Description
In the Linux kernel, the following vulnerability has been resolved:
nfsd: check that server is running in unlock_filesystem
If we are trying to unlock the filesystem via an administrative
interface and nfsd isn't running, it crashes the server. This
happens currently because nfsd4_revoke_states() access state
structures (eg., conf_id_hashtbl) that has been freed as a part
of the server shutdown.
[ 59.465072] Call trace:
[ 59.465308] nfsd4_revoke_states+0x1b4/0x898 [nfsd] (P)
[ 59.465830] write_unlock_fs+0x258/0x440 [nfsd]
[ 59.466278] nfsctl_transaction_write+0xb0/0x120 [nfsd]
[ 59.466780] vfs_write+0x1f0/0x938
[ 59.467088] ksys_write+0xfc/0x1f8
[ 59.467395] __arm64_sys_write+0x74/0xb8
[ 59.467746] invoke_syscall.constprop.0+0xdc/0x1e8
[ 59.468177] do_el0_svc+0x154/0x1d8
[ 59.468489] el0_svc+0x40/0xe0
[ 59.468767] el0t_64_sync_handler+0xa0/0xe8
[ 59.469138] el0t_64_sync+0x1ac/0x1b0
Ensure this can't happen by taking the nfsd_mutex and checking that
the server is still up, and then holding the mutex across the call to
nfsd4_revoke_states().
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| Linux | Linux | 6.9 | 6.12.66 |
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | linux | 6.18.8-1 | — |
| Debian 13 | linux | 6.12.69-1 | DSA-6126-1 |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 25.10 | linux +8 | No fix yet | — |
| Ubuntu 24.04 LTS | linux-azure-6.17 | 6.17.0-1021.21~24.04.1 | USN-8604-1 |
| Ubuntu 24.04 LTS | linux-azure-fde-6.17 | 6.17.0-1018.18~24.04.1 | USN-8605-1 |
| Ubuntu 24.04 LTS | linux-gcp-6.17 | 6.17.0-1021.24~24.04.1 | USN-8570-1 |
| Ubuntu 24.04 LTS | linux-hwe-6.17 | 6.17.0-41.41~24.04.1 | — |
| Ubuntu 24.04 LTS | linux-nvidia-6.17 | 6.17.0-1031.31 | USN-8669-1 |
| Ubuntu 24.04 LTS | linux-oem-6.17 | 6.17.0-1030.30 | USN-8594-1 |
| Ubuntu 24.04 LTS | linux-oracle-6.17 | 6.17.0-1019.19~24.04.3 | USN-8570-2 |
| Ubuntu 24.04 LTS | linux-riscv +20 | No fix yet | — |
| Ubuntu 22.04 LTS | linux-riscv +32 | No fix yet | — |
| Ubuntu 20.04 LTS | linux-gke +28 | No fix yet | — |
| Ubuntu 18.04 LTS | linux-gcp +14 | No fix yet | — |
Show 2 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 16.04 LTS | linux-hwe-edge | No fix yet | — |
| Ubuntu Pro Realtime 24.04 LTS | linux-realtime-6.14 | No fix yet | — |
| Ubuntu Pro Realtime 24.04 LTS | linux-realtime-6.17 | 6.17.0-1018.20~24.04.1 | USN-8570-1 |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 15 SP7 | kernel-64kb +7 | 6.4.0-150700.53.34.1 | SUSE-SU-2026:1081-1 |
| SLES 15 SP7 | kernel-default-base | 6.4.0-150700.53.34.1.150700.17.23.1 | SUSE-SU-2026:1081-1 |
Show 5 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES for SAP 16.0 | kernel-64kb +8 | 6.12.0-160000.26.1 | SUSE-SU-2026:20599-1 |
| SLES for SAP 16.0 | kernel-default-base | 6.12.0-160000.26.1.160000.2.7 | SUSE-SU-2026:20599-1 |
| SLES 16.0 | kernel-64kb +8 | 6.12.0-160000.26.1 | SUSE-SU-2026:20615-1, SUSE-SU-2026:20599-1 |
| SLES 16.0 | kernel-default-base | 6.12.0-160000.26.1.160000.2.7 | SUSE-SU-2026:20599-1 |
| SLE Micro 6.2 | kernel-default-base | 6.12.0-160000.26.1.160000.2.7 | SUSE-SU-2026:20555-1 |
| SLE Micro 6.2 | kernel-rt +5 | 6.12.0-160000.26.1 | SUSE-SU-2026:20570-1, SUSE-SU-2026:20555-1 |
| SLE Live Patching 15 SP7 | kernel-default | 6.4.0-150700.53.34.1 | SUSE-SU-2026:1081-1 |
| SLE Live Patching 15 SP7 | kernel-livepatch-SLE15-SP7-RT_Update_10 | 1-150700.1.3.1 | SUSE-SU-2026:0962-1 |
| SLE Live Patching 15 SP7 | kernel-livepatch-SLE15-SP7_Update_10 | 1-150700.15.3.1 | SUSE-SU-2026:1081-1 |
| SUSE Real Time Module 15 SP7 | kernel-rt +2 | 6.4.0-150700.7.34.1 | SUSE-SU-2026:0962-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Leap 16.0 | kernel-default-base | 6.12.0-160000.26.1.160000.2.7 | openSUSE-SU-2026:20287-1 |
| openSUSE Leap 16.0 | kernel-rt +11 | 6.12.0-160000.26.1 | openSUSE-SU-2026:20287-1 |
Amazon Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Amazon Linux 2023 | kernel-livepatch-6.12.66-88.122 | 1:1.0-0.amzn2023 | ALAS2023-2026-1488 |
| Amazon Linux 2023 | perf6.12 +14 | 1:6.12.66-88.122.amzn2023 | ALAS2023-2026-1488 |
Oracle Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Oracle Linux 9 | kernel-uek +34 | 6.12.0-109.67.6.el10uek | ELSA-2026-50144 |
| Oracle Linux 8 | bpftool +18 | 5.15.0-320.202.8.2.el9uek | ELSA-2026-50261 |
Advisories 18
- WID-SEC-2026-0215 Linux Kernel: Mehrere Schwachstellen BSI CERT-Bund (WID) · Nov 12, 2026
- USN-8604-1 linux-azure-6.17 vulnerabilities Ubuntu Security Notices (USN) · Nov 7, 2026
- USN-8669-1 linux-nvidia-6.17 vulnerabilities Ubuntu Security Notices (USN) · Nov 6, 2026
- USN-8570-1 linux-gcp-6.17, linux-realtime-6.17 vulnerabilities Ubuntu Security Notices (USN) · Nov 6, 2026
- USN-8570-2 linux-oracle-6.17 vulnerabilities Ubuntu Security Notices (USN) · Nov 6, 2026
- USN-8594-1 linux-oem-6.17 vulnerabilities Ubuntu Security Notices (USN) · Nov 6, 2026
- USN-8605-1 linux-azure-fde-6.17 vulnerabilities Ubuntu Security Notices (USN) · Oct 17, 2026
- SUSE-SU-2026:20570-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Jul 9, 2026
- ELSA-2026-50261 Important: Unbreakable Enterprise kernel security update (Oracle Linux 8) Oracle Linux Security Advisories (ELSA) · May 10, 2026
- ALAS2023-2026-1488 Important: kernel6.12 security update (Amazon Linux 2023) Amazon Linux Security Center (ALAS) · Mar 27, 2026
- SUSE-SU-2026:1081-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Mar 27, 2026
- SUSE-SU-2026:0962-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Mar 24, 2026
- openSUSE-SU-2026:20287-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Mar 23, 2026
- SUSE-SU-2026:20615-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Mar 23, 2026
- SUSE-SU-2026:20599-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Mar 23, 2026
- SUSE-SU-2026:20555-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Mar 23, 2026
- ELSA-2026-50144 Important: Unbreakable Enterprise kernel security update (Oracle Linux 9) Oracle Linux Security Advisories (ELSA) · Mar 10, 2026
- DSA-6126-1 linux - security update Debian Security (DSA / DLA) · Mar 9, 2026