{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-90320", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-09-11T19:38:34.802Z", "datePublished": "2026-09-17T16:08:37.497Z", "dateUpdated": "2026-10-21T12:50:55.685Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-10-21T12:50:55.685Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nocfs2: validate external xattr entries when reading metadata\n\nocfs2_validate_xattr_block() checks the xattr block header before the\nblock reaches higher-level xattr users, but it does not verify that a\nnon-indexed block's xh_count and entry offsets fit inside the block. \nIndexed buckets likewise reach list/get consumers after ECC without an\nentry-bounds check.\n\nUse the flat xattr entry validator for non-indexed external xattr blocks,\nand use a bucket-specific validator for indexed buckets at metadata read\ntime. The bucket validator keeps the entry array bounded by the first\nbucket block while checking name/value offsets against the bucket block\nthey target.\n\nReject corrupted external xattr metadata before listxattr() or getxattr()\ncan walk out-of-range entry arrays or name/value offsets.\n\nValidation reproduced this kernel report:\nBUG: KASAN: use-after-free in ocfs2_xattr_list_entries+0xd7/0x190\nRead of size 1 at addr ffff88810a654007 by task ocfs2_xattr_lis/630\nCall Trace:\n dump_stack_lvl+0x66/0xa0\n print_report+0xce/0x630\n kasan_report+0xe0/0x110\n ocfs2_xattr_list_entries+0xd7/0x190\n ocfs2_listxattr+0x3f6/0x610\n listxattr+0x90/0xe0\n path_listxattrat+0xed/0x220\n do_syscall_64+0x115/0x6a0\n entry_SYSCALL_64_after_hwframe+0x77/0x7f" } ], "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 attacker-controlled bytes are on-disk ocfs2_xattr_header.xh_count and ocfs2_xattr_entry.xe_name_offset in an external xattr block or bucket, read by ocfs2_read_xattr_block()/ocfs2_read_xattr_bucket() when path_listxattrat() reaches ocfs2_listxattr()→ocfs2_xattr_block_list(); no network protocol carries those fields.\nAC:L - The crafted image fully controls xh_count and xe_name_offset; once the volume is mounted, ocfs2_xattr_list_entries() walks header->xh_entries[i] and forms name from xe_name_offset with no race, matching the deterministic KASAN UAF in that function.\nPR:N - ocfs2_xa_set() writes well-formed entry arrays, so planting a bad xh_count needs a crafted image; ocfs2_fs_type has no FS_USERNS_MOUNT, so the attacker cannot self-mount, and after the victim's ocfs2_fill_super() vfs_listxattr() calls ocfs2_listxattr() with no MAY_READ/DAC check.\nUI:R - The malformed external xattr header is inert until a victim or admin mounts the crafted OCFS2 image through ocfs2_fill_super(); listxattr/getxattr on that volume is the follow-on action that reaches ocfs2_xattr_list_entries() or ocfs2_xattr_block_get().\nS:U - The OOB/UAF is in kernel buffers for the ocfs2_xattr_block or xattr bucket on the same host that parsed the metadata and does not cross a VM, IOMMU, or guest-to-host boundary.\nC:H - ocfs2_xattr_list_entries() indexes xh_entries with unbounded on-disk xh_count, then memcpy's xe_name_len bytes from header+xe_name_offset into the listxattr buffer (copy_to_user); the repro is a KASAN UAF read of size 1 there, disclosing adjacent kernel memory.\nI:H - The same unvalidated xh_count/xe_name_offset are a kernel UAF/OOB walk; ocfs2_xa_bucket_add_entry() memmove's count*sizeof(ocfs2_xattr_entry) on setxattr and ocfs2_xattr_block_get() memcpy's xe_value_size from the unvalidated name offset, giving write/control-flow primitives.\nA:H - The KASAN report is a use-after-free in ocfs2_xattr_list_entries() from listxattr; the unbounded xh_count walk and ocfs2_xattr_bucket_get_name_value() indexing bu_bhs[name_offset>>blocksize_bits] past bu_blocks can oops or panic the node." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "fs/ocfs2/xattr.c" ], "versions": [ { "version": "cf1d6c763fbcb115263114302485ad17e7933d87", "lessThan": "dc5778dbd0b6c411107a0e37e913a94b3c2f2728", "status": "affected", "versionType": "git" }, { "version": "cf1d6c763fbcb115263114302485ad17e7933d87", "lessThan": "ee4ef26927e967ea699b3f0d7ecf97ce044fbc79", "status": "affected", "versionType": "git" }, { "version": "cf1d6c763fbcb115263114302485ad17e7933d87", "lessThan": "9f4129b6905b7d638bbc9eb8013c3989cbe30b7e", "status": "affected", "versionType": "git" }, { "version": "cf1d6c763fbcb115263114302485ad17e7933d87", "lessThan": "2cf82b46d5e43be0dfbaac7fa1073cec2fc1f5e6", "status": "affected", "versionType": "git" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "fs/ocfs2/xattr.c" ], "versions": [ { "version": "2.6.28", "status": "affected" }, { "version": "0", "lessThan": "2.6.28", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.160", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.114", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.2.6", "lessThanOrEqual": "7.2.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.3", "lessThanOrEqual": "*", "status": "unaffected", "versionType": "original_commit_for_fix" } ] } ], "cpeApplicability": [ { "nodes": [ { "operator": "OR", "negate": false, "cpeMatch": [ { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.28", "versionEndExcluding": "6.6.160" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.28", "versionEndExcluding": "6.12.114" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.28", "versionEndExcluding": "7.2.6" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.28", "versionEndExcluding": "7.3" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/dc5778dbd0b6c411107a0e37e913a94b3c2f2728" }, { "url": "https://git.kernel.org/stable/c/ee4ef26927e967ea699b3f0d7ecf97ce044fbc79" }, { "url": "https://git.kernel.org/stable/c/9f4129b6905b7d638bbc9eb8013c3989cbe30b7e" }, { "url": "https://git.kernel.org/stable/c/2cf82b46d5e43be0dfbaac7fa1073cec2fc1f5e6" } ], "title": "ocfs2: validate external xattr entries when reading metadata", "x_generator": { "engine": "bippy-1.2.0" } } } }