{"id":"CVE-2026-90204","state":"PUBLISHED","title":"ocfs2: validate DIO orphan slot during inode read","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nocfs2: validate DIO orphan slot during inode read\n\n[BUG]\nA corrupted append-DIO dinode (high byte at offset 0xa1\ncorrupted from 0 to 1) can carry an i_dio_orphaned_slot\noutside the mounted filesystem slot range and trigger a\nuse-after-free error:\n\nBUG: KASAN: slab-use-after-free in ocfs2_get_system_file_inode+0x780/0x820 fs/ocfs2/sysfile.c:102\nRead of size 8 at addr ffff88800b767c00 by task kworker/u8:3/85\nCall Trace:\n ...\n ocfs2_get_system_file_inode+0x780/0x820 fs/ocfs2/sysfile.c:102\n ocfs2_wipe_inode+0x292/0xf70 fs/ocfs2/inode.c:840\n ocfs2_delete_inode fs/ocfs2/inode.c:1155 [inline]\n ocfs2_evict_inode+0x6c9/0x1170 fs/ocfs2/inode.c:1295\n evict+0x38e/0x8f0 fs/inode.c:810\n iput_final fs/inode.c:1914 [inline]\n iput fs/inode.c:1966 [inline]\n iput+0x55b/0x8b0 fs/inode.c:1926\n ocfs2_recover_orphans+0x610/0xe40 fs/ocfs2/journal.c:2374\n ocfs2_complete_recovery+0x5af/0xd00 fs/ocfs2/journal.c:1373\n ...\n\n[CAUSE]\nocfs2_del_inode_from_orphan() uses i_dio_orphaned_slot to index the\nslot-local system inode cache. The dinode validator does not check\nthis active slot, so an out-of-range value produces an invalid cache\nentry pointer that is dereferenced as an inode pointer.\n\n[FIX]\nReject an active i_dio_orphaned_slot outside the slot range during\ndinode validation, before DIO orphan recovery can consume it.","publishedAt":"2026-09-17T16:07:20.845Z","updatedAt":"2026-10-30T12:34:44.238Z","severity":{"score":7.8,"label":"High","version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H","source":"Linux"},"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"06ee5c75b57564435933fc0ffa72dc18a2fda0e7","status":"affected","lessThan":"b5fcd0aa818e08ede9a1d705ffadb0a19b565ebc","versionType":"git"},{"version":"06ee5c75b57564435933fc0ffa72dc18a2fda0e7","status":"affected","lessThan":"eacdd27ca829747d4372fbae8617151072a4d1e5","versionType":"git"},{"version":"06ee5c75b57564435933fc0ffa72dc18a2fda0e7","status":"affected","lessThan":"8f7a2c5cf23d437acab7f3e739bfcad0f443c554","versionType":"git"},{"version":"06ee5c75b57564435933fc0ffa72dc18a2fda0e7","status":"affected","lessThan":"e35fa6eb4d2a39f8049f62361a4b44930882b5f8","versionType":"git"},{"version":"06ee5c75b57564435933fc0ffa72dc18a2fda0e7","status":"affected","lessThan":"418e0ae42fa769d354b15e62c01a00413024755b","versionType":"git"},{"version":"06ee5c75b57564435933fc0ffa72dc18a2fda0e7","status":"affected","lessThan":"bb88131c9831075b8dc08cdd375743e5d44c7ca2","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/ocfs2/inode.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"4.0","status":"affected"},{"version":"0","status":"unaffected","lessThan":"4.0","versionType":"semver"},{"version":"6.1.191","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.160","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.114","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.52","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.2.6","status":"unaffected","lessThanOrEqual":"7.2.*","versionType":"semver"},{"version":"7.3","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/ocfs2/inode.c"]}],"references":["https://git.kernel.org/stable/c/b5fcd0aa818e08ede9a1d705ffadb0a19b565ebc","https://git.kernel.org/stable/c/eacdd27ca829747d4372fbae8617151072a4d1e5","https://git.kernel.org/stable/c/8f7a2c5cf23d437acab7f3e739bfcad0f443c554","https://git.kernel.org/stable/c/e35fa6eb4d2a39f8049f62361a4b44930882b5f8","https://git.kernel.org/stable/c/418e0ae42fa769d354b15e62c01a00413024755b","https://git.kernel.org/stable/c/bb88131c9831075b8dc08cdd375743e5d44c7ca2"],"weaknesses":[],"ingestedAt":"2026-10-30T12:54:04.478Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/90xxx/CVE-2026-90204.json","commit":"1f312381e38164a43607eebab851b151dd16861e","baselineCommit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-90204","state":"PUBLISHED","datePublished":"2026-09-17T16:07:20.845Z","dateUpdated":"2026-10-30T12:34:44.238Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-09-11T19:38:34.792Z"},"containers":{"cna":{"title":"ocfs2: validate DIO orphan slot during inode read","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nocfs2: validate DIO orphan slot during inode read\n\n[BUG]\nA corrupted append-DIO dinode (high byte at offset 0xa1\ncorrupted from 0 to 1) can carry an i_dio_orphaned_slot\noutside the mounted filesystem slot range and trigger a\nuse-after-free error:\n\nBUG: KASAN: slab-use-after-free in ocfs2_get_system_file_inode+0x780/0x820 fs/ocfs2/sysfile.c:102\nRead of size 8 at addr ffff88800b767c00 by task kworker/u8:3/85\nCall Trace:\n ...\n ocfs2_get_system_file_inode+0x780/0x820 fs/ocfs2/sysfile.c:102\n ocfs2_wipe_inode+0x292/0xf70 fs/ocfs2/inode.c:840\n ocfs2_delete_inode fs/ocfs2/inode.c:1155 [inline]\n ocfs2_evict_inode+0x6c9/0x1170 fs/ocfs2/inode.c:1295\n evict+0x38e/0x8f0 fs/inode.c:810\n iput_final fs/inode.c:1914 [inline]\n iput fs/inode.c:1966 [inline]\n iput+0x55b/0x8b0 fs/inode.c:1926\n ocfs2_recover_orphans+0x610/0xe40 fs/ocfs2/journal.c:2374\n ocfs2_complete_recovery+0x5af/0xd00 fs/ocfs2/journal.c:1373\n ...\n\n[CAUSE]\nocfs2_del_inode_from_orphan() uses i_dio_orphaned_slot to index the\nslot-local system inode cache. The dinode validator does not check\nthis active slot, so an out-of-range value produces an invalid cache\nentry pointer that is dereferenced as an inode pointer.\n\n[FIX]\nReject an active i_dio_orphaned_slot outside the slot range during\ndinode validation, before DIO orphan recovery can consume it."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"06ee5c75b57564435933fc0ffa72dc18a2fda0e7","status":"affected","lessThan":"b5fcd0aa818e08ede9a1d705ffadb0a19b565ebc","versionType":"git"},{"version":"06ee5c75b57564435933fc0ffa72dc18a2fda0e7","status":"affected","lessThan":"eacdd27ca829747d4372fbae8617151072a4d1e5","versionType":"git"},{"version":"06ee5c75b57564435933fc0ffa72dc18a2fda0e7","status":"affected","lessThan":"8f7a2c5cf23d437acab7f3e739bfcad0f443c554","versionType":"git"},{"version":"06ee5c75b57564435933fc0ffa72dc18a2fda0e7","status":"affected","lessThan":"e35fa6eb4d2a39f8049f62361a4b44930882b5f8","versionType":"git"},{"version":"06ee5c75b57564435933fc0ffa72dc18a2fda0e7","status":"affected","lessThan":"418e0ae42fa769d354b15e62c01a00413024755b","versionType":"git"},{"version":"06ee5c75b57564435933fc0ffa72dc18a2fda0e7","status":"affected","lessThan":"bb88131c9831075b8dc08cdd375743e5d44c7ca2","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/ocfs2/inode.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"4.0","status":"affected"},{"version":"0","status":"unaffected","lessThan":"4.0","versionType":"semver"},{"version":"6.1.191","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.160","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.114","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.52","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.2.6","status":"unaffected","lessThanOrEqual":"7.2.*","versionType":"semver"},{"version":"7.3","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/ocfs2/inode.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/b5fcd0aa818e08ede9a1d705ffadb0a19b565ebc"},{"url":"https://git.kernel.org/stable/c/eacdd27ca829747d4372fbae8617151072a4d1e5"},{"url":"https://git.kernel.org/stable/c/8f7a2c5cf23d437acab7f3e739bfcad0f443c554"},{"url":"https://git.kernel.org/stable/c/e35fa6eb4d2a39f8049f62361a4b44930882b5f8"},{"url":"https://git.kernel.org/stable/c/418e0ae42fa769d354b15e62c01a00413024755b"},{"url":"https://git.kernel.org/stable/c/bb88131c9831075b8dc08cdd375743e5d44c7ca2"}],"metrics":[{"cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H","baseScore":7.8,"baseSeverity":"HIGH"},"scenarios":[{"lang":"en","value":"AV:L - The bad i_dio_orphaned_slot is an on-disk ocfs2_dinode field (offset 0xa0) consumed by ocfs2_del_inode_from_orphan() after ocfs2_validate_inode_block() along ocfs2_fill_super→ocfs2_complete_mount_recovery→ocfs2_recover_orphans (or ocfs2_add_inode_to_orphan on append DIO). No network protocol carries this slot.\nAC:L - A dinode with OCFS2_DIO_ORPHANED_FL and i_dio_orphaned_slot >= osb->max_slots (the reported 0xa1 0→1 flip yields slot 256) makes get_local_system_inode() index slot*NUM_LOCAL_SYSTEM_INODES past the kzalloc(max_slots*NUM_LOCAL_SYSTEM_INODES) cache and igrab the out-of-range pointer with no race.\nPR:N - ocfs2_fs_type lacks FS_USERNS_MOUNT, so mount_capable() requires init-namespace CAP_SYS_ADMIN. The higher-severity case is a crafted loop/LUN image whose recovery runs when an administrator mounts it, so the attacker needs no account or capability on the victim.\nUI:R - The attacker-supplied ocfs2 image must be mounted via ocfs2_fill_super so ocfs2_complete_mount_recovery() can walk DIO orphan dirents and call ocfs2_del_inode_from_orphan() on the forged i_dio_orphaned_slot. That mount is the required victim action.\nS:U - igrab() of the out-of-range local_system_inodes[] pointer and later ocfs2_inode_lock() stay inside the kernel that mounted the volume; this is not a KVM/Xen guest-to-host escape or IOMMU/DMA bypass.\nC:H - get_local_system_inode() reads an 8-byte inode pointer past the slot-local cache, then igrab() and ocfs2_inode_lock() treat it as a live inode. KASAN reported slab-use-after-free in ocfs2_get_system_file_inode(); a UAF inode object yields an arbitrary kernel read.\nI:H - After igrab() on the OOB/UAF pointer, ocfs2_del_inode_from_orphan() takes inode_lock and ocfs2_inode_lock on that object and journals orphan-dir mutations through it, which is a type-confused write/control-flow primitive on a freed or adjacent heap object.\nA:H - igrab() on a garbage or I_FREEING pointer hits BUG_ON(!inode) in ocfs2_get_system_file_inode() or the KASAN UAF oops shown on the ocfs2_recover_orphans mount-recovery path, which is a kernel crash."}]}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-10-30T12:34:44.238Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.0","versionEndExcluding":"6.1.191"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.0","versionEndExcluding":"6.6.160"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.0","versionEndExcluding":"6.12.114"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.0","versionEndExcluding":"6.18.52"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.0","versionEndExcluding":"7.2.6"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.0","versionEndExcluding":"7.3"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}}}}}