Description
In the Linux kernel, the following vulnerability has been resolved:
NFSv4/flexfiles: fix NULL dereference for NFSv4.0 data servers
flexfiles accepts NFSv4.0 data servers, but two NFSv4 code paths assume
the data server client has a session. Unlike NFSv4.1+, an NFSv4.0 client
has no session (clp->cl_session is NULL; it uses clp->cl_slot_tbl), so
I/O to a v4.0 flexfiles DS oopses:
- nfs4_init_ds_session() dereferences clp->cl_session->session_state
while seeding the DS lease. It also only seeds cl_lease_time when
NFS4_SESSION_INITING is set; without a session that never happens, so
cl_lease_time stays 0 and nfs4_renew_state() busy-loops, requeuing
every 5 seconds. Seed the lease whenever there is no session and
return before touching session state.
- ff_layout_async_handle_error_v4() dereferences
clp->cl_session->fc_slot_table on every DS I/O error. Fall back to the
v4.0 transport slot table (clp->cl_slot_tbl) when there is no session.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| Linux | Linux | 4.12 | 6.1.191 |
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 | 7.2.6-1 | — |
| Debian 13 | linux | 6.12.115-2 | — |
| Debian 12 | linux | No fix yet | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu Nvidia-BlueField 24.04 LTS | linux-bluefield | No fix yet | — |
| Ubuntu Nvidia-BlueField 22.04 LTS | linux-bluefield | No fix yet | — |
| Ubuntu 26.04 LTS | linux | 7.0.0-42.42 | USN-8959-1 |
| Ubuntu 26.04 LTS | linux-aws | 7.0.0-1016.17 | USN-8959-1 |
| Ubuntu 26.04 LTS | linux-azure | 7.0.0-1020.21 | USN-9019-1 |
| Ubuntu 26.04 LTS | linux-azure-fde | 7.0.0-1019.19 | USN-9020-1 |
| Ubuntu 26.04 LTS | linux-gcp | 7.0.0-1016.18 | USN-8959-1 |
| Ubuntu 26.04 LTS | linux-gke | 7.0.0-1010.11 | USN-9020-1 |
| Ubuntu 26.04 LTS | linux-ibm +1 | 7.0.0-1017.17 | USN-8960-1, USN-8959-1 |
| Ubuntu 26.04 LTS | linux-nvidia +1 | No fix yet | — |
| Ubuntu 26.04 LTS | linux-oracle | 7.0.0-1015.16 | USN-8959-1 |
| Ubuntu 26.04 LTS | linux-raspi | 7.0.0-1023.23 | USN-9021-1 |
| Ubuntu 26.04 LTS | linux-realtime | 7.0.0-43.43.1 | USN-9020-1 |
| Ubuntu 26.04 LTS | linux-riscv | 7.0.0-42.42.1 | — |
| Ubuntu 24.04 LTS | linux +46 | No fix yet | — |
| Ubuntu 24.04 LTS | linux-aws-7.0 | 7.0.0-1017.18~24.04.1 | USN-9020-1 |
| Ubuntu 24.04 LTS | linux-azure-fde-7.0 | 7.0.0-1019.19~24.04.1 | USN-9020-1 |
| Ubuntu 24.04 LTS | linux-gcp-7.0 | 7.0.0-1017.19~24.04.1 | USN-9020-1 |
| Ubuntu 24.04 LTS | linux-hwe-7.0 | 7.0.0-42.42~24.04.1 | USN-8959-1 |
| Ubuntu 24.04 LTS | linux-oracle-7.0 | 7.0.0-1016.18~24.04.1 | USN-9020-1 |
| Ubuntu 24.04 LTS | linux-riscv-7.0 | 7.0.0-42.42.1~24.04.1 | — |
| Ubuntu 22.04 LTS | linux +59 | No fix yet | — |
Show 16 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 20.04 LTS | linux-gke +28 | No fix yet | — |
| Ubuntu 18.04 LTS | linux-gcp +14 | No fix yet | — |
| Ubuntu 16.04 LTS | linux-hwe-edge | No fix yet | — |
| Ubuntu Pro Realtime 24.04 LTS | linux-realtime +3 | No fix yet | — |
| Ubuntu Pro Realtime 22.04 LTS | linux-realtime +2 | No fix yet | — |
| Ubuntu Pro FIPS 20.04 LTS | linux-fips +3 | No fix yet | — |
| Ubuntu Pro FIPS 18.04 LTS | linux-fips +3 | No fix yet | — |
| Ubuntu Pro FIPS-updates 24.04 LTS | linux-fips +3 | No fix yet | — |
| Ubuntu Pro FIPS-updates 22.04 LTS | linux-fips +3 | No fix yet | — |
| Ubuntu Pro FIPS-updates 20.04 LTS | linux-fips +3 | No fix yet | — |
| Ubuntu Pro FIPS-updates 18.04 LTS | linux-fips +3 | No fix yet | — |
| Ubuntu Pro FIPS-preview 22.04 LTS | linux-fips +3 | No fix yet | — |
| Ubuntu Pro 20.04 LTS | linux +21 | No fix yet | — |
| Ubuntu Pro 18.04 LTS | linux +12 | No fix yet | — |
| Ubuntu Pro 16.04 LTS | linux-gcp +4 | No fix yet | — |
| Ubuntu Pro 14.04 LTS | linux-azure | No fix yet | — |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 15 SP7 | kernel-64kb +7 | 6.4.0-150700.53.84.1 | SUSE-SU-2026:4706-1 |
| SLES 15 SP7 | kernel-default-base | 6.4.0-150700.53.84.1.150700.17.47.1 | SUSE-SU-2026:4706-1 |
| SLES 12 SP5 | kernel-syms +2 | 4.12.14-122.333.2 | SUSE-SU-2026:4687-1 |
Show 8 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES for SAP 16.0 | kernel-64kb +8 | 6.12.0-160000.39.1 | SUSE-SU-2026:24235-1 |
| SLES for SAP 16.0 | kernel-default-base | 6.12.0-160000.39.1.160000.2.26 | SUSE-SU-2026:24235-1 |
| SLES 16.0 | kernel-64kb +8 | 6.12.0-160000.39.1 | SUSE-SU-2026:24235-1, SUSE-SU-2026:24197-1 |
| SLES 16.0 | kernel-default-base | 6.12.0-160000.39.1.160000.2.26 | SUSE-SU-2026:24235-1 |
| SLE Micro 6.2 | kernel-default-base | 6.12.0-160000.39.1.160000.2.26 | SUSE-SU-2026:24184-1 |
| SLE Micro 6.2 | kernel-rt +5 | 6.12.0-160000.39.1 | SUSE-SU-2026:24184-1, SUSE-SU-2026:24179-1 |
| SLE Micro 6.2 | podman | 5.4.2-160000.6.1 | SUSE-SU-2026:24182-1 |
| SLE Micro 6.1 | kernel-default-base | 6.4.0-159998.53.1.159998.21.38 | SUSE-SU-2026:24181-1 |
| SLE Micro 6.1 | kernel-rt +4 | 6.4.0-159998.53.1 | SUSE-SU-2026:24182-1, SUSE-SU-2026:24181-1 |
| SLE Micro 6.0 | kernel-default-base | 6.4.0-159998.53.1.159998.21.38 | SUSE-SU-2026:24315-1 |
| SLE Micro 6.0 | kernel-rt +4 | 6.4.0-159998.53.1 | SUSE-SU-2026:24316-1, SUSE-SU-2026:24315-1 |
| SLE Live Patching 15 SP7 | kernel-default | 6.4.0-150700.53.84.1 | SUSE-SU-2026:4706-1 |
| SLE Live Patching 15 SP7 | kernel-livepatch-SLE15-SP7-RT_Update_21 | 1-150700.1.3.1 | SUSE-SU-2026:4640-1 |
| SLE Live Patching 15 SP7 | kernel-livepatch-SLE15-SP7_Update_22 | 1-150700.15.3.1 | SUSE-SU-2026:4706-1 |
| SLE Live Patching 12 SP5 | kernel-default | 4.12.14-122.333.2 | SUSE-SU-2026:4687-1 |
| SLE Live Patching 12 SP5 | kgraft-patch-SLE12-SP5_Update_88 | 1-8.3.3 | SUSE-SU-2026:4687-1 |
| SUSE Real Time Module 15 SP7 | kernel-rt +2 | 6.4.0-150700.7.78.1 | SUSE-SU-2026:4640-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | kernel-source | 7.2.8-1.1 | openSUSE-SU-2026:11893-1 |
| openSUSE Leap 16.0 | kernel-default-base | 6.12.0-160000.39.1.160000.2.25 | openSUSE-SU-2026:22091-1 |
| openSUSE Leap 16.0 | kernel-rt +11 | 6.12.0-160000.39.1 | openSUSE-SU-2026:22091-1 |
Amazon Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Amazon Linux 2023 | kernel-livepatch-6.18.54-121.166 +1 | 1:1.0-0.amzn2023 | ALAS2023-2026-3402, ALAS2023-2026-3192 |
| Amazon Linux 2023 | perf6.12 +11 | 1:6.12.114-139.210.amzn2023 | ALAS2023-2026-3402 |
| Amazon Linux 2023 | perf6.18 +12 | 1:6.18.54-121.166.amzn2023 | ALAS2023-2026-3192 |
Azure Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Azure Linux 3 | kernel | 6.6.161.1-1 | — |
Advisories 21
- USN-9021-1 linux-raspi vulnerabilities Ubuntu Security Notices (USN) · Nov 12, 2026
- WID-SEC-2026-3444 Linux Kernel: Mehrere Schwachstellen BSI CERT-Bund (WID) · Nov 12, 2026
- USN-9020-1 linux-aws-7.0, linux-azure-fde, linux-azure-fde-7.0, linux-gcp-7.0, linux-gke, linux-oracle-7.0, linux-realtime vulnerabilities Ubuntu Security Notices (USN) · Nov 12, 2026
- USN-8959-1 linux, linux-aws, linux-gcp, linux-hwe-7.0, linux-ibm, linux-oracle vulnerabilities Ubuntu Security Notices (USN) · Nov 12, 2026
- USN-9019-1 linux-azure vulnerabilities Ubuntu Security Notices (USN) · Nov 12, 2026
- USN-8960-1 linux-oem-7.0 vulnerabilities Ubuntu Security Notices (USN) · Nov 12, 2026
- ALAS2023-2026-3402 Important: kernel6.12 security update (Amazon Linux 2023) Amazon Linux Security Center (ALAS) · Nov 11, 2026
- SUSE-SU-2026:24315-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Oct 27, 2026
- SUSE-SU-2026:24316-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Oct 27, 2026
- ALAS2023-2026-3192 Important: kernel6.18 security update (Amazon Linux 2023) Amazon Linux Security Center (ALAS) · Oct 26, 2026
- SUSE-SU-2026:24235-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Oct 21, 2026
- SUSE-SU-2026:24197-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Oct 21, 2026
- SUSE-SU-2026:24184-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Oct 20, 2026
- SUSE-SU-2026:24179-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Oct 20, 2026
- SUSE-SU-2026:24181-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Oct 20, 2026
- SUSE-SU-2026:24182-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Oct 20, 2026
- openSUSE-SU-2026:22091-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Oct 19, 2026
- SUSE-SU-2026:4706-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Oct 17, 2026
- SUSE-SU-2026:4687-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Oct 16, 2026
- SUSE-SU-2026:4640-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Oct 14, 2026
- openSUSE-SU-2026:11893-1 kernel-devel-7.2.8-1.1 on GA media SUSE / openSUSE Security Updates · Sep 29, 2026
References
- https://git.kernel.org/stable/c/e55d7fec8a9290f73032ee34c35dd68532809633
- https://git.kernel.org/stable/c/336b6da10021c69a8f273bbacdf7432fdc89a06f
- https://git.kernel.org/stable/c/5527af72b0100c94287bfec901b6313eeac567ca
- https://git.kernel.org/stable/c/163c16e01f53fc8eb8d0f3484ae6c382265ecbbd
- https://git.kernel.org/stable/c/436a214514e24103159aea455147d58b44a8a585
- https://git.kernel.org/stable/c/2b03ebbf8d5e8f6af4ecd6c65375232dd1ec32cc