{"id":"CVE-2026-74288","state":"PUBLISHED","title":"net: fib_rules: Don't dump dying fib_rule in fib_rules_dump().","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet: fib_rules: Don't dump dying fib_rule in fib_rules_dump().\n\nrocker_router_fib_event() calls fib_rule_get() during RCU dump.\n\nIf the fib_rule is dying, refcount_inc() will complain about it.\n\nLet's call refcount_inc_not_zero() in fib_rules_dump().","publishedAt":"2026-08-15T05:57:55.760Z","updatedAt":"2026-10-16T18:55:30.358Z","severity":{"score":7.8,"label":"High","version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","source":"Linux"},"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"5d7bfd141924a5ece21eb612ad3c56612f041c1e","status":"affected","lessThan":"0f929b59f4cd0e05bb1ecefe12b77e85911d4be2","versionType":"git"},{"version":"5d7bfd141924a5ece21eb612ad3c56612f041c1e","status":"affected","lessThan":"4b7ae30c81c2ee10a644749a3704a5c797ccc308","versionType":"git"},{"version":"5d7bfd141924a5ece21eb612ad3c56612f041c1e","status":"affected","lessThan":"2dfdc210d240bd48bb2ea746430b02b5571b6db9","versionType":"git"},{"version":"5d7bfd141924a5ece21eb612ad3c56612f041c1e","status":"affected","lessThan":"a7ef30753353ba6a95d693b1863a0214222a199a","versionType":"git"},{"version":"5d7bfd141924a5ece21eb612ad3c56612f041c1e","status":"affected","lessThan":"1fbc6c6efe78f4454a51afa0587efb6826f60f00","versionType":"git"},{"version":"5d7bfd141924a5ece21eb612ad3c56612f041c1e","status":"affected","lessThan":"bb4a5b3c91af3c8d705bb2e9f6f8069a70db26fc","versionType":"git"},{"version":"5d7bfd141924a5ece21eb612ad3c56612f041c1e","status":"affected","lessThan":"3af0bc1bd9039e2e50abf3e2d7fee411f38bce4e","versionType":"git"},{"version":"5d7bfd141924a5ece21eb612ad3c56612f041c1e","status":"affected","lessThan":"2821e85c058f81c9948a2fb1a634f7b47457d51c","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["include/net/fib_rules.h","net/core/fib_rules.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"4.12","status":"affected"},{"version":"0","status":"unaffected","lessThan":"4.12","versionType":"semver"},{"version":"5.10.261","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.212","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.178","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.145","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.97","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.40","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.1.5","status":"unaffected","lessThanOrEqual":"7.1.*","versionType":"semver"},{"version":"7.2","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["include/net/fib_rules.h","net/core/fib_rules.c"]}],"references":["https://git.kernel.org/stable/c/0f929b59f4cd0e05bb1ecefe12b77e85911d4be2","https://git.kernel.org/stable/c/4b7ae30c81c2ee10a644749a3704a5c797ccc308","https://git.kernel.org/stable/c/2dfdc210d240bd48bb2ea746430b02b5571b6db9","https://git.kernel.org/stable/c/a7ef30753353ba6a95d693b1863a0214222a199a","https://git.kernel.org/stable/c/1fbc6c6efe78f4454a51afa0587efb6826f60f00","https://git.kernel.org/stable/c/bb4a5b3c91af3c8d705bb2e9f6f8069a70db26fc","https://git.kernel.org/stable/c/3af0bc1bd9039e2e50abf3e2d7fee411f38bce4e","https://git.kernel.org/stable/c/2821e85c058f81c9948a2fb1a634f7b47457d51c"],"weaknesses":[],"ingestedAt":"2026-10-29T20:12:58.252Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/74xxx/CVE-2026-74288.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-74288","state":"PUBLISHED","datePublished":"2026-08-15T05:57:55.760Z","dateUpdated":"2026-10-16T18:55:30.358Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-08-15T05:44:03.881Z"},"containers":{"cna":{"title":"net: fib_rules: Don't dump dying fib_rule in fib_rules_dump().","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet: fib_rules: Don't dump dying fib_rule in fib_rules_dump().\n\nrocker_router_fib_event() calls fib_rule_get() during RCU dump.\n\nIf the fib_rule is dying, refcount_inc() will complain about it.\n\nLet's call refcount_inc_not_zero() in fib_rules_dump()."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"5d7bfd141924a5ece21eb612ad3c56612f041c1e","status":"affected","lessThan":"0f929b59f4cd0e05bb1ecefe12b77e85911d4be2","versionType":"git"},{"version":"5d7bfd141924a5ece21eb612ad3c56612f041c1e","status":"affected","lessThan":"4b7ae30c81c2ee10a644749a3704a5c797ccc308","versionType":"git"},{"version":"5d7bfd141924a5ece21eb612ad3c56612f041c1e","status":"affected","lessThan":"2dfdc210d240bd48bb2ea746430b02b5571b6db9","versionType":"git"},{"version":"5d7bfd141924a5ece21eb612ad3c56612f041c1e","status":"affected","lessThan":"a7ef30753353ba6a95d693b1863a0214222a199a","versionType":"git"},{"version":"5d7bfd141924a5ece21eb612ad3c56612f041c1e","status":"affected","lessThan":"1fbc6c6efe78f4454a51afa0587efb6826f60f00","versionType":"git"},{"version":"5d7bfd141924a5ece21eb612ad3c56612f041c1e","status":"affected","lessThan":"bb4a5b3c91af3c8d705bb2e9f6f8069a70db26fc","versionType":"git"},{"version":"5d7bfd141924a5ece21eb612ad3c56612f041c1e","status":"affected","lessThan":"3af0bc1bd9039e2e50abf3e2d7fee411f38bce4e","versionType":"git"},{"version":"5d7bfd141924a5ece21eb612ad3c56612f041c1e","status":"affected","lessThan":"2821e85c058f81c9948a2fb1a634f7b47457d51c","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["include/net/fib_rules.h","net/core/fib_rules.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"4.12","status":"affected"},{"version":"0","status":"unaffected","lessThan":"4.12","versionType":"semver"},{"version":"5.10.261","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.212","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.178","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.145","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.97","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.40","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.1.5","status":"unaffected","lessThanOrEqual":"7.1.*","versionType":"semver"},{"version":"7.2","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["include/net/fib_rules.h","net/core/fib_rules.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/0f929b59f4cd0e05bb1ecefe12b77e85911d4be2"},{"url":"https://git.kernel.org/stable/c/4b7ae30c81c2ee10a644749a3704a5c797ccc308"},{"url":"https://git.kernel.org/stable/c/2dfdc210d240bd48bb2ea746430b02b5571b6db9"},{"url":"https://git.kernel.org/stable/c/a7ef30753353ba6a95d693b1863a0214222a199a"},{"url":"https://git.kernel.org/stable/c/1fbc6c6efe78f4454a51afa0587efb6826f60f00"},{"url":"https://git.kernel.org/stable/c/bb4a5b3c91af3c8d705bb2e9f6f8069a70db26fc"},{"url":"https://git.kernel.org/stable/c/3af0bc1bd9039e2e50abf3e2d7fee411f38bce4e"},{"url":"https://git.kernel.org/stable/c/2821e85c058f81c9948a2fb1a634f7b47457d51c"}],"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 bug is reached only through local kernel networking control paths: fib_rules_dump() runs during register_fib_notifier() and races with RTM_DELRULE netlink handling in fib_delrule(), not via remotely received packets or a network-facing protocol handler.\nAC:L - Exploitation is a race where the attacker concurrently deletes FIB rules (repeated RTM_DELRULE or netns teardown) while fib_rules_dump() replays RULE_ADD events; the attacker controls both sides and can retry, as demonstrated by syzbot during netdevsim reload/cleanup_net.\nPR:L - Triggering concurrent FIB rule deletion requires CAP_NET_ADMIN on the target network namespace, which unprivileged users can obtain inside user/network namespaces (e.g., unshare -Urn), while driver registration commonly occurs in the same namespace during netdevsim/devlink setup.\nUI:N - No end-user or administrator UI action is required beyond programmatic netlink/devlink operations that an attacker can script; exploitation does not depend on a victim opening files, clicking links, or mounting filesystems.\nS:U - Impact is a kernel heap use-after-free in fib_rule handling leading to memory corruption within the host kernel; it does not inherently cross a VM/hypervisor or IOMMU security boundary without separate exploitation of unrelated boundaries.\nC:H - A dying fib_rule can be passed to FIB notifiers after its refcount hits zero; handlers such as rocker_router_fib_event() call fib_rule_get() and later dereference rule fields in workqueues, enabling reads of freed slab memory and potential kernel pointer disclosure.\nI:H - The UAF hands attackers control over the lifetime and contents of freed fib_rule objects; with heap grooming this class of corruption is reasonably leveraged into arbitrary kernel writes or control-flow hijack, not merely a benign warning.\nA:H - refcount_inc() on a zero refcount emits use-after-free warnings and concurrent dereference of freed fib_rule structures during dump/replay can cause kernel oops/panics, especially under automated stress seen in syzbot reproductions."}]}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-08-17T05:45:27.821Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.12","versionEndExcluding":"5.10.261"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.12","versionEndExcluding":"5.15.212"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.12","versionEndExcluding":"6.1.178"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.12","versionEndExcluding":"6.6.145"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.12","versionEndExcluding":"6.12.97"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.12","versionEndExcluding":"6.18.40"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.12","versionEndExcluding":"7.1.5"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.12","versionEndExcluding":"7.2"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}},"adp":[{"title":"CISA 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