ext4: convert inline data to extents when truncate exceeds inline size
Summary
| CVE | CVE-2026-31452 |
| State | PUBLISHED |
| Assigner | Linux |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-04-22 14:16:39 UTC |
| Updated | 2026-04-22 14:16:39 UTC |
| Description | In the Linux kernel, the following vulnerability has been resolved:
ext4: convert inline data to extents when truncate exceeds inline size
Add a check in ext4_setattr() to convert files from inline data storage
to extent-based storage when truncate() grows the file size beyond the
inline capacity. This prevents the filesystem from entering an
inconsistent state where the inline data flag is set but the file size
exceeds what can be stored inline.
Without this fix, the following sequence causes a kernel BUG_ON():
1. Mount filesystem with inode that has inline flag set and small size
2. truncate(file, 50MB) - grows size but inline flag remains set
3. sendfile() attempts to write data
4. ext4_write_inline_data() hits BUG_ON(write_size > inline_capacity)
The crash occurs because ext4_write_inline_data() expects inline storage
to accommodate the write, but the actual inline capacity (~60 bytes for
i_block + ~96 bytes for xattrs) is far smaller than the file size and
write request.
The fix checks if the new size from setattr exceeds the inode's actual
inline capacity (EXT4_I(inode)->i_inline_size) and converts the file to
extent-based storage before proceeding with the size change.
This addresses the root cause by ensuring the inline data flag and file
size remain consistent during truncate operations. |
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|
| CNA |
Linux |
Linux |
affected 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 110d7ef602659ce4d7947c5480f7ca2779696aaf git |
Not specified |
| CNA |
Linux |
Linux |
affected 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 f53a5d9f32924bc2a810d2df243b7714da58b636 git |
Not specified |
| CNA |
Linux |
Linux |
affected 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 c047332be7195833a5c5126816c2502df8269fe4 git |
Not specified |
| CNA |
Linux |
Linux |
affected 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 699bac4d4c951974d55b045c983d1de777215949 git |
Not specified |
| CNA |
Linux |
Linux |
affected 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 7920dcc571cef3d8aa9ee109c136125d61d41669 git |
Not specified |
| CNA |
Linux |
Linux |
affected 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 93cb2d103e5c707de0f7ad58a39b7f0fddc27aa6 git |
Not specified |
| CNA |
Linux |
Linux |
affected 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 07c1a31af18290054da3d18221b8bf58983c5d3a git |
Not specified |
| CNA |
Linux |
Linux |
affected 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 ed9356a30e59c7cc3198e7fc46cfedf3767b9b17 git |
Not specified |
| CNA |
Linux |
Linux |
unaffected 5.10.253 5.10.* semver |
Not specified |
| CNA |
Linux |
Linux |
unaffected 5.15.203 5.15.* semver |
Not specified |
| CNA |
Linux |
Linux |
unaffected 6.1.168 6.1.* semver |
Not specified |
| CNA |
Linux |
Linux |
unaffected 6.6.131 6.6.* semver |
Not specified |
| CNA |
Linux |
Linux |
unaffected 6.12.80 6.12.* semver |
Not specified |
| CNA |
Linux |
Linux |
unaffected 6.18.21 6.18.* semver |
Not specified |
| CNA |
Linux |
Linux |
unaffected 6.19.11 6.19.* semver |
Not specified |
| CNA |
Linux |
Linux |
unaffected 7.0 * original_commit_for_fix |
Not specified |
References
| Reference | Source | Link | Tags |
|---|
| git.kernel.org/stable/c/699bac4d4c951974d55b045c983d1de777215949 |
416baaa9-dc9f-4396-8d5f-8c081fb06d67 |
git.kernel.org |
|
| git.kernel.org/stable/c/110d7ef602659ce4d7947c5480f7ca2779696aaf |
416baaa9-dc9f-4396-8d5f-8c081fb06d67 |
git.kernel.org |
|
| git.kernel.org/stable/c/f53a5d9f32924bc2a810d2df243b7714da58b636 |
416baaa9-dc9f-4396-8d5f-8c081fb06d67 |
git.kernel.org |
|
| git.kernel.org/stable/c/93cb2d103e5c707de0f7ad58a39b7f0fddc27aa6 |
416baaa9-dc9f-4396-8d5f-8c081fb06d67 |
git.kernel.org |
|
| git.kernel.org/stable/c/07c1a31af18290054da3d18221b8bf58983c5d3a |
416baaa9-dc9f-4396-8d5f-8c081fb06d67 |
git.kernel.org |
|
| git.kernel.org/stable/c/ed9356a30e59c7cc3198e7fc46cfedf3767b9b17 |
416baaa9-dc9f-4396-8d5f-8c081fb06d67 |
git.kernel.org |
|
| git.kernel.org/stable/c/7920dcc571cef3d8aa9ee109c136125d61d41669 |
416baaa9-dc9f-4396-8d5f-8c081fb06d67 |
git.kernel.org |
|
| git.kernel.org/stable/c/c047332be7195833a5c5126816c2502df8269fe4 |
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.