{"id":"CVE-2026-98950","published":"2026-10-23T13:17:16.153","lastModified":"2026-10-23T13:17:16.153","description":"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->len 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.","cvssScore":null,"cvssSeverity":null,"cvssVector":null,"cwes":[],"vendors":[],"products":[],"references":[{"url":"https://git.kernel.org/stable/c/3fb5ad2951a6df92c98f4f06cd70f20c50a2eb2a","tags":[]},{"url":"https://git.kernel.org/stable/c/61b43a51a55929ec040bee3ea51af2121b956d05","tags":[]},{"url":"https://git.kernel.org/stable/c/c44c02c930c6583b235a1937c69ff716c4bb4514","tags":[]},{"url":"https://git.kernel.org/stable/c/cc18eb0e9941162c03f03f411ed7f6c339d91fa0","tags":[]},{"url":"https://git.kernel.org/stable/c/f202578efc738b883cfa04889eb97328914265a7","tags":[]}],"exploitRefs":[],"hasPoc":false,"ai":null}