CyberRota Analysis
AI-GeneratedThe vulnerability affects the btrfs filesystem in the Linux kernel, specifically during the splitting of extent maps, where the EXTENT_FLAG_LOGGING is incorrectly propagated to new split maps. This can lead to a use-after-free condition when the extent map is freed while still on the inode's modified_extents list, potentially causing system instability or crashes. System administrators and developers managing Linux environments with btrfs should prioritize this issue to mitigate risks associated with data corruption and system reliability.
Original NVD Description
In the Linux kernel, the following vulnerability has been resolved: btrfs: don't propagate EXTENT_FLAG_LOGGING to split extent maps When btrfs_drop_extent_map_range() splits an extent map, the new split maps inherit the original map's flags through a local 'flags' variable. Commit f86f7a75e2fb ("btrfs: use the flags of an extent map to identify the compression type") changed the EXTENT_FLAG_LOGGING clearing to operate on em->flags instead of that local 'flags' copy, so a split of an extent map that is currently being logged wrongly inherits EXTENT_FLAG_LOGGING. The flag is then never cleared on the split, and when it is freed while still on the inode's modified_extents list (for example by the extent map shrinker) it trips the WARN_ON(!list_empty(&em->list)) in btrfs_free_extent_map() and leads to a use-after-free. Clear EXTENT_FLAG_LOGGING from the local 'flags' copy used for the splits and only clear EXTENT_FLAG_PINNED from em->flags, restoring the behaviour prior to f86f7a75e2fb.