ocfs2: validate directory-index entry counts when reading metadata
Summary
| CVE | CVE-2026-89492 |
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| State | PUBLISHED |
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| Assigner | Linux |
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| Source Priority | CVE Program / NVD first with legacy fallback |
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| Published | 2026-09-11 20:19:31 UTC |
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| Updated | 2026-09-11 20:19:31 UTC |
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| Description | In the Linux kernel, the following vulnerability has been resolved:
ocfs2: validate directory-index entry counts when reading metadata
ocfs2_validate_dx_leaf() and ocfs2_validate_dx_root() check the ECC and
signature of an indexed-directory block before it reaches higher-level
callers, but neither validator bounds the ocfs2_dx_entry_list counts
against the capacity of the block that holds them.
ocfs2_dx_dir_search() then walks
for (i = 0; i < le16_to_cpu(entry_list->de_num_used); i++)
dx_entry = &entry_list->de_entries[i];
over de_num_used entries with no bounds check. entry_list is either
dx_leaf->dl_list (from ocfs2_read_dx_leaf) or, for an inline root,
dx_root->dr_entries. A crafted on-disk image can set de_num_used (and
de_count, which is the __counted_by_le() bound of de_entries) to 0xffff
and make the walk read far past the end of the 4KB metadata block, giving
a slab out-of-bounds read reachable from any path lookup, stat() or open()
on an indexed directory once the image is mounted.
Commit 775c17386a6f ("ocfs2: validate dx_root extent list fields during
block read") already bounds dr_list for the non-inline dx_root, but left
the inline dr_entries path and the dx_leaf dl_list unchecked. Add the
same read-time validation for both entry lists: de_count must equal the
capacity of the block (ocfs2_dx_entries_per_leaf()/per_root()) and
de_num_used must not exceed de_count, rejecting corrupted metadata with
-EFSCORRUPTED before ocfs2_dx_dir_search() can walk an out-of-range entry
array.
de_count is always written as exactly the block capacity when a leaf or
inline root is formatted, so the equality check does not reject any valid
image.
Found by 0sec automated security-research tooling (https://0sec.ai). |
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Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
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| CNA |
Linux |
Linux |
affected 9b7895efac906d66d19856194e1ba61f37e231a4 fcfcba8fe17dbf2c8805690b8cc25e32d81249a4 git |
Not specified |
| CNA |
Linux |
Linux |
affected 9b7895efac906d66d19856194e1ba61f37e231a4 b8a5c0c32df2c5b685ceef76ac77e37c7e1dc3ed git |
Not specified |
| CNA |
Linux |
Linux |
affected 9b7895efac906d66d19856194e1ba61f37e231a4 bc70726ddad53c7e9a9a85915bf2415b0d4f42f9 git |
Not specified |
| CNA |
Linux |
Linux |
affected 2.6.30 |
Not specified |
| CNA |
Linux |
Linux |
unaffected 2.6.30 semver |
Not specified |
| CNA |
Linux |
Linux |
unaffected 6.18.51 6.18.* semver |
Not specified |
| CNA |
Linux |
Linux |
unaffected 7.2.4 7.2.* semver |
Not specified |
| CNA |
Linux |
Linux |
unaffected 7.3-rc1 * original_commit_for_fix |
Not specified |
References
| Reference | Source | Link | Tags |
|---|
| git.kernel.org/stable/c/fcfcba8fe17dbf2c8805690b8cc25e32d81249a4 |
416baaa9-dc9f-4396-8d5f-8c081fb06d67 |
git.kernel.org |
|
| git.kernel.org/stable/c/b8a5c0c32df2c5b685ceef76ac77e37c7e1dc3ed |
416baaa9-dc9f-4396-8d5f-8c081fb06d67 |
git.kernel.org |
|
| git.kernel.org/stable/c/bc70726ddad53c7e9a9a85915bf2415b0d4f42f9 |
416baaa9-dc9f-4396-8d5f-8c081fb06d67 |
git.kernel.org |
|
| CVE Program record |
CVE.ORG |
www.cve.org |
canonical |
| NVD vulnerability detail |
NVD |
nvd.nist.gov |
canonical, analysis |
No vendor comments have been submitted for this CVE.
There are currently no legacy QID mappings associated with this CVE.