CVE-2025-21900

Summary

CVE-2025-21900 is a vulnerability affecting the Linux kernel's NFSv4 file system. If a file with the name "sillyrenamed" is identified for deletion during a server reboot, it can lead to a race condition where the application call to close() clashes with an open reclaim operation. This can trigger a deadlock when put_nfs_open_context() makes a synchronous delegreturn call, which is not marked as privileged. To mitigate this issue, the call to nfs4_inode_return_delegation_on_close() has been updated to catch the delegreturn and schedule it asynchronously.

Prevent cyber attacks with Recorded Future by prioritizing and patching critical vulnerabilities being exploited by threat actors targeting your industry. Book your demo to learn more.