{"schema":"threatline.record/2","record":{"id":"CVE-2026-98531","aliases":[],"summary":"ipv6: sr: enforce exact attribute length for SEG6_ATTR_DST","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nipv6: sr: enforce exact attribute length for SEG6_ATTR_DST\n\nIn seg6_genl_policy, SEG6_ATTR_DST is defined with .type = NLA_BINARY and\n.len = sizeof(struct in6_addr). For NLA_BINARY, .len only enforces the\nmaximum payload length and permits shorter payloads (e.g., 0 bytes).\nWhen seg6_genl_set_tunsrc() copies sizeof(struct in6_addr) bytes via\nkmemdup(val, sizeof(*val), GFP_KERNEL), a short SEG6_ATTR_DST attribute\ntriggers a 16-byte out-of-bounds read past skb->tail into uninitialized\nskb->head memory, which is stored in sdata->tun_src and leaked back to\nuserspace via SEG6_CMD_GET_TUNSRC.\n\nSwitch SEG6_ATTR_DST in seg6_genl_policy to\nNLA_POLICY_EXACT_LEN(sizeof(struct in6_addr)) so that generic netlink\nvalidation rejects any attribute whose length is not exactly\nsizeof(struct in6_addr) with -ERANGE.\n\nTested in QEMU against Linux 7.3.0-rc3 by sending a SEG6_CMD_SET_TUNSRC\nGeneric Netlink message with a 0-byte SEG6_ATTR_DST attribute followed\nby SEG6_CMD_GET_TUNSRC. On the unfixed kernel, SEG6_CMD_SET_TUNSRC\nsucceeds (err = 0) and SEG6_CMD_GET_TUNSRC leaks 16 bytes of\nuninitialized kernel heap memory (tun_src =\n836a61ecc4d25a1042a8d60411cfb378); with this patch applied,\nSEG6_CMD_SET_TUNSRC is rejected by netlink policy validation with\n-ERANGE (-34) and tun_src remains zeroed.","categories":["Operating systems"],"product":"Linux","vendor":"Linux","ecosystem":null,"affected_ranges":[{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-98531","source_modified_at":"2026-10-19T09:21:14.351Z","fetched_at":"2026-10-23T18:45:31.882637Z","product":"Linux","vendor":"Linux","versions":[{"version":"915d7e5e5930b4f01d0971d93b9b25ed17d221aa","lessThan":"050a0aa3c80907b8c60a396b7e04d48d8b1a9e70","status":"affected","versionType":"git"},{"version":"915d7e5e5930b4f01d0971d93b9b25ed17d221aa","lessThan":"209eefebee54c4a5f01d68b61e8ac9881eca2de9","status":"affected","versionType":"git"},{"version":"915d7e5e5930b4f01d0971d93b9b25ed17d221aa","lessThan":"e3ac68c1cdc2535d127b2bfd50c263d16c8e4199","status":"affected","versionType":"git"},{"version":"915d7e5e5930b4f01d0971d93b9b25ed17d221aa","lessThan":"66bf65fa109326e4c4ddeb0b94093379f72838fd","status":"affected","versionType":"git"},{"version":"915d7e5e5930b4f01d0971d93b9b25ed17d221aa","lessThan":"195813bb7324c338eaba0aaa02b18681ee65b670","status":"affected","versionType":"git"},{"version":"915d7e5e5930b4f01d0971d93b9b25ed17d221aa","lessThan":"6fcfc362344edea745a69f3a705de50b731f3418","status":"affected","versionType":"git"},{"version":"915d7e5e5930b4f01d0971d93b9b25ed17d221aa","lessThan":"94214cf0a08dd2c5f37aeeea46078d9dfe8e4a0e","status":"affected","versionType":"git"},{"version":"915d7e5e5930b4f01d0971d93b9b25ed17d221aa","lessThan":"2d959c75c27f90e9ec489d18ce5ee6b852ad4741","status":"affected","versionType":"git"}],"defaultStatus":"unaffected"},{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-98531","source_modified_at":"2026-10-19T09:21:14.351Z","fetched_at":"2026-10-23T18:45:31.882637Z","product":"Linux","vendor":"Linux","versions":[{"version":"4.10","status":"affected"},{"version":"0","lessThan":"4.10","status":"unaffected","versionType":"semver"},{"version":"5.10.271","lessThanOrEqual":"5.10.*","status":"unaffected","versionType":"semver"},{"version":"5.15.222","lessThanOrEqual":"5.15.*","status":"unaffected","versionType":"semver"},{"version":"6.1.189","lessThanOrEqual":"6.1.*","status":"unaffected","versionType":"semver"},{"version":"6.6.158","lessThanOrEqual":"6.6.*","status":"unaffected","versionType":"semver"},{"version":"6.12.112","lessThanOrEqual":"6.12.*","status":"unaffected","versionType":"semver"},{"version":"6.18.55","lessThanOrEqual":"6.18.*","status":"unaffected","versionType":"semver"},{"version":"7.2.9","lessThanOrEqual":"7.2.*","status":"unaffected","versionType":"semver"},{"version":"7.3","lessThanOrEqual":"*","status":"unaffected","versionType":"original_commit_for_fix"}],"defaultStatus":"affected"}],"fixed_versions":[{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-98531","source_modified_at":"2026-10-19T09:21:14.351Z","fetched_at":"2026-10-23T18:45:31.882637Z","package":{"name":"Linux","ecosystem":null},"version":"050a0aa3c80907b8c60a396b7e04d48d8b1a9e70","basis":"first unaffected version stated in the CVE record"},{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-98531","source_modified_at":"2026-10-19T09:21:14.351Z","fetched_at":"2026-10-23T18:45:31.882637Z","package":{"name":"Linux","ecosystem":null},"version":"209eefebee54c4a5f01d68b61e8ac9881eca2de9","basis":"first unaffected version stated in the CVE record"},{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-98531","source_modified_at":"2026-10-19T09:21:14.351Z","fetched_at":"2026-10-23T18:45:31.882637Z","package":{"name":"Linux","ecosystem":null},"version":"66bf65fa109326e4c4ddeb0b94093379f72838fd","basis":"first unaffected version stated in the CVE record"},{"source":"CVE 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List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-98531","source_modified_at":"2026-10-19T09:21:14.351Z","fetched_at":"2026-10-23T18:45:31.882637Z","package":{"name":"Linux","ecosystem":null},"version":"2d959c75c27f90e9ec489d18ce5ee6b852ad4741","basis":"first unaffected version stated in the CVE record"}],"cvss":null,"severity":null,"kev":{"listed":false},"epss":{"probability":0.0022,"percentile":0.11804,"score_date":"2026-10-23"},"published_at":"2026-10-18T15:17:49.632Z","modified_at":"2026-10-19T09:21:14.351Z","provenance":[{"source":"CVE List","url":"https://www.cve.org/CVERecord?id=CVE-2026-98531","fetched_at":"2026-10-23T18:45:31.882637Z","source_modified_at":"2026-10-19T09:21:14.351Z"},{"source":"EPSS","url":"https://api.first.org/data/v1/epss?cve=CVE-2026-98531","fetched_at":"2026-10-23T18:42:43.628194Z","source_modified_at":"2026-10-23"}],"sources":["CVE List","EPSS"],"references":[{"source":"CVE List","url":"https://git.kernel.org/stable/c/050a0aa3c80907b8c60a396b7e04d48d8b1a9e70"},{"source":"CVE List","url":"https://git.kernel.org/stable/c/209eefebee54c4a5f01d68b61e8ac9881eca2de9"},{"source":"CVE List","url":"https://git.kernel.org/stable/c/e3ac68c1cdc2535d127b2bfd50c263d16c8e4199"},{"source":"CVE List","url":"https://git.kernel.org/stable/c/66bf65fa109326e4c4ddeb0b94093379f72838fd"},{"source":"CVE List","url":"https://git.kernel.org/stable/c/195813bb7324c338eaba0aaa02b18681ee65b670"},{"source":"CVE List","url":"https://git.kernel.org/stable/c/6fcfc362344edea745a69f3a705de50b731f3418"},{"source":"CVE List","url":"https://git.kernel.org/stable/c/94214cf0a08dd2c5f37aeeea46078d9dfe8e4a0e"},{"source":"CVE List","url":"https://git.kernel.org/stable/c/2d959c75c27f90e9ec489d18ce5ee6b852ad4741"}],"locations":[],"motoko_assessment":{"status":"requires_architecture_review","automatic_remediation":false},"cve_state":"PUBLISHED","classification":{"method":"product-first software-layer rules","rules_version":"2.1","matched_on":"product","confidence":"heuristic","reviewed":false},"change_timestamp":"2026-10-19T09:21:14.351Z","content_hash":"5398347202acca4b2083fe6a52022a10b46bb696559a739588d832221a321b7a"}}