{"id":"CVE-2026-80738","summary":"bpf: Check sk_state before sk_protocol in bpf_tcp_*_syncookie","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nbpf: Check sk_state before sk_protocol in bpf_tcp_*_syncookie\n\nbpf_tcp_gen_syncookie and bpf_tcp_check_syncookie accept a socket pointer\n'sk' with argument type ARG_PTR_TO_BTF_ID_SOCK_COMMON. However, they access\nsk-\u003esk_protocol without validating whether 'sk' represents a full socket.\n\nFix this issue by checking sk-\u003esk_state != TCP_LISTEN before inspecting\nsk-\u003esk_protocol in both bpf_tcp_gen_syncookie and bpf_tcp_check_syncookie.\nSince mini-sockets are never in the TCP_LISTEN state, the condition\nshort-circuits and prevents dereferencing fullsock-specific fields.","modified":"2026-09-05T03:48:34.713160217Z","published":"2026-09-03T08:21:53.143Z","database_specific":{"cna_assigner":"Linux","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/80xxx/CVE-2026-80738.json"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/23f682083aa3fbc0c49667818efd6979a8bc5ac2"},{"type":"WEB","url":"https://git.kernel.org/stable/c/31a420a822ff92e2090bd5d65efe8e34e2d6d9b8"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/80xxx/CVE-2026-80738.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-80738"},{"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":"399040847084a69f345e0a52fd62f04654e0fce3"},{"fixed":"23f682083aa3fbc0c49667818efd6979a8bc5ac2"},{"fixed":"31a420a822ff92e2090bd5d65efe8e34e2d6d9b8"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-80738.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"5.2.0"},{"fixed":"7.1.9"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-80738.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:L"}]}