UBUNTU-CVE-2025-21900
In the Linux kernel, the following vulnerability has been resolved: NFSv4: Fix a deadlock when recovering state on a sillyrenamed file If the file is sillyrenamed, and slated for delete on close, it is possible for a server reboot to triggeer an open reclaim, with can again race with the application call to close(). When that happens, the call to put_nfs_open_context() can trigger a synchronous delegreturn call which deadlocks because it is not marked as privileged. Instead, ensure that the call to nfs4_inode_return_delegation_on_close() catches the delegreturn, and schedules it asynchronously.
02 / AFFECTED SOFTWARE
Affected packages
11 explicit affected versions
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35 explicit affected versions
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1 explicit affected versions
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37 explicit affected versions
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26 explicit affected versions
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3 explicit affected versions
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51 explicit affected versions
13 explicit affected versions
12 explicit affected versions
27 explicit affected versions
8 explicit affected versions
5 explicit affected versions
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13 explicit affected versions
7 explicit affected versions
3 explicit affected versions
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12 explicit affected versions
44 explicit affected versions
16 explicit affected versions
3 explicit affected versions
13 explicit affected versions
26 explicit affected versions
45 explicit affected versions
37 explicit affected versions
14 explicit affected versions
38 explicit affected versions
9 explicit affected versions
11 explicit affected versions
7 explicit affected versions
4 explicit affected versions
1 explicit affected versions
13 explicit affected versions
43 explicit affected versions
10 explicit affected versions
8 explicit affected versions
14 explicit affected versions
4 explicit affected versions
78 explicit affected versions
11 explicit affected versions
1 explicit affected versions
03 / CONNECTIONS
Connected vulnerabilities
04 / EVIDENCE
Source records
In the Linux kernel, the following vulnerability has been resolved: NFSv4: Fix a deadlock when recovering state on a sillyrenamed file If the file is sillyrenamed, and slated for delete on close, it is possible for a server reboot to triggeer an open reclaim, with can again race with the application call to close(). When that happens, the call to put_nfs_open_context() can trigger a synchronous delegreturn call which deadlocks because it is not marked as privileged. Instead, ensure that the call to nfs4_inode_return_delegation_on_close() catches the delegreturn, and schedules it asynchronously.
05 / REFERENCES
Further evidence
- https://git.kernel.org/linus/8f8df955f078e1a023ee55161935000a67651f38
- https://git.kernel.org/stable/c/4fe4ae6c2e01d028856b73b6328b12b8945df871
- https://git.kernel.org/stable/c/8f8df955f078e1a023ee55161935000a67651f38
- https://git.kernel.org/stable/c/f41a60bc43e7abbc636fee78bed0d74c31e738b0
- https://ubuntu.com/security/CVE-2025-21900
- https://ubuntu.com/security/notices/USN-7521-1
- https://ubuntu.com/security/notices/USN-7521-2
- https://ubuntu.com/security/notices/USN-7521-3
- https://www.cve.org/CVERecord?id=CVE-2025-21900