{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-90078", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-09-11T19:38:34.785Z", "datePublished": "2026-09-17T16:05:56.878Z", "dateUpdated": "2026-10-19T08:57:34.924Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-10-19T08:57:34.924Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet/sched: act_skbmod: fix length calculations and avoid invalid header warnings\n\nsyzbot reported a warning in skb_network_header_len() triggered\nby tcf_skbmod_act():\n\n !skb_transport_header_was_set(skb)\n WARNING: CPU: 0 PID: 14949 at include/linux/skbuff.h:3243 skb_network_header_len include/linux/skbuff.h:3243 [inline]\n WARNING: CPU: 0 PID: 14949 at net/sched/act_skbmod.c:55 tcf_skbmod_act+0xfe8/0x1810 net/sched/act_skbmod.c:55\n\nThere are a few issues in tcf_skbmod_act():\n\n1. Calling skb_network_header_len() assumes skb->transport_header is set,\n which is not guaranteed when tcf_skbmod_act() runs at TC ingress.\n2. Unconditionally calling skb_mac_header_len() at the beginning of\n tcf_skbmod_act() triggers a warning on L3 devices (e.g. TUN) where the\n MAC header is unset, evaluating to an underflowed garbage length.\n3. On TC ingress, skb->data points to the network header. Adding the MAC\n header length to the IP header length causes skb_ensure_writable() to\n request more bytes than the actual IP packet length, dropping valid\n short packets (e.g. 28-byte UDP/IPv4 packets).\n\nFix these by:\n- Using skb_network_offset(skb) + sizeof(struct iphdr/ipv6hdr) for\n SKBMOD_F_ECN so that the required length is correctly calculated on\n both ingress (offset == 0) and egress (offset == mac_len).\n- Setting max_edit_len to ETH_HLEN for Ethernet header modifications\n after validating ARPHRD_ETHER." } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "net/sched/act_skbmod.c" ], "versions": [ { "version": "56af5e749f20c3a540310c207dcc373f4f09156e", "lessThan": "985a37781ade19061400100c2ba0f43979dd4d63", "status": "affected", "versionType": "git" }, { "version": "56af5e749f20c3a540310c207dcc373f4f09156e", "lessThan": "d896843d8d925f0adbba319020595cfb1a7bcd57", "status": "affected", "versionType": "git" }, { "version": "56af5e749f20c3a540310c207dcc373f4f09156e", "lessThan": "0675cff3c2924eb9b80d9dd250cf56a1140af157", "status": "affected", "versionType": "git" }, { "version": "56af5e749f20c3a540310c207dcc373f4f09156e", "lessThan": "e8a2027b7e686784a69b2dfcee841d779919f313", "status": "affected", "versionType": "git" }, { "version": "56af5e749f20c3a540310c207dcc373f4f09156e", "lessThan": "1719865b20b22c88d2a55e922eff5ca31b0841f6", "status": "affected", "versionType": "git" }, { "version": "56af5e749f20c3a540310c207dcc373f4f09156e", "lessThan": "62126464f3a6159c0a3dd89e196ba65bfeb0afc6", "status": "affected", "versionType": "git" }, { "version": "56af5e749f20c3a540310c207dcc373f4f09156e", "lessThan": "81d0d1e64f30d9989c829c0953cd6e6c68d9c5fb", "status": "affected", "versionType": "git" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "net/sched/act_skbmod.c" ], "versions": [ { "version": "5.15", "status": "affected" }, { "version": "0", "lessThan": "5.15", "status": "unaffected", "versionType": "semver" }, { "version": "5.15.221", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.188", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.157", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.110", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.52", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.2.6", "lessThanOrEqual": "7.2.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.3", "lessThanOrEqual": "*", "status": "unaffected", "versionType": "original_commit_for_fix" } ] } ], "cpeApplicability": [ { "nodes": [ { "operator": "OR", "negate": false, "cpeMatch": [ { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.15", "versionEndExcluding": "5.15.221" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.15", "versionEndExcluding": "6.1.188" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.15", "versionEndExcluding": "6.6.157" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.15", "versionEndExcluding": "6.12.110" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.15", "versionEndExcluding": "6.18.52" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.15", "versionEndExcluding": "7.2.6" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.15", "versionEndExcluding": "7.3" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/985a37781ade19061400100c2ba0f43979dd4d63" }, { "url": "https://git.kernel.org/stable/c/d896843d8d925f0adbba319020595cfb1a7bcd57" }, { "url": "https://git.kernel.org/stable/c/0675cff3c2924eb9b80d9dd250cf56a1140af157" }, { "url": "https://git.kernel.org/stable/c/e8a2027b7e686784a69b2dfcee841d779919f313" }, { "url": "https://git.kernel.org/stable/c/1719865b20b22c88d2a55e922eff5ca31b0841f6" }, { "url": "https://git.kernel.org/stable/c/62126464f3a6159c0a3dd89e196ba65bfeb0afc6" }, { "url": "https://git.kernel.org/stable/c/81d0d1e64f30d9989c829c0953cd6e6c68d9c5fb" } ], "title": "net/sched: act_skbmod: fix length calculations and avoid invalid header warnings", "x_generator": { "engine": "bippy-1.2.0" } } } }