Race Condition in F2FS File System in Linux Kernel

CVE-2025-40150

What is CVE-2025-40150?

A race condition vulnerability was identified in the F2FS file system of the Linux kernel. When the fallocate function operates on a pinning file, it may inadvertently race with the block allocation process. This scenario can lead to migrations of segments that have just been allocated, resulting in inconsistencies between the on-disk SSA and the in-memory state, ultimately causing the filesystem to shut down. The issue arises from segment type mismatches when garbage collection interacts with live logging activities. To mitigate this, checks have been implemented to ensure that garbage collection does not operate on an empty section and additional sanity checks are enforced during the garbage collection process.

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