{"id":"CVE-2026-53184","summary":"udp: clear skb-\u003edev before running a sockmap verdict","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nudp: clear skb-\u003edev before running a sockmap verdict\n\nOn the UDP receive path skb-\u003edev is repurposed as dev_scratch (the\ntruesize/state cache set by udp_set_dev_scratch()), through the\nunion { struct net_device *dev; unsigned long dev_scratch; } in sk_buff.\n\nWhen a UDP socket is in a sockmap, sk_data_ready is\nsk_psock_verdict_data_ready(), which calls udp_read_skb() -\u003e recv_actor()\n(sk_psock_verdict_recv) to run the attached SK_SKB verdict program in softirq.\nIf that program calls a socket-lookup helper (bpf_sk_lookup_tcp/udp,\nbpf_skc_lookup_tcp), bpf_skc_lookup() does:\n\n\tif (skb-\u003edev)\n\t\tcaller_net = dev_net(skb-\u003edev);\n\nskb-\u003edev still holds the dev_scratch value (a non-NULL integer), so dev_net()\ndereferences it as a struct net_device * and the kernel takes a general\nprotection fault on a non-canonical address in softirq:\n\n  Oops: general protection fault, probably for non-canonical address 0x1010000800004a0\n  CPU: 1 UID: 0 PID: 1406 Comm: syz.2.19 Not tainted 7.1.0-rc6 #1 PREEMPT(full)\n  RIP: 0010:bpf_skc_lookup net/core/filter.c:7033 [inline]\n  RIP: 0010:bpf_sk_lookup+0x45/0x160 net/core/filter.c:7047\n  Call Trace:\n   \u003cIRQ\u003e\n   bpf_prog_4675cb904b7071f8+0x12e/0x14e\n   bpf_prog_run_pin_on_cpu+0xc6/0x1f0\n   sk_psock_verdict_recv+0x1ba/0x350\n   udp_read_skb+0x31a/0x370\n   sk_psock_verdict_data_ready+0x2e3/0x600\n   __udp_enqueue_schedule_skb+0x4c8/0x650\n   udpv6_queue_rcv_one_skb+0x3ec/0x740\n   udp6_unicast_rcv_skb+0x11d/0x140\n   ip6_protocol_deliver_rcu+0x61e/0x950\n   ip6_input_finish+0xa9/0x150\n   NF_HOOK+0x286/0x2f0\n   ip6_input+0x117/0x220\n   NF_HOOK+0x286/0x2f0\n   __netif_receive_skb+0x85/0x200\n   process_backlog+0x374/0x9a0\n   __napi_poll+0x4f/0x1c0\n   net_rx_action+0x3b0/0x770\n   handle_softirqs+0x15a/0x460\n   do_softirq+0x57/0x80\n   \u003c/IRQ\u003e\n\nThe rmem charge that dev_scratch accounted for is released by skb_recv_udp() on\ndequeue, just above, so the scratch is dead by the time recv_actor() runs. Clear\nskb-\u003edev so bpf_skc_lookup() falls back to sock_net(skb-\u003esk), which\nskb_set_owner_sk_safe() set just above.","modified":"2026-07-08T08:07:23.581315678Z","published":"2026-06-25T08:38:58.189Z","related":["CGA-c3rf-6pxx-5jpq"],"database_specific":{"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/53xxx/CVE-2026-53184.json","cna_assigner":"Linux"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/1b585673a2249f13678e7ac443ac683ba767e0b6"},{"type":"WEB","url":"https://git.kernel.org/stable/c/263779a6beff03b8b06f6d25566cb0f45af361f2"},{"type":"WEB","url":"https://git.kernel.org/stable/c/3c94f241f776562c489876ff506f366224565c21"},{"type":"WEB","url":"https://git.kernel.org/stable/c/6822eed69572000a181fa4e31fceacc60918c471"},{"type":"WEB","url":"https://git.kernel.org/stable/c/7d6d92d000ebe3a845a17c165c1d3a70c5d84fe1"},{"type":"WEB","url":"https://git.kernel.org/stable/c/90d35188aaa92b8f8b23f66335e0e91bf60103a3"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/53xxx/CVE-2026-53184.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-53184"},{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"965b57b469a589d64d81b1688b38dcb537011bb0"},{"fixed":"263779a6beff03b8b06f6d25566cb0f45af361f2"},{"fixed":"1b585673a2249f13678e7ac443ac683ba767e0b6"},{"fixed":"90d35188aaa92b8f8b23f66335e0e91bf60103a3"},{"fixed":"6822eed69572000a181fa4e31fceacc60918c471"},{"fixed":"7d6d92d000ebe3a845a17c165c1d3a70c5d84fe1"},{"fixed":"3c94f241f776562c489876ff506f366224565c21"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-53184.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"6.0.0"},{"fixed":"6.1.176"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.2.0"},{"fixed":"6.6.143"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.7.0"},{"fixed":"6.12.94"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.13.0"},{"fixed":"6.18.36"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.19.0"},{"fixed":"7.0.13"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-53184.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"}]}