{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2024-35839","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","state":"PUBLISHED","assignerShortName":"Linux","dateReserved":"2024-05-17T13:50:33.104Z","datePublished":"2024-05-17T14:27:30.524Z","dateUpdated":"2026-08-05T11:30:14.444Z"},"containers":{"cna":{"providerMetadata":{"orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux","dateUpdated":"2026-08-05T11:30:14.444Z"},"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nnetfilter: bridge: replace physindev with physinif in nf_bridge_info\n\nAn skb can be added to a neigh->arp_queue while waiting for an arp\nreply. Where original skb's skb->dev can be different to neigh's\nneigh->dev. For instance in case of bridging dnated skb from one veth to\nanother, the skb would be added to a neigh->arp_queue of the bridge.\n\nAs skb->dev can be reset back to nf_bridge->physindev and used, and as\nthere is no explicit mechanism that prevents this physindev from been\nfreed under us (for instance neigh_flush_dev doesn't cleanup skbs from\ndifferent device's neigh queue) we can crash on e.g. this stack:\n\narp_process\n  neigh_update\n    skb = __skb_dequeue(&neigh->arp_queue)\n      neigh_resolve_output(..., skb)\n        ...\n          br_nf_dev_xmit\n            br_nf_pre_routing_finish_bridge_slow\n              skb->dev = nf_bridge->physindev\n              br_handle_frame_finish\n\nLet's use plain ifindex instead of net_device link. To peek into the\noriginal net_device we will use dev_get_by_index_rcu(). Thus either we\nget device and are safe to use it or we don't get it and drop skb."}],"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 full trigger chain requires local control of netdev lifecycle (creating a bridge/veth topology, installing a DNAT rule, and deleting the ingress port) in addition to injecting the packet, all done through netlink/sysctl in the attacker's own network namespace. Consistent with netfilter/bridge configuration paths being locally reachable.\nAC:L - The attacker deterministically controls every step and their ordering — DNAT to an address with no neighbour entry, veth deletion, then the ARP reply that dequeues the skb — and can stretch the arp_queue residency window arbitrarily via the per-netns neigh sysctls (retrans_time_ms/mcast_solicit), giving ample time to reclaim the freed net_device.\nPR:L - An unprivileged user gets CAP_NET_ADMIN in a new netns via `unshare -Urn`, and br_netfilter_sysctl_default() enables bridge-nf-call-iptables/ip6tables by default in every new netns, so no real privilege is needed to arm and reach the path.\nUI:N - The attacker performs the entire sequence — topology setup, packet injection, device teardown, ARP reply — with no victim action required.\nS:U - The use-after-free corrupts kernel memory within the same security authority; there is no VM, IOMMU, or hypervisor boundary crossed.\nC:H - Use-after-free on a struct net_device whose fields are re-read after free (dev->nd_net, dev->rx_handler_data), giving a reclaim-controlled pointer that is dereferenced — an arbitrary kernel read primitive once the allocation is sprayed.\nI:H - The freed device's rx_handler_data is type-confused into a struct net_bridge_port and written through (br_fdb_update), and the attacker-controlled struct net * from dev_net() feeds NF_HOOK's function-pointer dispatch, enabling arbitrary write and control-flow hijack.\nA:H - Dereferencing the freed net_device reliably oopses/panics the kernel, as observed in the reported production crash stack, and can be triggered repeatedly."}]}],"affected":[{"product":"Linux","vendor":"Linux","defaultStatus":"unaffected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["include/linux/netfilter_bridge.h","include/linux/skbuff.h","net/bridge/br_netfilter_hooks.c","net/bridge/br_netfilter_ipv6.c","net/ipv4/netfilter/nf_reject_ipv4.c","net/ipv6/netfilter/nf_reject_ipv6.c"],"versions":[{"version":"c4e70a87d975d1f561a00abfe2d3cefa2a486c95","lessThan":"7ae19ee81ca56b13c50a78de6c47d5b8fdc9d97b","status":"affected","versionType":"git"},{"version":"c4e70a87d975d1f561a00abfe2d3cefa2a486c95","lessThan":"9325e3188a9cf3f69fc6f32af59844bbc5b90547","status":"affected","versionType":"git"},{"version":"c4e70a87d975d1f561a00abfe2d3cefa2a486c95","lessThan":"544add1f1cfb78c3dfa3e6edcf4668f6be5e730c","status":"affected","versionType":"git"},{"version":"c4e70a87d975d1f561a00abfe2d3cefa2a486c95","lessThan":"9874808878d9eed407e3977fd11fee49de1e1d86","status":"affected","versionType":"git"}]},{"product":"Linux","vendor":"Linux","defaultStatus":"affected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["include/linux/netfilter_bridge.h","include/linux/skbuff.h","net/bridge/br_netfilter_hooks.c","net/bridge/br_netfilter_ipv6.c","net/ipv4/netfilter/nf_reject_ipv4.c","net/ipv6/netfilter/nf_reject_ipv6.c"],"versions":[{"version":"4.2","status":"affected"},{"version":"0","lessThan":"4.2","status":"unaffected","versionType":"semver"},{"version":"6.1.75","lessThanOrEqual":"6.1.*","status":"unaffected","versionType":"semver"},{"version":"6.6.14","lessThanOrEqual":"6.6.*","status":"unaffected","versionType":"semver"},{"version":"6.7.2","lessThanOrEqual":"6.7.*","status":"unaffected","versionType":"semver"},{"version":"6.8","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":"4.2","versionEndExcluding":"6.1.75"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.2","versionEndExcluding":"6.6.14"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.2","versionEndExcluding":"6.7.2"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.2","versionEndExcluding":"6.8"}]}]}],"references":[{"url":"https://git.kernel.org/stable/c/7ae19ee81ca56b13c50a78de6c47d5b8fdc9d97b"},{"url":"https://git.kernel.org/stable/c/9325e3188a9cf3f69fc6f32af59844bbc5b90547"},{"url":"https://git.kernel.org/stable/c/544add1f1cfb78c3dfa3e6edcf4668f6be5e730c"},{"url":"https://git.kernel.org/stable/c/9874808878d9eed407e3977fd11fee49de1e1d86"}],"title":"netfilter: bridge: replace physindev with physinif in nf_bridge_info","x_generator":{"engine":"bippy-1.2.0"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"id":"CVE-2024-35839","role":"CISA Coordinator","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"partial"}],"version":"2.0.3","timestamp":"2024-05-23T19:26:55.890240Z"}}}],"providerMetadata":{"orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","shortName":"CISA-ADP","dateUpdated":"2024-06-04T17:33:44.186Z"}},{"providerMetadata":{"orgId":"af854a3a-2127-422b-91ae-364da2661108","shortName":"CVE","dateUpdated":"2024-08-02T03:21:48.411Z"},"title":"CVE Program Container","references":[{"url":"https://git.kernel.org/stable/c/7ae19ee81ca56b13c50a78de6c47d5b8fdc9d97b","tags":["x_transferred"]},{"url":"https://git.kernel.org/stable/c/9325e3188a9cf3f69fc6f32af59844bbc5b90547","tags":["x_transferred"]},{"url":"https://git.kernel.org/stable/c/544add1f1cfb78c3dfa3e6edcf4668f6be5e730c","tags":["x_transferred"]},{"url":"https://git.kernel.org/stable/c/9874808878d9eed407e3977fd11fee49de1e1d86","tags":["x_transferred"]}]}]}}