{"id":"CVE-2026-80742","title":"af_packet: Don't send zero-byte data in tpacket_snd().","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\naf_packet: Don't send zero-byte data in tpacket_snd().\n\nsyzbot reported a WARNING in __dev_queue_xmit() triggered via tpacket_snd():\n\nskb_assert_len\nWARNING: at include…","severity":"none","vendor":"Linux","product":"Linux","affected":["Linux >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < dde212f8622f5cb36223fff1ebd6e6f2a3dc61fe","Linux >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < 80a702964467b998d254f16cc61c2c9a20540c9d","Linux >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < 7521e691c7c4f2231634c95053281ac888d1f452","Linux >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < 1fc70b3d513bafb16b17540178870ef46e81c0bb","Linux >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < 3fa110f9e2ea96f567f2194c673c4bc327640111","Linux >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < 98c5914d6b7bd4b4675535908e57dea31f1efd6a","Linux >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < f09ac5682f1bb67981fcb6ead4d3cfe439225876","Linux >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < 6bcd76c134c55c697148acb5c0194e9666abdf84","Linux 2.6.12"],"ssvc":{"exploitation":"none","automatable":"no","technicalImpact":"partial","timestamp":"2026-11-06T17:02:59.452949Z"},"published":"2026-09-03","updated":"2026-11-06","sourceUpdated":"2026-11-06T17:05:53.513Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-80742","references":[{"url":"https://git.kernel.org/stable/c/dde212f8622f5cb36223fff1ebd6e6f2a3dc61fe"},{"url":"https://git.kernel.org/stable/c/80a702964467b998d254f16cc61c2c9a20540c9d"},{"url":"https://git.kernel.org/stable/c/7521e691c7c4f2231634c95053281ac888d1f452"},{"url":"https://git.kernel.org/stable/c/1fc70b3d513bafb16b17540178870ef46e81c0bb"},{"url":"https://git.kernel.org/stable/c/3fa110f9e2ea96f567f2194c673c4bc327640111"},{"url":"https://git.kernel.org/stable/c/98c5914d6b7bd4b4675535908e57dea31f1efd6a"},{"url":"https://git.kernel.org/stable/c/f09ac5682f1bb67981fcb6ead4d3cfe439225876"},{"url":"https://git.kernel.org/stable/c/6bcd76c134c55c697148acb5c0194e9666abdf84"}],"tags":["cve.org"],"epss":0.00177,"epssPercentile":0.0727,"ingestedAt":"2026-11-06T18:00:12.534Z","slug":"CVE-2026-80742","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\naf_packet: Don't send zero-byte data in tpacket_snd().\n\nsyzbot reported a WARNING in __dev_queue_xmit() triggered via tpacket_snd():\n\nskb_assert_len\nWARNING: at include/linux/skbuff.h:2753 skb_assert_len\nWARNING: at __dev_queue_xmit+0x21bc/0x4970 net/core/dev.c:4781\n\nCall Trace:\n <TASK>\n dev_queue_xmit include/linux/netdevice.h:3448 [inline]\n packet_xmit+0x243/0x310 net/packet/af_packet.c:276\n tpacket_snd net/packet/af_packet.c:2907 [inline]\n packet_sendmsg+0x28d6/0x4eb0 net/packet/af_packet.c:3134\n\nWhen sending 0-byte packets via TPACKET ring buffer on devices with no\nhard header (e.g. dev->hard_header_len == 0), tpacket_fill_skb()\npopulates an skb with skb->len == 0 and returns 0. tpacket_snd() then\nforwards this empty skb to packet_xmit(), causing __dev_queue_xmit() to\nhit skb_assert_len(skb).\n\nSimilar checks exist in packet_snd() via commit dc633700f00f\n(\"net/af_packet: check len when min_header_len equals to 0\") and in\npacket_sendmsg_spkt() via commit 6a341729fb31 (\"af_packet: Don't send\nzero-byte data in packet_sendmsg_spkt().\").\n\nReturn -EINVAL in tpacket_fill_skb() when skb->len is zero to reject\nzero-length packets in tpacket_snd().\n\n## Affected\n\n- `Linux >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < dde212f8622f5cb36223fff1ebd6e6f2a3dc61fe`\n- `Linux >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < 80a702964467b998d254f16cc61c2c9a20540c9d`\n- `Linux >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < 7521e691c7c4f2231634c95053281ac888d1f452`\n- `Linux >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < 1fc70b3d513bafb16b17540178870ef46e81c0bb`\n- `Linux >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < 3fa110f9e2ea96f567f2194c673c4bc327640111`\n- `Linux >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < 98c5914d6b7bd4b4675535908e57dea31f1efd6a`\n- `Linux >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < f09ac5682f1bb67981fcb6ead4d3cfe439225876`\n- `Linux >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < 6bcd76c134c55c697148acb5c0194e9666abdf84`\n- `Linux 2.6.12`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"sunlit","depthScore":3,"depthScoreParts":{"impact":2.8,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}