{"id":"CVE-2026-80731","revision":"ec8485992a414f5fbc99aca3d2ef71e2","records":[{"revision":"ec8485992a414f5fbc99aca3d2ef71e2","observedAt":"2026-10-23T15:48:27.903+00:00","statement":{"source":"cve-program","id":"CVE-2026-80731","aliases":[],"title":"net: remove CAP_SYS_RAWIO zero-padding in dev_validate_header","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet: remove CAP_SYS_RAWIO zero-padding in dev_validate_header\n\ndev_validate_header() reads dev->hard_header_len directly when\nzero-padding short link layer headers for CAP_SYS_RAWIO holders:\n\n if (capable(CAP_SYS_RAWIO)) {\n memset(ll_header + len, 0, dev->hard_header_len - len);\n return true;\n }\n\nPacket send paths call dev_validate_header() on skbs whose headroom was\nallocated from an earlier hard_header_len read. If the device is\nreconfigured so that dev->hard_header_len increases before validation,\nthe memset writes past the reserved buffer, an out-of-bounds write.\n\nThis out-of-bounds write is masked in some SOCK_RAW paths today because\nthe same concurrent increase can first make skb_push() exceed the\nreserved headroom and trigger skb_under_panic(). Remove the zero-padding\nbranch before making those hard_header_len reads consistent, so the\nsnapshot fixes do not turn a loud panic into a silent overwrite.\n\nThis path is only reached for variable length L2 protocols, where\nlen < hard_header_len but len >= min_header_len. No remaining in-tree\nvariable length L2 protocol implements header_ops->validate, and the\nCAP_SYS_RAWIO bypass that zero-pads and accepts short headers has no\nreal value beyond allowing testing of intentionally malformed input.\n\nDrop the CAP_SYS_RAWIO branch. The remaining reads of\ndev->hard_header_len in dev_validate_header() are comparisons only and\nhave no memory safety impact.","state":0,"publishedAt":"2026-09-03T08:21:48.924+00:00","modifiedAt":"2026-10-16T19:26:36.02+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 \"include/linux/netdevice.h\"\n ],\n \"versions\": [\n {\n \"version\": \"b5518429e70cd783b8ca52335456172c1a0589f6\",\n \"lessThan\": \"53fd7f912c0877647d6a1e1877f5ea8535ee0b4a\",\n \"status\": \"affected\",\n \"versionType\": \"git\"\n },\n {\n \"version\": \"2793a23aacbd754dbbb5cb75093deb7e4103bace\",\n \"lessThan\": \"fa6d98dd925e72fc028b26a0cbbff9d2f0601ff6\",\n \"status\": \"affected\",\n \"versionType\": \"git\"\n },\n {\n \"version\": \"2793a23aacbd754dbbb5cb75093deb7e4103bace\",\n \"lessThan\": \"8fc9816404166a90ed8d544dc52482fafffb6d9f\",\n \"status\": \"affected\",\n \"versionType\": \"git\"\n },\n {\n \"version\": \"2793a23aacbd754dbbb5cb75093deb7e4103bace\",\n \"lessThan\": \"b0f92a5731dc82556a9ae005cc35f71ab136307b\",\n \"status\": \"affected\",\n \"versionType\": \"git\"\n },\n {\n \"version\": \"2793a23aacbd754dbbb5cb75093deb7e4103bace\",\n \"lessThan\": \"99df6b7a713f96eda206680d100b76e15f9d9b69\",\n \"status\": \"affected\",\n \"versionType\": \"git\"\n },\n {\n \"version\": \"2793a23aacbd754dbbb5cb75093deb7e4103bace\",\n \"lessThan\": \"74e035f07f53feca09e2352e77fccb09cad5e208\",\n \"status\": \"affected\",\n \"versionType\": \"git\"\n },\n {\n \"version\": \"2793a23aacbd754dbbb5cb75093deb7e4103bace\",\n \"lessThan\": \"dbb30dc943a93e083f1e531bfdc6779e57de40d0\",\n \"status\": \"affected\",\n \"versionType\": \"git\"\n },\n {\n \"version\": \"2793a23aacbd754dbbb5cb75093deb7e4103bace\",\n \"lessThan\": \"fc902f52a02298c7432b2334c0c82a2885a1a8b6\",\n \"status\": \"affected\",\n \"versionType\": \"git\"\n },\n {\n \"version\": \"2793a23aacbd754dbbb5cb75093deb7e4103bace\",\n \"lessThan\": \"3b9a324e646d3657a8d9806dfbfe4f3e4066e882\",\n \"status\": \"affected\",\n \"versionType\": \"git\"\n },\n {\n \"version\": \"f58a6c08ebdfa978178bbca78c2ba744a2665912\",\n \"status\": \"affected\",\n \"versionType\": \"git\"\n },\n {\n \"version\": \"1df16498dfd0d5a129bdf2982d9a08df73e8923d\",\n \"status\": \"affected\",\n \"versionType\": \"git\"\n },\n {\n \"version\": \"8b8d278aa4de9335682bbd4a3bb619af015c859e\",\n \"status\": \"affected\",\n \"versionType\": \"git\"\n },\n {\n \"version\": \"6804052fa9d86e9a512c88b24a5debbfc1a490fc\",\n \"status\": \"affected\",\n \"versionType\": \"git\"\n },\n {\n \"version\": \"3.2.80\",\n \"lessThan\": \"3.2.81\",\n \"status\": \"affected\",\n \"versionType\": \"semver\"\n },\n {\n \"version\": \"3.16.36\",\n \"lessThan\": \"3.17\",\n \"status\": \"affected\",\n \"versionType\": \"semver\"\n },\n {\n \"version\": \"4.1.28\",\n \"lessThan\": \"4.2\",\n \"status\": \"affected\",\n \"versionType\": \"semver\"\n },\n {\n \"version\": \"4.4.8\",\n \"lessThan\": \"4.5\",\n \"status\": \"affected\",\n \"versionType\": \"semver\"\n },\n {\n \"version\": \"4.5.2\",\n \"lessThan\": \"4.6\",\n \"status\": \"affected\",\n \"versionType\": \"semver\"\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 \"include/linux/netdevice.h\"\n ],\n \"versions\": [\n {\n \"version\": \"4.6\",\n \"status\": \"affected\"\n },\n {\n \"version\": \"0\",\n \"lessThan\": \"4.6\",\n \"status\": \"unaffected\",\n \"versionType\": \"semver\"\n },\n {\n \"version\": \"3.2.81\",\n \"lessThanOrEqual\": \"3.2.*\",\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/53fd7f912c0877647d6a1e1877f5ea8535ee0b4a","https://git.kernel.org/stable/c/fa6d98dd925e72fc028b26a0cbbff9d2f0601ff6","https://git.kernel.org/stable/c/8fc9816404166a90ed8d544dc52482fafffb6d9f","https://git.kernel.org/stable/c/b0f92a5731dc82556a9ae005cc35f71ab136307b","https://git.kernel.org/stable/c/99df6b7a713f96eda206680d100b76e15f9d9b69","https://git.kernel.org/stable/c/74e035f07f53feca09e2352e77fccb09cad5e208","https://git.kernel.org/stable/c/dbb30dc943a93e083f1e531bfdc6779e57de40d0","https://git.kernel.org/stable/c/fc902f52a02298c7432b2334c0c82a2885a1a8b6","https://git.kernel.org/stable/c/3b9a324e646d3657a8d9806dfbfe4f3e4066e882"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-80731","license":"CVE Program Terms of Use","key":"cve-program:CVE-2026-80731","identifiers":["CVE-2026-80731"]},"retained":false,"historicalAffected":[]}],"coverage":[]}