Race Condition Vulnerability in Linux Kernel NFSv4/pNFS Products

CVE-2025-38393

What is CVE-2025-38393?

A race condition vulnerability in the Linux kernel's NFSv4/pNFS implementation can lead to system hangs during writeback processes. This issue arises when multiple systems contend for the same page lock, resulting in one task waiting indefinitely on the NFS_LAYOUT_DRAIN bit in pnfs_update_layout(). In this scenario, the outstanding count of pnfs_layout_hdr remains zero, indicating potential synchronization failures. The vulnerability was addressed by applying a recommended barrier to enhance task synchronization and prevent such race conditions from occurring.

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