{"schema":"threatline.record/2","record":{"id":"CVE-2026-97926","aliases":[],"summary":"ufs: validate cylinder group metadata before caching it","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nufs: validate cylinder group metadata before caching it\n\nufs_read_cylinder() copies the cylinder group index and the rotor\npositions straight from the on-disk group and caches them without any\ncheck:\n\n\tucpi->c_cgx    = fs32_to_cpu(sb, ucg->cg_cgx);\n\tucpi->c_rotor  = fs32_to_cpu(sb, ucg->cg_rotor);\n\tucpi->c_frotor = fs32_to_cpu(sb, ucg->cg_frotor);\n\tucpi->c_irotor = fs32_to_cpu(sb, ucg->cg_irotor);\n\nThey are then used as indices during allocation and free:\n\n  - c_cgx indexes the cylinder summary array as\n    UFS_SB(sb)->fs_cs(ucpi->c_cgx), so a value past s_ncg writes a 32\n    bit count outside the s_csp allocation.\n\n  - c_frotor becomes a bitmap scan start, start = c_frotor >> 3, and\n    then length = ((s_fpg + 7) >> 3) - start. A start beyond the block\n    bitmap wraps the unsigned length to a huge value, so ubh_scanc()\n    walks far past the cylinder group buffers. c_irotor drives the\n    inode bitmap the same way.\n\nA crafted image can set any of these freely, turning an ordinary\nallocation into an out of bounds access.\n\nReject a cylinder group whose recorded index does not match the group\nbeing read, or whose rotors fall outside the group, before the metadata\nis cached. Valid filesystems keep cg_cgx equal to the group number and\nthe rotors within the group, so only malformed images are rejected.","categories":["Operating systems"],"product":"Linux","vendor":"Linux","ecosystem":null,"affected_ranges":[{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-97926","source_modified_at":"2026-10-19T09:10:53.241Z","fetched_at":"2026-10-23T18:45:31.882637Z","product":"Linux","vendor":"Linux","versions":[{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","lessThan":"88cccb6beba136b73f0caf80e59457e1b3c0ca1e","status":"affected","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","lessThan":"f560a9e33365c460827c735fd86435f9213f1aed","status":"affected","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","lessThan":"e4c5cc9688c3e69d07d888853388549ae26c0521","status":"affected","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","lessThan":"58c0c414b2b8d099d33da494a354fa836ca6c10b","status":"affected","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","lessThan":"5902a95066883cf96fa15b2680694fc5dd0c7d11","status":"affected","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","lessThan":"87b12dc360a002eb2d498aa4f01e84347019612d","status":"affected","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","lessThan":"abde9eb33106850dfa367ad3965d3588bb8558d5","status":"affected","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","lessThan":"c9d263be26806d388129fab8c6904bed197fc6af","status":"affected","versionType":"git"}],"defaultStatus":"unaffected"},{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-97926","source_modified_at":"2026-10-19T09:10:53.241Z","fetched_at":"2026-10-23T18:45:31.882637Z","product":"Linux","vendor":"Linux","versions":[{"version":"2.6.12","status":"affected"},{"version":"0","lessThan":"2.6.12","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":"6.12.111","lessThanOrEqual":"6.12.*","status":"unaffected","versionType":"semver"},{"version":"6.18.53","lessThanOrEqual":"6.18.*","status":"unaffected","versionType":"semver"},{"version":"7.2.7","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-2026-97926","source_modified_at":"2026-10-19T09:10:53.241Z","fetched_at":"2026-10-23T18:45:31.882637Z","package":{"name":"Linux","ecosystem":null},"version":"88cccb6beba136b73f0caf80e59457e1b3c0ca1e","basis":"first unaffected version stated in the CVE record"},{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-97926","source_modified_at":"2026-10-19T09:10:53.241Z","fetched_at":"2026-10-23T18:45:31.882637Z","package":{"name":"Linux","ecosystem":null},"version":"58c0c414b2b8d099d33da494a354fa836ca6c10b","basis":"first unaffected version stated in the CVE record"},{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-97926","source_modified_at":"2026-10-19T09:10:53.241Z","fetched_at":"2026-10-23T18:45:31.882637Z","package":{"name":"Linux","ecosystem":null},"version":"5902a95066883cf96fa15b2680694fc5dd0c7d11","basis":"first unaffected version stated in the CVE record"},{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-97926","source_modified_at":"2026-10-19T09:10:53.241Z","fetched_at":"2026-10-23T18:45:31.882637Z","package":{"name":"Linux","ecosystem":null},"version":"87b12dc360a002eb2d498aa4f01e84347019612d","basis":"first unaffected version stated in the CVE record"}],"cvss":7,"severity":"High","kev":{"listed":false},"epss":{"probability":0.00154,"percentile":0.04152,"score_date":"2026-10-23"},"published_at":"2026-09-25T10:22:44.197Z","modified_at":"2026-10-19T09:10:53.241Z","provenance":[{"source":"CVE List","url":"https://www.cve.org/CVERecord?id=CVE-2026-97926","fetched_at":"2026-10-23T18:45:31.882637Z","source_modified_at":"2026-10-19T09:10:53.241Z"},{"source":"EPSS","url":"https://api.first.org/data/v1/epss?cve=CVE-2026-97926","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/88cccb6beba136b73f0caf80e59457e1b3c0ca1e"},{"source":"CVE List","url":"https://git.kernel.org/stable/c/f560a9e33365c460827c735fd86435f9213f1aed"},{"source":"CVE List","url":"https://git.kernel.org/stable/c/e4c5cc9688c3e69d07d888853388549ae26c0521"},{"source":"CVE List","url":"https://git.kernel.org/stable/c/58c0c414b2b8d099d33da494a354fa836ca6c10b"},{"source":"CVE List","url":"https://git.kernel.org/stable/c/5902a95066883cf96fa15b2680694fc5dd0c7d11"},{"source":"CVE List","url":"https://git.kernel.org/stable/c/87b12dc360a002eb2d498aa4f01e84347019612d"},{"source":"CVE List","url":"https://git.kernel.org/stable/c/abde9eb33106850dfa367ad3965d3588bb8558d5"},{"source":"CVE List","url":"https://git.kernel.org/stable/c/c9d263be26806d388129fab8c6904bed197fc6af"}],"locations":[],"motoko_assessment":{"status":"requires_architecture_review","automatic_remediation":false},"cve_state":"PUBLISHED","cvss_source":"CVE List","classification":{"method":"product-first software-layer rules","rules_version":"2.1","matched_on":"product","confidence":"heuristic","reviewed":false},"change_timestamp":"2026-10-19T09:10:53.241Z","content_hash":"a79af76f85b5db2dcf35bf325360b712890b6698b24d75e44e68f29a0a2cd54b"}}