CVE-2024-26590: erofs: fix inconsistent per-file compression format

Severity: medium (CVSS 5.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2024-02-22 · updated 2026-06-17
Weakness: CWE-476

Description

In the Linux kernel, the following vulnerability has been resolved: erofs: fix inconsistent per-file compression format EROFS can select compression algorithms on a per-file basis, and each per-file compression algorithm needs to be marked in the on-disk superblock for initialization. However, syzkaller can generate inconsistent crafted images that use an unsupported algorithmtype for specific inodes, e.g. use MicroLZMA algorithmtype even it's not set in `sbi->available_compr_algs`. This can lead to an unexpected "BUG: kernel NULL pointer dereference" if the corresponding decompressor isn't built-in. Fix this by checking against `sbi->available_compr_algs` for each m_algorithmformat request. Incorrect !erofs_sb_has_compr_cfgs preset bitmap is now fixed together since it was harmless previously.

Affected products

Linux kernel: from 5.16.0 before 6.6.14; from 6.7.0 before 6.7.2 — fixed in 6.6.14, 6.7.2

How to fix

Upgrade to a fixed version: Linux kernel 6.6.14, 6.7.2. Check the vendor advisory for mitigations.

References

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