{"id":"CVE-2026-99066","state":"PUBLISHED","title":"can: dev: init_can_skb(): restore skb header initialization","description":"In the Linux kernel, the following vulnerability has been resolved:\n\ncan: dev: init_can_skb(): restore skb header initialization\n\nCommit 9f10374bb024 (\"can: remove private CAN skb headroom infrastructure\")\nremoved the skb_reset_mac_header()/skb_reset_network_header()/\nskb_reset_transport_header() calls from init_can_skb(). As a result, RX\nskbs from alloc_can_skb() and friends again carry mac_header = 0xFFFF.\nWhen such an skb reaches packet_rcv_spkt() (SOCK_PACKET), the push length\ncalculation overflows and triggers skb_under_panic -> kernel BUG -> full\nmachine panic.\n\nThe same issue was originally reported in 2014 on linux-can and fixed by\ncommit 969439016d2c (\"can: add missing initialisations in CAN related\nskbuffs\"). packet_rcv_spkt() itself has never been hardened: only\npacket_rcv() and tpacket_rcv() gained dev_has_header() checks in\ncommit d549699048b4 (\"net/packet: fix packet receive on L3 devices\nwithout visible hard header\").","publishedAt":"2026-10-23T12:23:09.516Z","updatedAt":"2026-10-23T12:23:09.516Z","severity":null,"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"9f10374bb024593a611e6845847f0444841a231b","status":"affected","lessThan":"8078375dfd0baecd9f1b7b06bb2d6f88d7cb8632","versionType":"git"},{"version":"9f10374bb024593a611e6845847f0444841a231b","status":"affected","lessThan":"0a04c0cb8606ff88399489d03ef255afe90d0d5f","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/net/can/dev/skb.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"7.0","status":"affected"},{"version":"0","status":"unaffected","lessThan":"7.0","versionType":"semver"},{"version":"7.2.11","status":"unaffected","lessThanOrEqual":"7.2.*","versionType":"semver"},{"version":"7.3","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/net/can/dev/skb.c"]}],"references":["https://git.kernel.org/stable/c/8078375dfd0baecd9f1b7b06bb2d6f88d7cb8632","https://git.kernel.org/stable/c/0a04c0cb8606ff88399489d03ef255afe90d0d5f"],"weaknesses":[],"ingestedAt":"2026-10-29T20:13:43.249Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/99xxx/CVE-2026-99066.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-99066","state":"PUBLISHED","datePublished":"2026-10-23T12:23:09.516Z","dateUpdated":"2026-10-23T12:23:09.516Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-09-25T10:25:14.389Z"},"containers":{"cna":{"title":"can: dev: init_can_skb(): restore skb header initialization","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\ncan: dev: init_can_skb(): restore skb header initialization\n\nCommit 9f10374bb024 (\"can: remove private CAN skb headroom infrastructure\")\nremoved the skb_reset_mac_header()/skb_reset_network_header()/\nskb_reset_transport_header() calls from init_can_skb(). As a result, RX\nskbs from alloc_can_skb() and friends again carry mac_header = 0xFFFF.\nWhen such an skb reaches packet_rcv_spkt() (SOCK_PACKET), the push length\ncalculation overflows and triggers skb_under_panic -> kernel BUG -> full\nmachine panic.\n\nThe same issue was originally reported in 2014 on linux-can and fixed by\ncommit 969439016d2c (\"can: add missing initialisations in CAN related\nskbuffs\"). packet_rcv_spkt() itself has never been hardened: only\npacket_rcv() and tpacket_rcv() gained dev_has_header() checks in\ncommit d549699048b4 (\"net/packet: fix packet receive on L3 devices\nwithout visible hard header\")."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"9f10374bb024593a611e6845847f0444841a231b","status":"affected","lessThan":"8078375dfd0baecd9f1b7b06bb2d6f88d7cb8632","versionType":"git"},{"version":"9f10374bb024593a611e6845847f0444841a231b","status":"affected","lessThan":"0a04c0cb8606ff88399489d03ef255afe90d0d5f","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/net/can/dev/skb.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"7.0","status":"affected"},{"version":"0","status":"unaffected","lessThan":"7.0","versionType":"semver"},{"version":"7.2.11","status":"unaffected","lessThanOrEqual":"7.2.*","versionType":"semver"},{"version":"7.3","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/net/can/dev/skb.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/8078375dfd0baecd9f1b7b06bb2d6f88d7cb8632"},{"url":"https://git.kernel.org/stable/c/0a04c0cb8606ff88399489d03ef255afe90d0d5f"}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-10-23T12:23:09.516Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"7.0","versionEndExcluding":"7.2.11"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"7.0","versionEndExcluding":"7.3"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}}}}}