{"id":"CVE-2026-98531","revision":"4c294309ae1a485db70b8db2b26936fd","records":[{"revision":"4c294309ae1a485db70b8db2b26936fd","observedAt":"2026-10-23T15:48:27.903+00:00","statement":{"source":"cve-program","id":"CVE-2026-98531","aliases":[],"title":"ipv6: sr: enforce exact attribute length for SEG6_ATTR_DST","description":"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.","state":0,"publishedAt":"2026-10-18T15:17:49.632+00:00","modifiedAt":"2026-10-19T09:21:14.351+00:00","affected":[{"ecosystem":"Vendor product","name":"Linux","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"product\": \"Linux\",\n                    \"vendor\": \"Linux\",\n                    \"defaultStatus\": \"unaffected\",\n                    \"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\n                    \"programFiles\": [\n                        \"net/ipv6/seg6.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"915d7e5e5930b4f01d0971d93b9b25ed17d221aa\",\n                            \"lessThan\": \"050a0aa3c80907b8c60a396b7e04d48d8b1a9e70\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"915d7e5e5930b4f01d0971d93b9b25ed17d221aa\",\n                            \"lessThan\": \"209eefebee54c4a5f01d68b61e8ac9881eca2de9\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"915d7e5e5930b4f01d0971d93b9b25ed17d221aa\",\n                            \"lessThan\": \"e3ac68c1cdc2535d127b2bfd50c263d16c8e4199\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"915d7e5e5930b4f01d0971d93b9b25ed17d221aa\",\n                            \"lessThan\": \"66bf65fa109326e4c4ddeb0b94093379f72838fd\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"915d7e5e5930b4f01d0971d93b9b25ed17d221aa\",\n                            \"lessThan\": \"195813bb7324c338eaba0aaa02b18681ee65b670\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"915d7e5e5930b4f01d0971d93b9b25ed17d221aa\",\n                            \"lessThan\": \"6fcfc362344edea745a69f3a705de50b731f3418\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"915d7e5e5930b4f01d0971d93b9b25ed17d221aa\",\n                            \"lessThan\": \"94214cf0a08dd2c5f37aeeea46078d9dfe8e4a0e\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"915d7e5e5930b4f01d0971d93b9b25ed17d221aa\",\n                            \"lessThan\": \"2d959c75c27f90e9ec489d18ce5ee6b852ad4741\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        }\n                    ]\n                }"},{"ecosystem":"Vendor product","name":"Linux","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"product\": \"Linux\",\n                    \"vendor\": \"Linux\",\n                    \"defaultStatus\": \"affected\",\n                    \"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\n                    \"programFiles\": [\n                        \"net/ipv6/seg6.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"4.10\",\n                            \"status\": \"affected\"\n                        },\n                        {\n                            \"version\": \"0\",\n                            \"lessThan\": \"4.10\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"5.10.271\",\n                            \"lessThanOrEqual\": \"5.10.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"5.15.222\",\n                            \"lessThanOrEqual\": \"5.15.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.1.189\",\n                            \"lessThanOrEqual\": \"6.1.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.6.158\",\n                            \"lessThanOrEqual\": \"6.6.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.12.112\",\n                            \"lessThanOrEqual\": \"6.12.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.18.55\",\n                            \"lessThanOrEqual\": \"6.18.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"7.2.9\",\n                            \"lessThanOrEqual\": \"7.2.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"7.3\",\n                            \"lessThanOrEqual\": \"*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"original_commit_for_fix\"\n                        }\n                    ]\n                }"}],"metrics":[],"references":["https://git.kernel.org/stable/c/050a0aa3c80907b8c60a396b7e04d48d8b1a9e70","https://git.kernel.org/stable/c/209eefebee54c4a5f01d68b61e8ac9881eca2de9","https://git.kernel.org/stable/c/e3ac68c1cdc2535d127b2bfd50c263d16c8e4199","https://git.kernel.org/stable/c/66bf65fa109326e4c4ddeb0b94093379f72838fd","https://git.kernel.org/stable/c/195813bb7324c338eaba0aaa02b18681ee65b670","https://git.kernel.org/stable/c/6fcfc362344edea745a69f3a705de50b731f3418","https://git.kernel.org/stable/c/94214cf0a08dd2c5f37aeeea46078d9dfe8e4a0e","https://git.kernel.org/stable/c/2d959c75c27f90e9ec489d18ce5ee6b852ad4741"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-98531","license":"CVE Program Terms of Use","key":"cve-program:CVE-2026-98531","identifiers":["CVE-2026-98531"]},"retained":false,"historicalAffected":[]}],"coverage":[]}