CVE-2022-49348: Linux Kernel

Medium severity, CVSS 5.5. EPSS: 0.3% chance of exploitation in the next 30 days.

In the Linux kernel, the following vulnerability has been resolved: ext4: filter out EXT4_FC_REPLAY from on-disk superblock field s_state The EXT4_FC_REPLAY bit in sbi->s_mount_state is used to indicate that we are in the middle of replay the fast commit journal. This was actually a mistake, since the sbi->s_mount_info is initialized from es->s_state. Arguably s_mount_state is misleadingly named, but the name is historical --- s_mount_state and s_state dates back to ext2. What should have been used is the ext4_{set,clear,test}_mount_flag() inline functions, which sets EXT4_MF_* bits in sbi->s_mount_flags. The problem with using EXT4_FC_REPLAY is that a maliciously corrupted superblock could result in EXT4_FC_REPLAY getting set in s_mount_state. This bypasses some sanity checks, and this can trigger a BUG() in ext4_es_cache_extent(). As a easy-to-backport-fix, filter out the EXT4_FC_REPLAY bit for now. We should eventually transition away from EXT4_FC_REPLAY to something like EXT4_MF_REPLAY.

Affected products

• Linux Linux Kernel: from 5.10, before 5.10.121 (fixed in 5.10.121); from 5.11, before 5.15.46 (fixed in 5.15.46); from 5.16, before 5.17.14 (fixed in 5.17.14); from 5.18, before 5.18.3 (fixed in 5.18.3)

Published 2025-02-26. Last modified 2026-06-17.