| From bippy-5f407fcff5a0 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-2025-21795: NFSD: fix hang in nfsd4_shutdown_callback |
| |
| Description |
| =========== |
| |
| In the Linux kernel, the following vulnerability has been resolved: |
| |
| NFSD: fix hang in nfsd4_shutdown_callback |
| |
| If nfs4_client is in courtesy state then there is no point to send |
| the callback. This causes nfsd4_shutdown_callback to hang since |
| cl_cb_inflight is not 0. This hang lasts about 15 minutes until TCP |
| notifies NFSD that the connection was dropped. |
| |
| This patch modifies nfsd4_run_cb_work to skip the RPC call if |
| nfs4_client is in courtesy state. |
| |
| The Linux kernel CVE team has assigned CVE-2025-21795 to this issue. |
| |
| |
| Affected and fixed versions |
| =========================== |
| |
| Issue introduced in 5.10.220 with commit 67ef9e5fd737eab2495f2586df7e9ea30caa1b77 and fixed in 5.10.235 with commit abed68027ea3ab893ac85cc46a00e2e64a324239 |
| Issue introduced in 5.15.154 with commit 26540b8940a2e21582afa61a6fb8af87310bac72 and fixed in 5.15.179 with commit efa8a261c575f816c7e79a87aeb3ef8a0bd6b221 |
| Issue introduced in 5.19 with commit 66af25799940b26efd41ea6e648f75c41a48a2c2 and fixed in 6.1.129 with commit 38d345f612503b850c2973e5a879f88e441b34d7 |
| Issue introduced in 5.19 with commit 66af25799940b26efd41ea6e648f75c41a48a2c2 and fixed in 6.6.79 with commit 23ad7797c74cd8f7f90617f1e59a8703e2b43908 |
| Issue introduced in 5.19 with commit 66af25799940b26efd41ea6e648f75c41a48a2c2 and fixed in 6.12.16 with commit cedfbb92cf97a6bff3d25633001d9c44442ee854 |
| Issue introduced in 5.19 with commit 66af25799940b26efd41ea6e648f75c41a48a2c2 and fixed in 6.13.4 with commit e88d2451cd42e025465d6b51fd716a47b0b3800d |
| Issue introduced in 5.19 with commit 66af25799940b26efd41ea6e648f75c41a48a2c2 and fixed in 6.14 with commit 036ac2778f7b28885814c6fbc07e156ad1624d03 |
| |
| 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-2025-21795 |
| 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/nfsd/nfs4callback.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/abed68027ea3ab893ac85cc46a00e2e64a324239 |
| https://git.kernel.org/stable/c/efa8a261c575f816c7e79a87aeb3ef8a0bd6b221 |
| https://git.kernel.org/stable/c/38d345f612503b850c2973e5a879f88e441b34d7 |
| https://git.kernel.org/stable/c/23ad7797c74cd8f7f90617f1e59a8703e2b43908 |
| https://git.kernel.org/stable/c/cedfbb92cf97a6bff3d25633001d9c44442ee854 |
| https://git.kernel.org/stable/c/e88d2451cd42e025465d6b51fd716a47b0b3800d |
| https://git.kernel.org/stable/c/036ac2778f7b28885814c6fbc07e156ad1624d03 |
