{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-43158", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-05-01T14:12:55.990Z", "datePublished": "2026-05-06T11:27:37.848Z", "dateUpdated": "2026-08-05T12:26:14.627Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T12:26:14.627Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nxfs: fix freemap adjustments when adding xattrs to leaf blocks\n\nxfs/592 and xfs/794 both trip this assertion in the leaf block freemap\nadjustment code after ~20 minutes of running on my test VMs:\n\n ASSERT(ichdr->firstused >= ichdr->count * sizeof(xfs_attr_leaf_entry_t)\n\t\t\t\t\t+ xfs_attr3_leaf_hdr_size(leaf));\n\nUpon enabling quite a lot more debugging code, I narrowed this down to\nfsstress trying to set a local extended attribute with namelen=3 and\nvaluelen=71. This results in an entry size of 80 bytes.\n\nAt the start of xfs_attr3_leaf_add_work, the freemap looks like this:\n\ni 0 base 448 size 0 rhs 448 count 46\ni 1 base 388 size 132 rhs 448 count 46\ni 2 base 2120 size 4 rhs 448 count 46\nfirstused = 520\n\nwhere \"rhs\" is the first byte past the end of the leaf entry array.\nThis is inconsistent -- the entries array ends at byte 448, but\nfreemap[1] says there's free space starting at byte 388!\n\nBy the end of the function, the freemap is in worse shape:\n\ni 0 base 456 size 0 rhs 456 count 47\ni 1 base 388 size 52 rhs 456 count 47\ni 2 base 2120 size 4 rhs 456 count 47\nfirstused = 440\n\nImportant note: 388 is not aligned with the entries array element size\nof 8 bytes.\n\nBased on the incorrect freemap, the name area starts at byte 440, which\nis below the end of the entries array! That's why the assertion\ntriggers and the filesystem shuts down.\n\nHow did we end up here? First, recall from the previous patch that the\nfreemap array in an xattr leaf block is not intended to be a\ncomprehensive map of all free space in the leaf block. In other words,\nit's perfectly legal to have a leaf block with:\n\n * 376 bytes in use by the entries array\n * freemap[0] has [base = 376, size = 8]\n * freemap[1] has [base = 388, size = 1500]\n * the space between 376 and 388 is free, but the freemap stopped\n tracking that some time ago\n\nIf we add one xattr, the entries array grows to 384 bytes, and\nfreemap[0] becomes [base = 384, size = 0]. So far, so good. But if we\nadd a second xattr, the entries array grows to 392 bytes, and freemap[0]\ngets pushed up to [base = 392, size = 0]. This is bad, because\nfreemap[1] hasn't been updated, and now the entries array and the free\nspace claim the same space.\n\nThe fix here is to adjust all freemap entries so that none of them\ncollide with the entries array. Note that this fix relies on commit\n2a2b5932db6758 (\"xfs: fix attr leaf header freemap.size underflow\") and\nthe previous patch that resets zero length freemap entries to have\nbase = 0." } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H", "baseScore": 8.8, "baseSeverity": "HIGH" }, "scenarios": [ { "lang": "en", "value": "AV:N - The vulnerable XFS xattr add path is reachable locally via setxattr/fsetxattr, and also remotely on XFS-backed network file servers through in-kernel nfsd NFSv4 SETXATTR and ksmbd xattr/ACL operations that call into vfs_setxattr. Scoring the most severe reasonable deployment, a network file server exposes this over the network.\nAC:L - The attacker controls the xattr names, values, and operation sequence needed to shape the leaf freemap state; this is not a race and does not depend on conditions outside attacker control. The fsstress reproducer indicates the bug can be triggered by ordinary repeated xattr operations.\nPR:L - The attacker needs write permission to a file or directory on the affected XFS filesystem/export, but no administrative capability is required for user.* xattrs. This is basic user/share access rather than real root or CAP_SYS_ADMIN.\nUI:N - No victim action is required once the attacker has access to a writable XFS file or exported share. The attacker can invoke the xattr operation directly.\nS:U - The vulnerability corrupts XFS/kernel filesystem metadata within the same kernel security authority. It does not cross a VM, IOMMU, or sandbox boundary.\nC:H - The bug causes attacker-controlled corruption of xattr leaf entries in a kernel metadata buffer, and those entries drive later xattr parsing offsets and namespace interpretation. Under the required uncertainty rule, this memory/metadata corruption is treated as potentially leveragable for high confidentiality impact.\nI:H - The faulty freemap lets xattr name/value data be allocated on top of the leaf entry array, corrupting XFS metadata and potentially access-control/security xattr state. This is attacker-controlled metadata corruption with documented data-loss potential, so integrity impact is High.\nA:H - The known failure mode trips XFS corruption assertions/verifiers and shuts down the filesystem. A remote or local write-capable attacker can repeat the operation to cause high availability impact." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "fs/xfs/libxfs/xfs_attr_leaf.c" ], "versions": [ { "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2", "lessThan": "d08976725355b9d54d8332fce223fa281cc304a5", "status": "affected", "versionType": "git" }, { "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2", "lessThan": "6a8737afbccc340e718e0b22577312826390be8b", "status": "affected", "versionType": "git" }, { "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2", "lessThan": "a396b3d73d51355e50acdb403ba9c4cae4c1174e", "status": "affected", "versionType": "git" }, { "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2", "lessThan": "38613c01f69e1e77e6b8acab1e8ac665d01c2f15", "status": "affected", "versionType": "git" }, { "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2", "lessThan": "ef42a8766ff3fdf51cf72fb36d0859c09d134478", "status": "affected", "versionType": "git" }, { "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2", "lessThan": "43f3b18679615a93bd848afde3602ba160637a46", "status": "affected", "versionType": "git" }, { "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2", "lessThan": "24ce71852f2cee6581e2cbebc15489ed52bf63b7", "status": "affected", "versionType": "git" }, { "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2", "lessThan": "3eefc0c2b78444b64feeb3783c017d6adc3cd3ce", "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/libxfs/xfs_attr_leaf.c" ], "versions": [ { "version": "2.6.12", "status": "affected" }, { "version": "0", "lessThan": "2.6.12", "status": "unaffected", "versionType": "semver" }, { "version": "5.10.252", "lessThanOrEqual": "5.10.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.15.202", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.165", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.128", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.75", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.16", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.19.6", "lessThanOrEqual": "6.19.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.0", "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": "2.6.12", "versionEndExcluding": "5.10.252" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.12", "versionEndExcluding": "5.15.202" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.12", "versionEndExcluding": "6.1.165" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.12", "versionEndExcluding": "6.6.128" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.12", "versionEndExcluding": "6.12.75" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.12", "versionEndExcluding": "6.18.16" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.12", "versionEndExcluding": "6.19.6" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.12", "versionEndExcluding": "7.0" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/d08976725355b9d54d8332fce223fa281cc304a5" }, { "url": "https://git.kernel.org/stable/c/6a8737afbccc340e718e0b22577312826390be8b" }, { "url": "https://git.kernel.org/stable/c/a396b3d73d51355e50acdb403ba9c4cae4c1174e" }, { "url": "https://git.kernel.org/stable/c/38613c01f69e1e77e6b8acab1e8ac665d01c2f15" }, { "url": "https://git.kernel.org/stable/c/ef42a8766ff3fdf51cf72fb36d0859c09d134478" }, { "url": "https://git.kernel.org/stable/c/43f3b18679615a93bd848afde3602ba160637a46" }, { "url": "https://git.kernel.org/stable/c/24ce71852f2cee6581e2cbebc15489ed52bf63b7" }, { "url": "https://git.kernel.org/stable/c/3eefc0c2b78444b64feeb3783c017d6adc3cd3ce" } ], "title": "xfs: fix freemap adjustments when adding xattrs to leaf blocks", "x_generator": { "engine": "bippy-1.2.0" } } } }