blob: e46d9ff38e8d1f218f7972163dd2b31efba42a63 [file]
{
"containers": {
"cna": {
"providerMetadata": {
"orgId": "f4215fc3-5b6b-47ff-a258-f7189bd81038"
},
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nf2fs: fix fsck inconsistency caused by incorrect nat_entry flag usage\n\nf2fs_need_dentry_mark() reads nat_entry flags without mutual exclusion\nwith the checkpoint path, which can result in an incorrect inode block\nmarking state. The scenario is as follows:\n\ncreate & write & fsync 'file A' write checkpoint\n- f2fs_do_sync_file // inline inode\n - f2fs_write_inode // inode folio is dirty\n - f2fs_write_checkpoint\n - f2fs_flush_merged_writes\n - f2fs_sync_node_pages\n - f2fs_fsync_node_pages // no dirty node\n - f2fs_need_inode_block_update // return true\n - f2fs_fsync_node_pages // inode dirtied\n - f2fs_need_dentry_mark //return true\n - f2fs_flush_nat_entries\n - f2fs_write_checkpoint end\n - __write_node_folio // inode with DENT_BIT_SHIFT set\n SPO, \"fsck --dry-run\" find inode has already checkpointed but still\n with DENT_BIT_SHIFT set\n\nThe state observed by f2fs_need_dentry_mark() can differ from the state\nobserved in __write_node_folio() after acquiring sbi->node_write. The\nroot cause is that the semantics of IS_CHECKPOINTED and\nHAS_FSYNCED_INODE are only guaranteed after the checkpoint write has\nfully completed.\n\nThis patch moves set_dentry_mark() into __write_node_folio() and\nprotects it with the sbi->node_write lock."
}
],
"metrics": [
{
"cvssV3_1": {
"version": "3.1",
"vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H",
"baseScore": 7.1,
"baseSeverity": "HIGH"
},
"scenarios": [
{
"lang": "en",
"value": "AV:L - The bug is reached via local filesystem syscalls (fsync/fdatasync on a writable file) on an F2FS mount. F2FS is primarily deployed on local flash storage (Android /data, ChromeOS, embedded), not as a network-facing attack surface.\nAC:L - An attacker controls both sides of the race by concurrently fsyncing an inline inode while triggering a checkpoint (e.g., via sync(2), heavy writeback, or background checkpoint/GC threads). No conditions outside attacker influence are required beyond routine concurrent I/O.\nPR:L - Exploitation requires only unprivileged write access to files on the F2FS filesystem plus the ability to issue fsync/sync syscalls. No CAP_SYS_ADMIN, mount privileges, or init-namespace root are needed.\nUI:N - No victim interaction is required; the attacker performs the write and fsync operations on files they can already modify.\nS:U - The impact is confined to F2FS on-disk metadata and recovery semantics within the same kernel/filesystem security boundary. There is no VM escape, sandbox breakout, or cross-authority boundary crossing.\nC:N - The bug causes incorrect setting of the DENT_BIT_SHIFT recovery flag on a node block. It does not read kernel memory, leak pointers, or disclose data beyond what the attacker already wrote.\nI:H - The race writes incorrect dentry recovery metadata to disk (checkpointed inode still marked with DENT_BIT_SHIFT), producing fsck-detectable filesystem inconsistency and potentially breaking roll-forward recovery of fsynced data after sudden power-off.\nA:H - Corrupted recovery metadata can cause mount-time recovery failures (as seen in the related atomic-write variant returning -EINVAL from f2fs_recover_inode_page) and fsck-detected inconsistency after power loss, degrading filesystem availability on F2FS-backed systems such as Android devices."
}
]
}
],
"affected": [
{
"product": "Linux",
"vendor": "Linux",
"defaultStatus": "unaffected",
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"programFiles": [
"fs/f2fs/node.c"
],
"versions": [
{
"version": "88bd02c9472a166b706284a34a84f1243322d782",
"lessThan": "bedb710b63ae1bd617e65d0a8cf6cea1200b3753",
"status": "affected",
"versionType": "git"
},
{
"version": "88bd02c9472a166b706284a34a84f1243322d782",
"lessThan": "b28a83ea4934215b5de906c3ee4fbfbc651573e0",
"status": "affected",
"versionType": "git"
},
{
"version": "88bd02c9472a166b706284a34a84f1243322d782",
"lessThan": "019f9dda7f66e55eb94cd32e1d3fff5835f73fbc",
"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/f2fs/node.c"
],
"versions": [
{
"version": "3.18",
"status": "affected"
},
{
"version": "0",
"lessThan": "3.18",
"status": "unaffected",
"versionType": "semver"
},
{
"version": "6.18.30",
"lessThanOrEqual": "6.18.*",
"status": "unaffected",
"versionType": "semver"
},
{
"version": "7.0.7",
"lessThanOrEqual": "7.0.*",
"status": "unaffected",
"versionType": "semver"
},
{
"version": "7.1",
"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": "3.18",
"versionEndExcluding": "6.18.30"
},
{
"vulnerable": true,
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionStartIncluding": "3.18",
"versionEndExcluding": "7.0.7"
},
{
"vulnerable": true,
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionStartIncluding": "3.18",
"versionEndExcluding": "7.1"
}
]
}
]
}
],
"references": [
{
"url": "https://git.kernel.org/stable/c/bedb710b63ae1bd617e65d0a8cf6cea1200b3753"
},
{
"url": "https://git.kernel.org/stable/c/b28a83ea4934215b5de906c3ee4fbfbc651573e0"
},
{
"url": "https://git.kernel.org/stable/c/019f9dda7f66e55eb94cd32e1d3fff5835f73fbc"
}
],
"title": "f2fs: fix fsck inconsistency caused by incorrect nat_entry flag usage",
"x_generator": {
"engine": "bippy-1.2.0"
}
}
},
"cveMetadata": {
"assignerOrgId": "f4215fc3-5b6b-47ff-a258-f7189bd81038",
"cveId": "CVE-2026-53368",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.1.1"
}