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.

References

• https://nvd.nist.gov/vuln/detail/CVE-2024-26590
• https://git.kernel.org/stable/c/118a8cf504d7dfa519562d000f423ee3ca75d2c4
• https://git.kernel.org/stable/c/823ba1d2106019ddf195287ba53057aee33cf724
• https://git.kernel.org/stable/c/eed24b816e50c6cd18cbee0ff0d7218c8fced199
• https://git.kernel.org/stable/c/47467e04816cb297905c0f09bc2d11ef865942d9