CVE-2025-68794

iomap: adjust read range correctly for non-block-aligned positions

State: Published
Severity: 9.8 Critical
Published: Jan 13, 2026
Updated: Oct 19, 2026
Reserved: Dec 24, 2025

Description

In the Linux kernel, the following vulnerability has been resolved:

iomap: adjust read range correctly for non-block-aligned positions

iomap_adjust_read_range() assumes that the position and length passed in are block-aligned. This is not always the case however, as shown in the syzbot generated case for erofs. This causes too many bytes to be skipped for uptodate blocks, which results in returning the incorrect position and length to read in. If all the blocks are uptodate, this underflows length and returns a position beyond the folio.

Fix the calculation to also take into account the block offset when calculating how many bytes can be skipped for uptodate blocks.

Scores

CVSS	Score	Vector	Source
3.1	9.8 Critical	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H	Linux

Weaknesses

CWE-190 Integer Overflow or Wraparound

Affected Products

Product	Versions
LinuxLinux	9dc55f1389f9569acf9659e58dd836a9c70df217 to before ce20f49ac9194cf81a77f01d1c316d7c17ae753cAffected 9dc55f1389f9569acf9659e58dd836a9c70df217 to before 275b37a1e5c2c8abd313e8075f6aec9a349f291bAffected 9dc55f1389f9569acf9659e58dd836a9c70df217 to before b8c9f25fd84328c5fcc4f70c6d1e8f1d4787eaacAffected 9dc55f1389f9569acf9659e58dd836a9c70df217 to before 82b60ffbb532d919959702768dca04c3c0500ae5Affected 9dc55f1389f9569acf9659e58dd836a9c70df217 to before 12053695c8ef5410e8cc6c9ed4c0db9cd9c82b3eAffected 9dc55f1389f9569acf9659e58dd836a9c70df217 to before 142194fb21afe964d2d194cab1fc357cbf87e899Affected 9dc55f1389f9569acf9659e58dd836a9c70df217 to before 7aa6bc3e8766990824f66ca76c19596ce10daf3eAffected
LinuxLinux	4.19Affected before 4.19Not affected 5.10.267 through 5.10.Not affected 5.15.218 through 5.15.Not affected 6.1.185 through 6.1.Not affected 6.6.120 through 6.6.Not affected 6.12.64 through 6.12.Not affected 6.18.3 through 6.18.Not affected 6.19 and laterNot affected

Product

Versions

LinuxLinux

9dc55f1389f9569acf9659e58dd836a9c70df217 to before ce20f49ac9194cf81a77f01d1c316d7c17ae753cAffected
9dc55f1389f9569acf9659e58dd836a9c70df217 to before 275b37a1e5c2c8abd313e8075f6aec9a349f291bAffected
9dc55f1389f9569acf9659e58dd836a9c70df217 to before b8c9f25fd84328c5fcc4f70c6d1e8f1d4787eaacAffected
9dc55f1389f9569acf9659e58dd836a9c70df217 to before 82b60ffbb532d919959702768dca04c3c0500ae5Affected
9dc55f1389f9569acf9659e58dd836a9c70df217 to before 12053695c8ef5410e8cc6c9ed4c0db9cd9c82b3eAffected
9dc55f1389f9569acf9659e58dd836a9c70df217 to before 142194fb21afe964d2d194cab1fc357cbf87e899Affected
9dc55f1389f9569acf9659e58dd836a9c70df217 to before 7aa6bc3e8766990824f66ca76c19596ce10daf3eAffected

LinuxLinux

4.19Affected
before 4.19Not affected
5.10.267 through 5.10.*Not affected
5.15.218 through 5.15.*Not affected
6.1.185 through 6.1.*Not affected
6.6.120 through 6.6.*Not affected
6.12.64 through 6.12.*Not affected
6.18.3 through 6.18.*Not affected
6.19 and laterNot affected

References

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