CVE-2025-40150

Name of the Vulnerable Software and Affected Versions Linux kernel (affected versions not specified)

Description The Linux kernel contains a flaw within the f2fs filesystem related to segment migration. A race condition can occur during file allocation and garbage collection, specifically when a pinning file undergoes fallocate operations concurrently with block allocation. This can lead to inconsistencies between segment types in on-disk structures (SSA) and in-memory structures (SIT), potentially causing filesystem shutdown. The issue arises from fallocate potentially racing with block allocation, resulting in garbage collection migrating a segment that has just been allocated by a log. The inconsistency occurs when the on-disk SSA indicates a segment type that differs from the in-memory SIT. The fix involves checking for empty sections before garbage collection and adding sanity checks to do garbage collect() to prevent race conditions during segment migration. The functions involved include f2fs expand inode data, f2fs allocate pinning section, f2fs gc range, do garbage collect, f2fs allocate data block, and new curseg.

Recommendations At the moment, there is no information about a newer version that contains a fix for this vulnerability.