{"id":"CVE-2026-74667","revision":"c50dc4c988754b94aeb4afe474ebf788","records":[{"revision":"c50dc4c988754b94aeb4afe474ebf788","observedAt":"2026-10-23T15:48:27.903+00:00","statement":{"source":"cve-program","id":"CVE-2026-74667","aliases":[],"title":"net/packet: reset the MAC header on the packet-socket transmit path","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet/packet: reset the MAC header on the packet-socket transmit path\n\npacket_parse_headers() resets the MAC header only for a SOCK_RAW frame\nwhose socket did not bind a protocol. A protocol-bound SOCK_RAW socket,\nany SOCK_DGRAM frame, and the legacy SOCK_PACKET path therefore leave\nskb->mac_header unset here.\n\nFor frames sent via __dev_queue_xmit() this is harmless: it resets the\nMAC header unconditionally. But the packet-socket PACKET_QDISC_BYPASS\npath uses dev_direct_xmit(), which does not, so the frame reaches\nndo_start_xmit() with the MAC header unset. A driver that reads\neth_hdr(skb) on transmit then dereferences skb->head + (u16)~0, an\nout-of-bounds access ~64 KiB past the head -- the same class fixed for\none consumer in commit f5089008f90c (\"macsec: do not read an unset MAC\nheader in macsec_encrypt()\").\n\npacket_parse_headers() runs only on the transmit path, where skb->data\npoints at the start of the L2 header for every packet-socket type\nregardless of its length: SOCK_RAW and SOCK_PACKET carry a user-supplied\nheader and SOCK_DGRAM has one built by dev_hard_header(). Reset the MAC\nheader unconditionally, mirroring __dev_queue_xmit(), so the frame is\nanchored on the bypass path too.\n\nFound by 0sec (https://0sec.ai) using automated source analysis;\nverified against source and matched to the macsec KASAN report in\nf5089008f90c. Compile-tested.","state":0,"publishedAt":"2026-08-22T15:32:38.862+00:00","modifiedAt":"2026-10-16T19:16:08.261+00:00","affected":[{"ecosystem":"Vendor product","name":"Linux","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"product\": \"Linux\",\n                    \"vendor\": \"Linux\",\n                    \"defaultStatus\": \"unaffected\",\n                    \"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\n                    \"programFiles\": [\n                        \"net/packet/af_packet.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"75c65772c3d18447d62d3aca5f91b06c16cc25e4\",\n                            \"lessThan\": \"1e43a1d66615f411d427f9df1f46dd049d9e3681\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"75c65772c3d18447d62d3aca5f91b06c16cc25e4\",\n                            \"lessThan\": \"4057853a91fb796c4f47c7d1baf1aa085394148e\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"75c65772c3d18447d62d3aca5f91b06c16cc25e4\",\n                            \"lessThan\": \"2610ed4e86a4590234a9d70518c469751c5af231\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"75c65772c3d18447d62d3aca5f91b06c16cc25e4\",\n                            \"lessThan\": \"b47ba8fe6e1d2df8c92048de5afafd059447dc30\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"75c65772c3d18447d62d3aca5f91b06c16cc25e4\",\n                            \"lessThan\": \"284f3e7a3f1a743fdf89e304fd1f19d5ffcff46d\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"75c65772c3d18447d62d3aca5f91b06c16cc25e4\",\n                            \"lessThan\": \"971aa7d99242bbf09513e27b7a243f0b29ff23ae\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"75c65772c3d18447d62d3aca5f91b06c16cc25e4\",\n                            \"lessThan\": \"fdd4d7d52358a58e351dd9d82530c04eba8ccd7a\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"75c65772c3d18447d62d3aca5f91b06c16cc25e4\",\n                            \"lessThan\": \"c2707480cfbf19c7619acc9c089d17f20869821f\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        }\n                    ]\n                }"},{"ecosystem":"Vendor product","name":"Linux","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"product\": \"Linux\",\n                    \"vendor\": \"Linux\",\n                    \"defaultStatus\": \"affected\",\n                    \"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\n                    \"programFiles\": [\n                        \"net/packet/af_packet.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"5.1\",\n                            \"status\": \"affected\"\n                        },\n                        {\n                            \"version\": \"0\",\n                            \"lessThan\": \"5.1\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"5.10.265\",\n                            \"lessThanOrEqual\": \"5.10.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"5.15.216\",\n                            \"lessThanOrEqual\": \"5.15.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.1.183\",\n                            \"lessThanOrEqual\": \"6.1.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.6.152\",\n                            \"lessThanOrEqual\": \"6.6.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.12.104\",\n                            \"lessThanOrEqual\": \"6.12.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.18.45\",\n                            \"lessThanOrEqual\": \"6.18.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"7.1.9\",\n                            \"lessThanOrEqual\": \"7.1.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"7.2\",\n                            \"lessThanOrEqual\": \"*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"original_commit_for_fix\"\n                        }\n                    ]\n                }"}],"metrics":[{"system":"CVSS 3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","score":7.8,"severity":"HIGH"}],"references":["https://git.kernel.org/stable/c/1e43a1d66615f411d427f9df1f46dd049d9e3681","https://git.kernel.org/stable/c/4057853a91fb796c4f47c7d1baf1aa085394148e","https://git.kernel.org/stable/c/2610ed4e86a4590234a9d70518c469751c5af231","https://git.kernel.org/stable/c/b47ba8fe6e1d2df8c92048de5afafd059447dc30","https://git.kernel.org/stable/c/284f3e7a3f1a743fdf89e304fd1f19d5ffcff46d","https://git.kernel.org/stable/c/971aa7d99242bbf09513e27b7a243f0b29ff23ae","https://git.kernel.org/stable/c/fdd4d7d52358a58e351dd9d82530c04eba8ccd7a","https://git.kernel.org/stable/c/c2707480cfbf19c7619acc9c089d17f20869821f"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-74667","license":"CVE Program Terms of Use","key":"cve-program:CVE-2026-74667","identifiers":["CVE-2026-74667"]},"retained":false,"historicalAffected":[]}],"coverage":[]}