ghsa-x383-8hmc-j634
Vulnerability from github
In the Linux kernel, the following vulnerability has been resolved:
ext4: detect invalid INLINE_DATA + EXTENTS flag combination
syzbot reported a BUG_ON in ext4_es_cache_extent() when opening a verity file on a corrupted ext4 filesystem mounted without a journal.
The issue is that the filesystem has an inode with both the INLINE_DATA and EXTENTS flags set:
EXT4-fs error (device loop0): ext4_cache_extents:545: inode #15:
comm syz.0.17: corrupted extent tree: lblk 0 < prev 66
Investigation revealed that the inode has both flags set: DEBUG: inode 15 - flag=1, i_inline_off=164, has_inline=1, extents_flag=1
This is an invalid combination since an inode should have either: - INLINE_DATA: data stored directly in the inode - EXTENTS: data stored in extent-mapped blocks
Having both flags causes ext4_has_inline_data() to return true, skipping extent tree validation in __ext4_iget(). The unvalidated out-of-order extents then trigger a BUG_ON in ext4_es_cache_extent() due to integer underflow when calculating hole sizes.
Fix this by detecting this invalid flag combination early in ext4_iget() and rejecting the corrupted inode.
{
"affected": [],
"aliases": [
"CVE-2025-40167"
],
"database_specific": {
"cwe_ids": [],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2025-11-12T11:15:47Z",
"severity": null
},
"details": "In the Linux kernel, the following vulnerability has been resolved:\n\next4: detect invalid INLINE_DATA + EXTENTS flag combination\n\nsyzbot reported a BUG_ON in ext4_es_cache_extent() when opening a verity\nfile on a corrupted ext4 filesystem mounted without a journal.\n\nThe issue is that the filesystem has an inode with both the INLINE_DATA\nand EXTENTS flags set:\n\n EXT4-fs error (device loop0): ext4_cache_extents:545: inode #15:\n comm syz.0.17: corrupted extent tree: lblk 0 \u003c prev 66\n\nInvestigation revealed that the inode has both flags set:\n DEBUG: inode 15 - flag=1, i_inline_off=164, has_inline=1, extents_flag=1\n\nThis is an invalid combination since an inode should have either:\n- INLINE_DATA: data stored directly in the inode\n- EXTENTS: data stored in extent-mapped blocks\n\nHaving both flags causes ext4_has_inline_data() to return true, skipping\nextent tree validation in __ext4_iget(). The unvalidated out-of-order\nextents then trigger a BUG_ON in ext4_es_cache_extent() due to integer\nunderflow when calculating hole sizes.\n\nFix this by detecting this invalid flag combination early in ext4_iget()\nand rejecting the corrupted inode.",
"id": "GHSA-x383-8hmc-j634",
"modified": "2025-11-12T12:30:28Z",
"published": "2025-11-12T12:30:28Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2025-40167"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/1437c95ab2a28b138d4521653583729f61ccb48b"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/1d3ad183943b38eec2acf72a0ae98e635dc8456b"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/1f5ccd22ff482639133f2a0fe08f6d19d0e68717"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/2e9e10657b04152ed0d6ecae8d0c02a3405e28f5"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/4954d297c91d292630ab43ba4d195dc371ce65d3"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/cb6039b68efa547b676a8a10fc4618d9d1865c23"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/de985264eef64be8a90595908f2e6a87946dad34"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/f061f7c331fc16250fc82aa68964f35821687217"
}
],
"schema_version": "1.4.0",
"severity": []
}
Sightings
| Author | Source | Type | Date |
|---|
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