{"schema":"threatline.record/2","record":{"id":"CVE-2026-98647","aliases":[],"summary":"bpf: Fix divide-by-zero in btf_struct_walk()","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nbpf: Fix divide-by-zero in btf_struct_walk()\n\nWhen an access goes past the struct and the last member is a flexible\narray, btf_struct_walk() folds the offset back into a single element with\n(off - moff) % t->size, but never checks that the element type has a size.\n\nBTF takes an empty struct, so this in program BTF\n\n\t/* event could be empty */\n\tstruct event {\n #ifdef HAVE_TIMESTAMP\n\t\t__u64 ts;\n #endif\n\t};\n\n\tstruct batch {\n\t\tint nr;\n\t\tstruct event events[];\n\t};\n\ndivides by zero at prog load time. Getting there needs a PTR_TO_BTF_ID that\nis not MEM_ALLOC, e.g. a plain read of a local kptr stashed in a map from a\nsleepable program.\n\nOops: divide error: 0000 [#1] SMP KASAN PTI\nRIP: 0010:btf_struct_walk+0x53f/0x1570\nCall Trace:\n <TASK>\n btf_struct_access+0x42a/0xcd0\n check_ptr_to_btf_access+0x4dc/0x1160\n check_mem_access+0x3a45/0x8740\n check_load_mem+0x36a/0xd10\n do_check_common+0x3ef0/0xb210\n bpf_check+0x6d3b/0x8580\n bpf_prog_load+0xf7c/0x2720\n __sys_bpf+0xa83/0x3690\n __x64_sys_bpf+0xc7/0x150\n x64_sys_call+0x1f3f/0x27e0\n do_syscall_64+0xe5/0x610\n entry_SYSCALL_64_after_hwframe+0x76/0x7e\n </TASK>\n\nReject a zero-sized element type. The fixed array path in the same function\nalready bails out on the same thing:\n\n\tbtf_struct_walk()\n\t...\n\t\t/* skip empty array */\n\t\tif (moff == mtrue_end)\n\t\t\tcontinue;\n\n\t\tmsize /= total_nelems;","categories":["Operating systems"],"product":"Linux","vendor":"Linux","ecosystem":null,"affected_ranges":[{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-98647","source_modified_at":"2026-10-19T09:23:16.870Z","fetched_at":"2026-10-23T18:45:31.882637Z","product":"Linux","vendor":"Linux","versions":[{"version":"9c5f8a1008a121e4c6b24af211034e24b0b63081","lessThan":"1ea3820937f8022e044c41c6e95c84b02741b45f","status":"affected","versionType":"git"},{"version":"9c5f8a1008a121e4c6b24af211034e24b0b63081","lessThan":"172756f02663ad45c889c001c1a8cb4082a01a05","status":"affected","versionType":"git"},{"version":"9c5f8a1008a121e4c6b24af211034e24b0b63081","lessThan":"934e9ba9f8d05656a48624710be67ca4dc8482e6","status":"affected","versionType":"git"},{"version":"9c5f8a1008a121e4c6b24af211034e24b0b63081","lessThan":"63af086cb5fa6f72fd924f86bea4c2194da663a2","status":"affected","versionType":"git"},{"version":"9c5f8a1008a121e4c6b24af211034e24b0b63081","lessThan":"8eb4cd72daad3a9ee63d2281bbdd16ce6d9406b1","status":"affected","versionType":"git"},{"version":"9c5f8a1008a121e4c6b24af211034e24b0b63081","lessThan":"b8fa56722e9c43bcd59c51fe4c7edd5f4158a11b","status":"affected","versionType":"git"},{"version":"9c5f8a1008a121e4c6b24af211034e24b0b63081","lessThan":"b0b3dc66529676228cb938cbcad66920f735c223","status":"affected","versionType":"git"}],"defaultStatus":"unaffected"},{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-98647","source_modified_at":"2026-10-19T09:23:16.870Z","fetched_at":"2026-10-23T18:45:31.882637Z","product":"Linux","vendor":"Linux","versions":[{"version":"5.8","status":"affected"},{"version":"0","lessThan":"5.8","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-2026-98647","source_modified_at":"2026-10-19T09:23:16.870Z","fetched_at":"2026-10-23T18:45:31.882637Z","package":{"name":"Linux","ecosystem":null},"version":"1ea3820937f8022e044c41c6e95c84b02741b45f","basis":"first unaffected version stated in the CVE record"},{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-98647","source_modified_at":"2026-10-19T09:23:16.870Z","fetched_at":"2026-10-23T18:45:31.882637Z","package":{"name":"Linux","ecosystem":null},"version":"172756f02663ad45c889c001c1a8cb4082a01a05","basis":"first unaffected version stated in the CVE record"},{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-98647","source_modified_at":"2026-10-19T09:23:16.870Z","fetched_at":"2026-10-23T18:45:31.882637Z","package":{"name":"Linux","ecosystem":null},"version":"934e9ba9f8d05656a48624710be67ca4dc8482e6","basis":"first unaffected version stated in the CVE record"},{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-98647","source_modified_at":"2026-10-19T09:23:16.870Z","fetched_at":"2026-10-23T18:45:31.882637Z","package":{"name":"Linux","ecosystem":null},"version":"63af086cb5fa6f72fd924f86bea4c2194da663a2","basis":"first unaffected version stated in the CVE record"},{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-98647","source_modified_at":"2026-10-19T09:23:16.870Z","fetched_at":"2026-10-23T18:45:31.882637Z","package":{"name":"Linux","ecosystem":null},"version":"8eb4cd72daad3a9ee63d2281bbdd16ce6d9406b1","basis":"first unaffected version stated in the CVE record"}],"cvss":null,"severity":null,"kev":{"listed":false},"epss":{"probability":0.00172,"percentile":0.06311,"score_date":"2026-10-23"},"published_at":"2026-10-18T15:20:18.360Z","modified_at":"2026-10-19T09:23:16.870Z","provenance":[{"source":"CVE List","url":"https://www.cve.org/CVERecord?id=CVE-2026-98647","fetched_at":"2026-10-23T18:45:31.882637Z","source_modified_at":"2026-10-19T09:23:16.870Z"},{"source":"EPSS","url":"https://api.first.org/data/v1/epss?cve=CVE-2026-98647","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/1ea3820937f8022e044c41c6e95c84b02741b45f"},{"source":"CVE List","url":"https://git.kernel.org/stable/c/172756f02663ad45c889c001c1a8cb4082a01a05"},{"source":"CVE List","url":"https://git.kernel.org/stable/c/934e9ba9f8d05656a48624710be67ca4dc8482e6"},{"source":"CVE List","url":"https://git.kernel.org/stable/c/63af086cb5fa6f72fd924f86bea4c2194da663a2"},{"source":"CVE List","url":"https://git.kernel.org/stable/c/8eb4cd72daad3a9ee63d2281bbdd16ce6d9406b1"},{"source":"CVE List","url":"https://git.kernel.org/stable/c/b8fa56722e9c43bcd59c51fe4c7edd5f4158a11b"},{"source":"CVE List","url":"https://git.kernel.org/stable/c/b0b3dc66529676228cb938cbcad66920f735c223"}],"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":"2026-10-19T09:23:16.870Z","content_hash":"2943095041c8b43211363ad24908190bc15a8c26e21607775c865b35dc870800"}}