{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-98443", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-09-25T10:25:14.349Z", "datePublished": "2026-10-18T15:14:53.597Z", "dateUpdated": "2026-10-24T14:08:51.954Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-10-24T14:08:51.954Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nxfs: fix cursor and pointer handling when recovering iunlink buckets\n\nLOLLM pointed out a bug in xlog_recover_iunlink_bucket:\n\n1. We don't null out prev_ip after releasing it, which can lead to UAF\n problems if the inodegc flush call in the loop fails.\n\nat which point I noticed even more bugs:\n\n2. If the inodegc flush inside the loop fails, we also leak @ip.\n\n3. We set prev_agino to agino having already advanced agino, which\n results in inodes with i_prev_unlinked set to itself.\n\n4. If we exit the bottom of the loop with prev_ip set, then prev_ip\n aliases ip and we also set its i_prev_unlinked to itself.\n\nBugs 3 and 4 introduce loops into the unlinked list, though these loops\ndon't surface because we immediately flush each unlinked inode after\nloading it.\n\nFix all of these issues." } ], "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 - Malformed agi_unlinked, di_next_unlinked, and inode-fork data enter from a local XFS image when mount(2) reaches xlog_recover_iunlink_bucket through xfs_log_mount_finish and xlog_recover_finish; no remote protocol carries these bytes.\nAC:L - The image author can create a dirty log, two inodes in one unlinked bucket, and corrupt external btree metadata that makes xfs_inactive fail through xfs_inodegc_flush. This deterministically enters the stale-prev_ip error path without requiring an uncontrollable hardware fault.\nPR:N - The attacker only creates and supplies the XFS image, requiring no target account or capability. XFS omits FS_USERNS_MOUNT, so the privileged mount_capable check applies to the interacting victim and is captured by UI:R.\nUI:R - A victim or administrator must mount the attacker-supplied dirty XFS image so xfs_log_mount_finish invokes xlog_recover_finish and the patched xlog_recover_iunlink_bucket.\nS:U - The stale xfs_inode and resulting memory corruption affect the mounting host kernel within its existing security authority; no VM, IOMMU, or other isolation boundary is crossed.\nC:H - After xfs_inodegc_flush makes prev_ip reclaimable, the stale pointer can reference an xfs_inode_cache object reclaimed and replaced before the second xfs_irele; reuse and secondary UAF of the replacement inode support kernel-memory disclosure.\nI:H - The second xfs_irele can decrement i_count in a reused xfs_inode, prematurely destroying a live replacement inode and producing secondary use-after-free memory corruption exploitable for control-flow hijacking.\nA:H - The stale xfs_irele can dereference a freed inode or underflow its reference count; DEBUG_VFS BUGs on the invalid inode state/count, while non-debug builds can corrupt a replacement inode and later oops or panic." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "fs/xfs/xfs_log_recover.c" ], "versions": [ { "version": "04755d2e5821b3afbaadd09fe5df58d04de36484", "lessThan": "47a948ba653a463d429e02fda2f06a3d6b78666d", "status": "affected", "versionType": "git" }, { "version": "04755d2e5821b3afbaadd09fe5df58d04de36484", "lessThan": "8c9d5b8a96d6b93eb24e07b4163c89341ba29bd1", "status": "affected", "versionType": "git" }, { "version": "04755d2e5821b3afbaadd09fe5df58d04de36484", "lessThan": "66a2179d02668f8df44b1a249899006f3ba38ea0", "status": "affected", "versionType": "git" }, { "version": "04755d2e5821b3afbaadd09fe5df58d04de36484", "lessThan": "961c717e6bf0e53c2c2b1fe4aef1add9390fedab", "status": "affected", "versionType": "git" }, { "version": "04755d2e5821b3afbaadd09fe5df58d04de36484", "lessThan": "65f39d09d73718611cee40399179323b5d4ead00", "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/xfs/xfs_log_recover.c" ], "versions": [ { "version": "6.0", "status": "affected" }, { "version": "0", "lessThan": "6.0", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.160", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.113", "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" } ] } ], "cpeApplicability": [ { "nodes": [ { "operator": "OR", "negate": false, "cpeMatch": [ { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.0", "versionEndExcluding": "6.6.160" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.0", "versionEndExcluding": "6.12.113" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.0", "versionEndExcluding": "6.18.55" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.0", "versionEndExcluding": "7.2.9" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.0", "versionEndExcluding": "7.3" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/47a948ba653a463d429e02fda2f06a3d6b78666d" }, { "url": "https://git.kernel.org/stable/c/8c9d5b8a96d6b93eb24e07b4163c89341ba29bd1" }, { "url": "https://git.kernel.org/stable/c/66a2179d02668f8df44b1a249899006f3ba38ea0" }, { "url": "https://git.kernel.org/stable/c/961c717e6bf0e53c2c2b1fe4aef1add9390fedab" }, { "url": "https://git.kernel.org/stable/c/65f39d09d73718611cee40399179323b5d4ead00" } ], "title": "xfs: fix cursor and pointer handling when recovering iunlink buckets", "x_generator": { "engine": "bippy-1.2.0" } } } }