| From bippy-7c5fe7eed585 Mon Sep 17 00:00:00 2001 |
| From: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| To: <linux-cve-announce@vger.kernel.org> |
| Reply-to: <cve@kernel.org>, <linux-kernel@vger.kernel.org> |
| Subject: CVE-2025-21900: NFSv4: Fix a deadlock when recovering state on a sillyrenamed file |
| |
| Description |
| =========== |
| |
| 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. |
| |
| The Linux kernel CVE team has assigned CVE-2025-21900 to this issue. |
| |
| |
| Affected and fixed versions |
| =========================== |
| |
| Issue introduced in 6.11 with commit adb4b42d19aea91826621a8d0bac94cf2c08f8bc and fixed in 6.12.18 with commit 4fe4ae6c2e01d028856b73b6328b12b8945df871 |
| Issue introduced in 6.11 with commit adb4b42d19aea91826621a8d0bac94cf2c08f8bc and fixed in 6.13.6 with commit f41a60bc43e7abbc636fee78bed0d74c31e738b0 |
| Issue introduced in 6.11 with commit adb4b42d19aea91826621a8d0bac94cf2c08f8bc and fixed in 6.14 with commit 8f8df955f078e1a023ee55161935000a67651f38 |
| |
| Please see https://www.kernel.org for a full list of currently supported |
| kernel versions by the kernel community. |
| |
| Unaffected versions might change over time as fixes are backported to |
| older supported kernel versions. The official CVE entry at |
| https://cve.org/CVERecord/?id=CVE-2025-21900 |
| will be updated if fixes are backported, please check that for the most |
| up to date information about this issue. |
| |
| |
| Affected files |
| ============== |
| |
| The file(s) affected by this issue are: |
| fs/nfs/delegation.c |
| fs/nfs/delegation.h |
| fs/nfs/nfs4proc.c |
| |
| |
| Mitigation |
| ========== |
| |
| The Linux kernel CVE team recommends that you update to the latest |
| stable kernel version for this, and many other bugfixes. Individual |
| changes are never tested alone, but rather are part of a larger kernel |
| release. Cherry-picking individual commits is not recommended or |
| supported by the Linux kernel community at all. If however, updating to |
| the latest release is impossible, the individual changes to resolve this |
| issue can be found at these commits: |
| https://git.kernel.org/stable/c/4fe4ae6c2e01d028856b73b6328b12b8945df871 |
| https://git.kernel.org/stable/c/f41a60bc43e7abbc636fee78bed0d74c31e738b0 |
| https://git.kernel.org/stable/c/8f8df955f078e1a023ee55161935000a67651f38 |
