fa4cc77692fb896cc5ab57a667882", "status": "affected", "versionType": "git"}]}, {"product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["net/tipc/node.c"], "versions": [{"version": "4.4", "status": "affected"}, {"version": "0", "lessThan": "4.4", "status": "unaffected", "versionType": "semver"}, {"version": "5.10.265", "lessThanOrEqual": "5.10.*", "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": "4.4", "versionEndExcluding": "5.10.265"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.4", "versionEndExcluding": "5.15.216"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.4", "versionEndExcluding": "6.1.183"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.4", "versionEndExcluding": "6.6.152"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.4", "versionEndExcluding": "6.12.104"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.4", "versionEndExcluding": "6.18.45"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.4", "versionEndExcluding": "7.1.9"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.4", "versionEndExcluding": "7.2"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/2be741ad565c610871a6a95062c12c39da7168fd"}, {"url": "https://git.kernel.org/stable/c/69d209461c110388710e483a130caf051e4fd09a"}, {"url": "https://git.kernel.org/stable/c/de017c22135f545ca4e65d1eada22887b64958eb"}, {"url": "https://git.kernel.org/stable/c/47ba70891b10b2feb52462086b7fcd2ad75d3ce3"}, {"url": "https://git.kernel.org/stable/c/a714d62513befef37f71f4ae89bb1fe173b65f2e"}, {"url": "https://git.kernel.org/stable/c/c3f2347a47754eac690967cfd82cb6d559817b07"}, {"url": "https://git.kernel.org/stable/c/5558a8312452ddb21eff22b1cbd84302ad951944"}, {"url": "https://git.kernel.org/stable/c/cba9ccb47e9fa4cc77692fb896cc5ab57a667882"}], "title": "tipc: read le->link under the node lock in tipc_node_link_down()", "x_generator": {"engine": "bippy-1.2.0"}}, "adp": [{"metrics": [{"other": {"type": "ssvc", "content": {"id": "CVE-2026-74609", "role": "CISA Coordinator", "options": [{"Exploitation": "none"}, {"Automatable": "no"}, {"Technical Impact": "total"}], "version": "2.0.3", "timestamp": "2026-10-16T19:02:14.527164Z"}}}], "title": "CISA ADP Vulnrichment", "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-10-16T19:06:01.059Z"}}]}}

{"dataType": "CVE_RECORD", "containers": {"adp": [{"title": "CISA ADP Vulnrichment", "metrics": [{"other": {"type": "ssvc", "content": {"id": "CVE-2026-74609", "role": "CISA Coordinator", "options": [{"Exploitation": "none"}, {"Automatable": "no"}, {"Technical Impact": "total"}], "version": "2.0.3", "timestamp": "2026-10-16T19:02:14.527164Z"}}}], "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-10-16T19:02:15.565Z"}}], "cna": {"title": "tipc: read le->link under the node lock in tipc_node_link_down()", "metrics": [{"cvssV3_1": {"version": "3.1", "baseScore": 7.8, "baseSeverity": "HIGH", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H"}, "scenarios": [{"lang": "en", "value": "AV:L - The UAF race requires the delete=true path (kfree) via TIPC_NL_BEARER_DISABLE/bearer_disable() or netns teardown, reachable only through local RTNL/genlink with CAP_NET_ADMIN; remote tipc_rcv() packets alone cannot free links and complete the race.\nAC:L - An attacker with CAP_NET_ADMIN controls both CPUs by scripting bearer disable/netns teardown while concurrently driving link-down events via TIPC traffic or link supervision timers; KASAN reproduced this reliably without uncontrollable victim timing.\nPR:L - Bearer disable and link deletion require CAP_NET_ADMIN (GENL_UNS_ADMIN_PERM on TIPC_NL_BEARER_DISABLE); tipc_genl_family is netns-aware, so unprivileged users obtain effective net-admin via user/network namespaces (unshare -Urn).\nUI:N - No victim interaction is required; the attacker scripts bearer teardown and concurrent TIPC link activity from their own processes without needing another user to mount, open files, or perform administrative actions.\nS:U - Slab UAF corrupts host kernel heap memory within the same kernel security authority; impact is kernel crash or local privilege escalation, not a VM, IOMMU, or cross-container sandbox boundary escape.\nC:H - Slab use-after-free read in tipc_link_is_establishing() dereferences freed tipc_link objects (KASAN-confirmed), enabling disclosure of freed kernel memory and supporting further heap exploitation primitives.\nI:H - On the establishing branch tipc_link_reset() performs multiple writes into the freed tipc_link structure, corrupting kernel heap metadata and adjacent objects in ways exploitable for arbitrary write and control-flow hijacking.\nA:H - KASAN-confirmed slab-use-after-free in tipc_node_link_down() causes kernel oops/panic (observed on swapper during tipc_node_timeout), and the race can be retriggered during bearer teardown loops for reliable 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": "73f646cec35477b5099d7e952297cb9e1855be45", "lessThan": "2be741ad565c610871a6a95062c12c39da7168fd", "versionType": "git"}, {"status": "affected", "version": "73f646cec35477b5099d7e952297cb9e1855be45", "lessThan": "69d209461c110388710e483a130caf051e4fd09a", "versionType": "git"}, {"status": "affected", "version": "73f646cec35477b5099d7e952297cb9e1855be45", "lessThan": "de017c22135f545ca4e65d1eada22887b64958eb", "versionType": "git"}, {"status": "affected", "version": "73f646cec35477b5099d7e952297cb9e1855be45", "lessThan": "47ba70891b10b2feb52462086b7fcd2ad75d3ce3", "versionType": "git"}, {"status": "affected", "version": "73f646cec35477b5099d7e952297cb9e1855be45", "lessThan": "a714d62513befef37f71f4ae89bb1fe173b65f2e", "versionType": "git"}, {"status": "affected", "version": "73f646cec35477b5099d7e952297cb9e1855be45", "lessThan": "c3f2347a47754eac690967cfd82cb6d559817b07", "versionType": "git"}, {"status": "affected", "version": "73f646cec35477b5099d7e952297cb9e1855be45", "lessThan": "5558a8312452ddb21eff22b1cbd84302ad951944", "versionType": "git"}, {"status": "affected", "version": "73f646cec35477b5099d7e952297cb9e1855be45", "lessThan": "cba9ccb47e9fa4cc77692fb896cc5ab57a667882", "versionType": "git"}], "programFiles": ["net/tipc/node.c"], "defaultStatus": "unaffected"}, {"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "product": "Linux", "versions": [{"status": "affected", "version": "4.4"}, {"status": "unaffected", "version": "0", "lessThan": "4.4", "versionType": "semver"}, {"status": "unaffected", "version": "5.10.265", "versionType": "semver", "lessThanOrEqual": "5.10.*"}, {"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/tipc/node.c"], "defaultStatus": "affected"}], "references": [{"url": "https://git.kernel.org/stable/c/2be741ad565c610871a6a95062c12c39da7168fd"}, {"url": "https://git.kernel.org/stable/c/69d209461c110388710e483a130caf051e4fd09a"}, {"url": "https://git.kernel.org/stable/c/de017c22135f545ca4e65d1eada22887b64958eb"}, {"url": "https://git.kernel.org/stable/c/47ba70891b10b2feb52462086b7fcd2ad75d3ce3"}, {"url": "https://git.kernel.org/stable/c/a714d62513befef37f71f4ae89bb1fe173b65f2e"}, {"url": "https://git.kernel.org/stable/c/c3f2347a47754eac690967cfd82cb6d559817b07"}, {"url": "https://git.kernel.org/stable/c/5558a8312452ddb21eff22b1cbd84302ad951944"}, {"url": "https://git.kernel.org/stable/c/cba9ccb47e9fa4cc77692fb896cc5ab57a667882"}], "x_generator": {"engine": "bippy-1.2.0"}, "descriptions": [{"lang": "en", "value": "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."}], "cpeApplicability": [{"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "versionEndExcluding": "5.10.265", "versionStartIncluding": "4.4"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "versionEndExcluding": "5.15.216", "versionStartIncluding": "4.4"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "versionEndExcluding": "6.1.183", "versionStartIncluding": "4.4"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "versionEndExcluding": "6.6.152", "versionStartIncluding": "4.4"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "versionEndExcluding": "6.12.104", "versionStartIncluding": "4.4"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "versionEndExcluding": "6.18.45", "versionStartIncluding": "4.4"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "versionEndExcluding": "7.1.9", "versionStartIncluding": "4.4"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "versionEndExcluding": "7.2", "versionStartIncluding": "4.4"}], "operator": "OR"}]}], "providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-25T05:40:34.778Z"}}}, "cveMetadata": {"cveId": "CVE-2026-74609", "state": "PUBLISHED", "dateUpdated": "2026-10-16T19:06:01.059Z", "dateReserved": "2026-08-15T05:44:03.920Z", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "datePublished": "2026-08-22T15:31:56.054Z", "assignerShortName": "Linux"}, "dataVersion": "5.2"}

{"affected": [{"affectedData": [{"defaultStatus": "unaffected", "product": "Linux", "programFiles": ["net/tipc/node.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"lessThan": "2be741ad565c610871a6a95062c12c39da7168fd", "status": "affected", "version": "73f646cec35477b5099d7e952297cb9e1855be45", "versionType": "git"}, {"lessThan": "69d209461c110388710e483a130caf051e4fd09a", "status": "affected", "version": "73f646cec35477b5099d7e952297cb9e1855be45", "versionType": "git"}, {"lessThan": "de017c22135f545ca4e65d1eada22887b64958eb", "status": "affected", "version": "73f646cec35477b5099d7e952297cb9e1855be45", "versionType": "git"}, {"lessThan": "47ba70891b10b2feb52462086b7fcd2ad75d3ce3", "status": "affected", "version": "73f646cec35477b5099d7e952297cb9e1855be45", "versionType": "git"}, {"lessThan": "a714d62513befef37f71f4ae89bb1fe173b65f2e", "status": "affected", "version": "73f646cec35477b5099d7e952297cb9e1855be45", "versionType": "git"}, {"lessThan": "c3f2347a47754eac690967cfd82cb6d559817b07", "status": "affected", "version": "73f646cec35477b5099d7e952297cb9e1855be45", "versionType": "git"}, {"lessThan": "5558a8312452ddb21eff22b1cbd84302ad951944", "status": "affected", "version": "73f646cec35477b5099d7e952297cb9e1855be45", "versionType": "git"}, {"lessThan": "cba9ccb47e9fa4cc77692fb896cc5ab57a667882", "status": "affected", "version": "73f646cec35477b5099d7e952297cb9e1855be45", "versionType": "git"}]}, {"defaultStatus": "affected", "product": "Linux", "programFiles": ["net/tipc/node.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"status": "affected", "version": "4.4"}, {"lessThan": "4.4", "status": "unaffected", "version": "0", "versionType": "semver"}, {"lessThanOrEqual": "5.10.*", "status": "unaffected", "version": "5.10.265", "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\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."}, {"lang": "es", "value": "En el kernel de Linux, la siguiente vulnerabilidad ha sido resuelta:\n\ntipc: lee le -> link bajo el bloqueo del nodo en tipc_node_link_down()\n\ntipc_node_link_down() almacena en cach\u00e9 el puntero de enlace antes de tomar n -> lock:\n\n\tstruct tipc_link l = le -> link;\t\t/* desbloqueado */\n\n\tif (!l)\n\t\treturn;\n\ttipc_node_write_lock(n);\n\tif (!tipc_link_is_establishing(l)) {\t/* desreferencia l */\n\t...\n\t\ttipc_link_reset(l);\t\t/* escribe en l */\n\tif (delete) {\n\t\tkfree(l);\n\t\tle -> link = NULL;\n\nEl llamador con delete=true libera ese mismo objeto bajo n -> lock, por lo que el bloqueo no protege el puntero almacenado en cach\u00e9 contra ello:\n\n - CPU A, delete=false: tipc_rcv() en TIPC_LINK_DOWN_EVT, o el temporizador de supervisi\u00f3n de enlace a trav\u00e9s de tipc_node_timeout(), lee l desbloqueado y luego lo desreferencia bajo n -> lock;\n - CPU B, delete=true: netlink TIPC_NL_BEARER_DISABLE -> bearer_disable() -> tipc_node_delete_links() -> tipc_node_link_down(n, bearer_id, true) -> kfree(l).\n\nEl enlace se libera con kfree() simple, no con kfree_rcu(), y para los portadores UDP, disable_media() solo programa el trabajo as\u00edncrono cleanup_bearer(), por lo que su synchronize_net() se ejecuta despu\u00e9s de que los enlaces ya no existen. Una CPU A en vuelo que ha le\u00eddo l, por lo tanto, desreferencia memoria liberada una vez que B la libera: una lectura de uso despu\u00e9s de liberaci\u00f3n en tipc_link_is_establishing(), y una escritura de uso despu\u00e9s de liberaci\u00f3n a trav\u00e9s de tipc_link_reset() en la rama de establecimiento.\n\nLa siguiente traza fue capturada en 7.2.0-rc5-00284-gaf39eb111ce6:\n\n ERROR: KASAN: uso despu\u00e9s de liberaci\u00f3n de slab en tipc_link_is_establishing (net/tipc/link.c:285)\n Lectura de tama\u00f1o 4 en la direcci\u00f3n ffff88802e2aa068 por la tarea 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 Asignado por la tarea 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 Liberado por la tarea 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\nMueve la lectura de le -> link dentro de tipc_node_write_lock(), para que se serialice contra el kfree() en la ruta de eliminaci\u00f3n. Una eliminaci\u00f3n concurrente ahora o no se ha ejecutado todav\u00eda, y vemos un enlace v\u00e1lido, o ya se ha ejecutado, y vemos NULL."}], "id": "CVE-2026-74609", "lastModified": "2026-10-16T20:17:46.070", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "LOW", "attackVector": "LOCAL", "availabilityImpact": "HIGH", "baseScore": 7.8, "baseSeverity": "HIGH", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "privilegesRequired": "LOW", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H", "version": "3.1"}, "exploitabilityScore": 1.8, "impactScore": 5.9, "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "type": "Secondary"}], "ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2026-74609", "options": [{"exploitation": "none"}, {"automatable": "no"}, {"technicalImpact": "total"}], "role": "CISA Coordinator", "timestamp": "2026-10-16T19:02:14.527164Z", "version": "2.0.3"}}]}, "published": "2026-08-22T16:16:33.407", "references": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/2be741ad565c610871a6a95062c12c39da7168fd"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/47ba70891b10b2feb52462086b7fcd2ad75d3ce3"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/5558a8312452ddb21eff22b1cbd84302ad951944"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/69d209461c110388710e483a130caf051e4fd09a"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/a714d62513befef37f71f4ae89bb1fe173b65f2e"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/c3f2347a47754eac690967cfd82cb6d559817b07"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/cba9ccb47e9fa4cc77692fb896cc5ab57a667882"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/de017c22135f545ca4e65d1eada22887b64958eb"}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "vulnStatus": "Received"}

{"bugzilla": {"description": "kernel: tipc: read le->link under the node lock in tipc_node_link_down()", "id": "2521427", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2521427"}, "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-825", "details": ["In the Linux kernel, the following vulnerability has been resolved:\ntipc: read le->link under the node lock in tipc_node_link_down()\ntipc_node_link_down() caches the link pointer before taking n->lock:\nstruct tipc_link *l = le->link;/* unlocked */\nif (!l)\nreturn;\ntipc_node_write_lock(n);\nif (!tipc_link_is_establishing(l)) {/* deref l */\n...\ntipc_link_reset(l);/* write into l */\nif (delete) {\nkfree(l);\nle->link = NULL;\nThe delete=true caller frees that very object under n->lock, so the lock\ndoes not protect the cached pointer against it:\n- CPU A, delete=false: tipc_rcv() on TIPC_LINK_DOWN_EVT, or the link\nsupervision timer via tipc_node_timeout(), reads l unlocked and then\ndereferences 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).\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.\nThe following trace was captured on 7.2.0-rc5-00284-gaf39eb111ce6:\nBUG: KASAN: slab-use-after-free in tipc_link_is_establishing (net/tipc/link.c:285)\nRead of size 4 at addr ffff88802e2aa068 by task swapper/2/0\ntipc_link_is_establishing (net/tipc/link.c:285)\ntipc_node_link_down (net/tipc/node.c:1076)\ntipc_node_timeout (net/tipc/node.c:843)\nAllocated by task 9549:\ntipc_link_create (net/tipc/link.c:490)\ntipc_node_check_dest (net/tipc/node.c:1279)\ntipc_disc_rcv (net/tipc/discover.c:252)\ntipc_udp_recv (net/tipc/udp_media.c:389)\nFreed by task 9549:\ntipc_node_link_down (net/tipc/node.c:1084)\ntipc_node_delete_links (net/tipc/node.c:1320)\nbearer_disable (net/tipc/bearer.c:414)\n__tipc_nl_bearer_disable (net/tipc/bearer.c:992)\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.", "A flaw was found in the Linux kernel's TIPC (Transparent Inter-Process Communication) protocol implementation. A race condition exists in the `tipc_node_link_down()` function where a link pointer is cached without proper locking. This allows another process to free the link object while the cached pointer is still in use, leading to a use-after-free vulnerability. This memory corruption issue could result in a denial of service or potentially information disclosure."], "name": "CVE-2026-74609", "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-2026-74609\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-74609\nhttps://lore.kernel.org/linux-cve-announce/2026082217-CVE-2026-74609-e7db@gregkh/T"], "threat_severity": "Moderate"}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[73f646cec35477b5099d7e952297cb9e1855be45,2be741ad565c610871a6a95062c12c39da7168fd)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[73f646cec35477b5099d7e952297cb9e1855be45,69d209461c110388710e483a130caf051e4fd09a)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[73f646cec35477b5099d7e952297cb9e1855be45,de017c22135f545ca4e65d1eada22887b64958eb)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[73f646cec35477b5099d7e952297cb9e1855be45,47ba70891b10b2feb52462086b7fcd2ad75d3ce3)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[73f646cec35477b5099d7e952297cb9e1855be45,a714d62513befef37f71f4ae89bb1fe173b65f2e)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[73f646cec35477b5099d7e952297cb9e1855be45,c3f2347a47754eac690967cfd82cb6d559817b07)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[73f646cec35477b5099d7e952297cb9e1855be45,5558a8312452ddb21eff22b1cbd84302ad951944)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[73f646cec35477b5099d7e952297cb9e1855be45,cba9ccb47e9fa4cc77692fb896cc5ab57a667882)"}}], "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": "4.4"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "generic", "value": "[0,4.4)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[5.10.265,5.11.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[5.15.216,5.16.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[6.1.183,6.2.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[6.6.152,6.7.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[6.12.104,6.13.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[6.18.45,6.19.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[7.1.9,7.2.0)"}}, {"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": "2026-08-22T17:00:10.932410+00:00", "updated": "2026-08-25T16:00:15.264627+00:00", "vendors": ["linux", "linux$PRODUCT$linux_kernel"]}