{"id":"CVE-2026-53096","state":"PUBLISHED","title":"bpf: Use RCU-safe iteration in dev_map_redirect_multi() SKB path","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nbpf: Use RCU-safe iteration in dev_map_redirect_multi() SKB path\n\nThe DEVMAP_HASH branch in dev_map_redirect_multi() uses\nhlist_for_each_entry_safe() to iterate hash buckets, but this function\nruns under RCU protection (called from xdp_do_generic_redirect_map()\nin softirq context). Concurrent writers (__dev_map_hash_update_elem,\ndev_map_hash_delete_elem) modify the list using RCU primitives\n(hlist_add_head_rcu, hlist_del_rcu).\n\nhlist_for_each_entry_safe() performs plain pointer dereferences without\nrcu_dereference(), missing the acquire barrier needed to pair with\nwriters' rcu_assign_pointer(). On weakly-ordered architectures (ARM64,\nPOWER), a reader can observe a partially-constructed node. It also\ndefeats CONFIG_PROVE_RCU lockdep validation and KCSAN data-race\ndetection.\n\nReplace with hlist_for_each_entry_rcu() using rcu_read_lock_bh_held()\nas the lockdep condition, consistent with the rcu_dereference_check()\nused in the DEVMAP (non-hash) branch of the same functions. Also fix\nthe same incorrect lockdep_is_held(&dtab->index_lock) condition in\ndev_map_enqueue_multi(), where the lock is not held either.","publishedAt":"2026-06-24T16:30:34.477Z","updatedAt":"2026-10-19T19:57:24.715Z","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":"e624d4ed4aa8cc3c69d1359b0aaea539203ed266","status":"affected","lessThan":"4a3d0fe30b907ff324b1b49756f7e713d67f3645","versionType":"git"},{"version":"e624d4ed4aa8cc3c69d1359b0aaea539203ed266","status":"affected","lessThan":"b089aa6e94d7a08e74d076a0fe274842dc9feccc","versionType":"git"},{"version":"e624d4ed4aa8cc3c69d1359b0aaea539203ed266","status":"affected","lessThan":"571a05ea1baaccc0dc1e0d227b2cbc978b96d392","versionType":"git"},{"version":"e624d4ed4aa8cc3c69d1359b0aaea539203ed266","status":"affected","lessThan":"cb2c1f3cf65b855548e1b8d55a08bfbaa5a0901a","versionType":"git"},{"version":"e624d4ed4aa8cc3c69d1359b0aaea539203ed266","status":"affected","lessThan":"d4c4bd231ebad70e6f30db429e9640bf378b2f52","versionType":"git"},{"version":"e624d4ed4aa8cc3c69d1359b0aaea539203ed266","status":"affected","lessThan":"7027e705062482a8cea43a1c13ede3c35653966f","versionType":"git"},{"version":"e624d4ed4aa8cc3c69d1359b0aaea539203ed266","status":"affected","lessThan":"8ed82f807bb09d2c8455aaa665f2c6cb17bc6a19","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["kernel/bpf/devmap.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"5.14","status":"affected"},{"version":"0","status":"unaffected","lessThan":"5.14","versionType":"semver"},{"version":"5.15.209","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.175","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.141","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.91","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.33","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.0.10","status":"unaffected","lessThanOrEqual":"7.0.*","versionType":"semver"},{"version":"7.1","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["kernel/bpf/devmap.c"]}],"references":["https://git.kernel.org/stable/c/4a3d0fe30b907ff324b1b49756f7e713d67f3645","https://git.kernel.org/stable/c/b089aa6e94d7a08e74d076a0fe274842dc9feccc","https://git.kernel.org/stable/c/571a05ea1baaccc0dc1e0d227b2cbc978b96d392","https://git.kernel.org/stable/c/cb2c1f3cf65b855548e1b8d55a08bfbaa5a0901a","https://git.kernel.org/stable/c/d4c4bd231ebad70e6f30db429e9640bf378b2f52","https://git.kernel.org/stable/c/7027e705062482a8cea43a1c13ede3c35653966f","https://git.kernel.org/stable/c/8ed82f807bb09d2c8455aaa665f2c6cb17bc6a19"],"weaknesses":["CWE-362"],"ingestedAt":"2026-10-29T20:12:16.098Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/53xxx/CVE-2026-53096.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-53096","state":"PUBLISHED","datePublished":"2026-06-24T16:30:34.477Z","dateUpdated":"2026-10-19T19:57:24.715Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-06-09T07:44:35.384Z"},"containers":{"cna":{"title":"bpf: Use RCU-safe iteration in dev_map_redirect_multi() SKB path","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nbpf: Use RCU-safe iteration in dev_map_redirect_multi() SKB path\n\nThe DEVMAP_HASH branch in dev_map_redirect_multi() uses\nhlist_for_each_entry_safe() to iterate hash buckets, but this function\nruns under RCU protection (called from xdp_do_generic_redirect_map()\nin softirq context). Concurrent writers (__dev_map_hash_update_elem,\ndev_map_hash_delete_elem) modify the list using RCU primitives\n(hlist_add_head_rcu, hlist_del_rcu).\n\nhlist_for_each_entry_safe() performs plain pointer dereferences without\nrcu_dereference(), missing the acquire barrier needed to pair with\nwriters' rcu_assign_pointer(). On weakly-ordered architectures (ARM64,\nPOWER), a reader can observe a partially-constructed node. It also\ndefeats CONFIG_PROVE_RCU lockdep validation and KCSAN data-race\ndetection.\n\nReplace with hlist_for_each_entry_rcu() using rcu_read_lock_bh_held()\nas the lockdep condition, consistent with the rcu_dereference_check()\nused in the DEVMAP (non-hash) branch of the same functions. Also fix\nthe same incorrect lockdep_is_held(&dtab->index_lock) condition in\ndev_map_enqueue_multi(), where the lock is not held either."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"e624d4ed4aa8cc3c69d1359b0aaea539203ed266","status":"affected","lessThan":"4a3d0fe30b907ff324b1b49756f7e713d67f3645","versionType":"git"},{"version":"e624d4ed4aa8cc3c69d1359b0aaea539203ed266","status":"affected","lessThan":"b089aa6e94d7a08e74d076a0fe274842dc9feccc","versionType":"git"},{"version":"e624d4ed4aa8cc3c69d1359b0aaea539203ed266","status":"affected","lessThan":"571a05ea1baaccc0dc1e0d227b2cbc978b96d392","versionType":"git"},{"version":"e624d4ed4aa8cc3c69d1359b0aaea539203ed266","status":"affected","lessThan":"cb2c1f3cf65b855548e1b8d55a08bfbaa5a0901a","versionType":"git"},{"version":"e624d4ed4aa8cc3c69d1359b0aaea539203ed266","status":"affected","lessThan":"d4c4bd231ebad70e6f30db429e9640bf378b2f52","versionType":"git"},{"version":"e624d4ed4aa8cc3c69d1359b0aaea539203ed266","status":"affected","lessThan":"7027e705062482a8cea43a1c13ede3c35653966f","versionType":"git"},{"version":"e624d4ed4aa8cc3c69d1359b0aaea539203ed266","status":"affected","lessThan":"8ed82f807bb09d2c8455aaa665f2c6cb17bc6a19","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["kernel/bpf/devmap.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"5.14","status":"affected"},{"version":"0","status":"unaffected","lessThan":"5.14","versionType":"semver"},{"version":"5.15.209","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.175","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.141","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.91","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.33","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.0.10","status":"unaffected","lessThanOrEqual":"7.0.*","versionType":"semver"},{"version":"7.1","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["kernel/bpf/devmap.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/4a3d0fe30b907ff324b1b49756f7e713d67f3645"},{"url":"https://git.kernel.org/stable/c/b089aa6e94d7a08e74d076a0fe274842dc9feccc"},{"url":"https://git.kernel.org/stable/c/571a05ea1baaccc0dc1e0d227b2cbc978b96d392"},{"url":"https://git.kernel.org/stable/c/cb2c1f3cf65b855548e1b8d55a08bfbaa5a0901a"},{"url":"https://git.kernel.org/stable/c/d4c4bd231ebad70e6f30db429e9640bf378b2f52"},{"url":"https://git.kernel.org/stable/c/7027e705062482a8cea43a1c13ede3c35653966f"},{"url":"https://git.kernel.org/stable/c/8ed82f807bb09d2c8455aaa665f2c6cb17bc6a19"}],"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 vulnerable path requires local BPF/netlink setup of an XDP program using a DEVMAP_HASH broadcast redirect and concurrent map update/delete operations. Network packets can trigger the packet-side reader after setup, but the exploit control path is local.\nAC:L - The attacker can control both sides of the race by driving packets through the attached XDP program while another local thread updates or deletes devmap-hash entries. Weakly ordered architectures such as ARM64/POWER are common reasonable deployments, so this is not a rare external condition.\nPR:L - The path requires BPF/CAP_NET_ADMIN-style privileges to create/update the map and load/attach XDP, but these can be available to a low-privileged local attacker through namespace/delegated BPF-token scenarios. It is not reachable by an unauthenticated remote attacker.\nUI:N - No victim action is needed once the attacker has the local privileges and can run the racing BPF/map operations. Packet delivery and map syscalls are attacker-driven.\nS:U - The impact remains within the kernel and the network namespace/security authority being attacked. This is standard kernel memory-safety exposure, not a VM escape or separate-scope boundary bypass.\nC:H - The unsafe non-RCU traversal can observe partially constructed or inconsistent bpf_dtab_netdev objects and dereference attacker-influenced stale kernel pointers. Given the kernel pointer misuse and heap-shaping potential, high confidentiality impact is defensible.\nI:H - The same stale or partially initialized dev/xdp_prog pointers can be used in redirect and BPF program execution paths, making control-flow or object-confusion style corruption plausible. Under the required overestimate rule, this supports high integrity impact.\nA:H - At minimum, dereferencing inconsistent devmap entries can crash or oops the kernel in the packet redirect path. The race is repeatable by the local attacker, so availability impact is high."}]}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-08-05T12:33:21.982Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.14","versionEndExcluding":"5.15.209"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.14","versionEndExcluding":"6.1.175"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.14","versionEndExcluding":"6.6.141"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.14","versionEndExcluding":"6.12.91"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.14","versionEndExcluding":"6.18.33"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.14","versionEndExcluding":"7.0.10"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.14","versionEndExcluding":"7.1"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"id":"CVE-2026-53096","role":"CISA Coordinator","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"total"}],"version":"2.0.3","timestamp":"2026-10-16T15:25:42.393146Z"}}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-362","lang":"en","type":"CWE","description":"CWE-362 Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')"}]}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-10-19T19:57:24.715Z"}}]}}}