CVE-2026-31452

Advisory lineage Upstream: 0 Downstream: 15
Analyzed
Published: 22 Apr 2026, 13:53
Last modified:14 Jul 2026, 12:47

Vulnerability Summary

Overall Risk (default)
medium
31/100
CVSS Score
7.8 HIGH
v3.1 (nvd)
EPSS Score
0.13% LOW
0% probability 0.00%
KEV
Not listed
Ransomware
No reports
Public exploits
None found
Dark Web
Not detected

Timeline

22 Apr 2026, 13:53
Published
Vulnerability first disclosed
14 Jul 2026, 12:47
Last Modified
Vulnerability information updated

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.

CVSS Metrics

  • v3.1•HIGH•Score: 7.8CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

EPSS Trends

Current EPSS score: 0.13%• Percentile: 3%

Techniques & Countermeasures

  • CWE-787•Out-of-bounds Write

    The product writes data past the end, or before the beginning, of the intended buffer.

Affected Systems

  • linux•linux

    ≥ 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, < 110d7ef602659ce4d7947c5480f7ca2779696aaf | ≥ 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, < f53a5d9f32924bc2a810d2df243b7714da58b636 | ≥ 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, < c047332be7195833a5c5126816c2502df8269fe4 | ≥ 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, < 699bac4d4c951974d55b045c983d1de777215949 | ≥ 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, < 7920dcc571cef3d8aa9ee109c136125d61d41669 | ≥ 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, < 93cb2d103e5c707de0f7ad58a39b7f0fddc27aa6 | ≥ 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, < 07c1a31af18290054da3d18221b8bf58983c5d3a | ≥ 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, < ed9356a30e59c7cc3198e7fc46cfedf3767b9b17 | ≥ 67cf5b09a46f72e048501b84996f2f77bc42e947, < 110d7ef602659ce4d7947c5480f7ca2779696aaf | ≥ 67cf5b09a46f72e048501b84996f2f77bc42e947, < f53a5d9f32924bc2a810d2df243b7714da58b636 | ≥ 67cf5b09a46f72e048501b84996f2f77bc42e947, < c047332be7195833a5c5126816c2502df8269fe4 | ≥ 67cf5b09a46f72e048501b84996f2f77bc42e947, < 699bac4d4c951974d55b045c983d1de777215949 | ≥ 67cf5b09a46f72e048501b84996f2f77bc42e947, < 7920dcc571cef3d8aa9ee109c136125d61d41669 | ≥ 67cf5b09a46f72e048501b84996f2f77bc42e947, < 93cb2d103e5c707de0f7ad58a39b7f0fddc27aa6 | ≥ 67cf5b09a46f72e048501b84996f2f77bc42e947, < 07c1a31af18290054da3d18221b8bf58983c5d3a | ≥ 67cf5b09a46f72e048501b84996f2f77bc42e947, < ed9356a30e59c7cc3198e7fc46cfedf3767b9b17 | 3.8

  • linux•linux kernel

    ≥ 3.8, < 5.10.253 | ≥ 5.11, < 5.15.203 | ≥ 5.16, < 6.1.168 | ≥ 6.2, < 6.6.131 | ≥ 6.7, < 6.12.80 | ≥ 6.13, < 6.18.21 | ≥ 6.19, < 6.19.11 | 7.0:rc1 | 7.0:rc2 | 7.0:rc3 | 7.0:rc4 | 7.0:rc5

References (10)