{"id":"CVE-2026-98950","summary":"flow_dissector: avoid u16 truncation of hlen in bpf_flow_dissect()","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nflow_dissector: avoid u16 truncation of hlen in bpf_flow_dissect()\n\nbpf_flow_dissect() sanitizes the offsets returned by the BPF program\nwith clamp_t(u16, ..., hlen).\n\nIf hlen is bigger than 65535, the upper bound is truncated before\nthe comparison. For instance, with hlen == 65536, both nhoff and\nthoff are forced to zero, even if the program returned sane values.\n\nThis is the same class of bug as the one fixed in commit 99bda1ecbd56\n(\"flow_dissector: avoid u16 truncation of skb-\u003elen when computing\nthoff\"). That fix does not cover the BPF path, because\n__skb_flow_dissect() returns early when a BPF flow dissector\nhandles the packet.\n\nstruct bpf_flow_keys stores nhoff and thoff as u16, so cap hlen\nto U16_MAX before clamping.\n\nFound by sashiko while reviewing the commit above.","modified":"2026-11-01T02:33:13.374709805Z","published":"2026-10-23T12:19:09.890Z","database_specific":{"cna_assigner":"Linux","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/98xxx/CVE-2026-98950.json"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/3fb5ad2951a6df92c98f4f06cd70f20c50a2eb2a"},{"type":"WEB","url":"https://git.kernel.org/stable/c/46d21495f633e38d40857401504ee51c56ffed2a"},{"type":"WEB","url":"https://git.kernel.org/stable/c/61b43a51a55929ec040bee3ea51af2121b956d05"},{"type":"WEB","url":"https://git.kernel.org/stable/c/6267f8304cbd9ec9f3f53bd227a733e07131492e"},{"type":"WEB","url":"https://git.kernel.org/stable/c/99c59062172620a0bac4ae8cf37c83bb78772cdd"},{"type":"WEB","url":"https://git.kernel.org/stable/c/c44c02c930c6583b235a1937c69ff716c4bb4514"},{"type":"WEB","url":"https://git.kernel.org/stable/c/cc18eb0e9941162c03f03f411ed7f6c339d91fa0"},{"type":"WEB","url":"https://git.kernel.org/stable/c/f202578efc738b883cfa04889eb97328914265a7"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/98xxx/CVE-2026-98950.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-98950"},{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"d58e468b1112dcd1d5193c0a89ff9f98b5a3e8b9"},{"fixed":"46d21495f633e38d40857401504ee51c56ffed2a"},{"fixed":"6267f8304cbd9ec9f3f53bd227a733e07131492e"},{"fixed":"99c59062172620a0bac4ae8cf37c83bb78772cdd"},{"fixed":"c44c02c930c6583b235a1937c69ff716c4bb4514"},{"fixed":"3fb5ad2951a6df92c98f4f06cd70f20c50a2eb2a"},{"fixed":"cc18eb0e9941162c03f03f411ed7f6c339d91fa0"},{"fixed":"61b43a51a55929ec040bee3ea51af2121b956d05"},{"fixed":"f202578efc738b883cfa04889eb97328914265a7"}]}],"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2026-98950.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"4.20.0"},{"fixed":"5.10.273"}]},{"type":"ECOSYSTEM","events":[{"introduced":"5.11.0"},{"fixed":"5.15.224"}]},{"type":"ECOSYSTEM","events":[{"introduced":"5.16.0"},{"fixed":"6.1.191"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.2.0"},{"fixed":"6.6.160"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.7.0"},{"fixed":"6.12.113"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.13.0"},{"fixed":"6.18.57"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.19.0"},{"fixed":"7.2.11"}]}],"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2026-98950.json"}}],"schema_version":"1.9.2"}