Description
In the Linux kernel, the following vulnerability has been resolved:
x86/fpu: Ensure XFD state on signal delivery
Sean reported [1] the following splat when running KVM tests:
WARNING: CPU: 232 PID: 15391 at xfd_validate_state+0x65/0x70
Call Trace:
<TASK>
fpu__clear_user_states+0x9c/0x100
arch_do_signal_or_restart+0x142/0x210
exit_to_user_mode_loop+0x55/0x100
do_syscall_64+0x205/0x2c0
entry_SYSCALL_64_after_hwframe+0x4b/0x53
Chao further identified [2] a reproducible scenario involving signal
delivery: a non-AMX task is preempted by an AMX-enabled task which
modifies the XFD MSR.
When the non-AMX task resumes and reloads XSTATE with init values,
a warning is triggered due to a mismatch between fpstate::xfd and the
CPU's current XFD state. fpu__clear_user_states() does not currently
re-synchronize the XFD state after such preemption.
Invoke xfd_update_state() which detects and corrects the mismatch if
there is a dynamic feature.
This also benefits the sigreturn path, as fpu__restore_sig() may call
fpu__clear_user_states() when the sigframe is inaccessible.
[ dhansen: minor changelog munging ]
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| Linux | Linux | 5.16 | 6.1.159 |
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 | 6.17.8-1 | — |
| Debian 13 | linux | 6.12.63-1 | — |
| Debian 12 | linux | 6.1.159-1 | — |
| Debian 11 | linux-6.1 | 6.1.159-1~deb11u1 | DLA-4436-1 |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu Nvidia-BlueField 24.04 LTS | linux-bluefield | 6.8.0-1017.21 | — |
| Ubuntu Nvidia-BlueField 22.04 LTS | linux-bluefield | No fix yet | — |
| Ubuntu 25.10 | linux | 6.17.0-14.14 | USN-8029-1 |
| Ubuntu 25.10 | linux-aws +2 | 6.17.0-1007.7 | USN-8030-1, USN-8029-2 |
| Ubuntu 25.10 | linux-azure +1 | 6.17.0-1008.8 | USN-8029-3, USN-8029-1 |
| Ubuntu 25.10 | linux-azure-fde | No fix yet | — |
| Ubuntu 25.10 | linux-realtime | 6.17.0-1006.7 | USN-8029-1 |
| Ubuntu 25.10 | linux-riscv | 6.17.0-14.14.1 | — |
| Ubuntu 24.04 LTS | linux | 6.8.0-106.106 | USN-8095-1 |
| Ubuntu 24.04 LTS | linux-aws | 6.8.0-1050.53 | USN-8095-1 |
| Ubuntu 24.04 LTS | linux-aws-6.17 +1 | 6.17.0-1007.7~24.04.1 | — |
| Ubuntu 24.04 LTS | linux-azure | 6.8.0-1051.57 | USN-8125-1 |
| Ubuntu 24.04 LTS | linux-azure-fde | 6.8.0-1058.65 | — |
| Ubuntu 24.04 LTS | linux-azure-nvidia | 6.8.0-1039.42 | — |
| Ubuntu 24.04 LTS | linux-gcp | 6.8.0-1052.55 | USN-8095-1 |
| Ubuntu 24.04 LTS | linux-gcp-6.17 | 6.17.0-1008.8~24.04.1 | — |
| Ubuntu 24.04 LTS | linux-gke | 6.8.0-1048.53 | USN-8095-1 |
| Ubuntu 24.04 LTS | linux-gkeop | 6.8.0-1035.38 | USN-8095-1 |
| Ubuntu 24.04 LTS | linux-ibm | 6.8.0-1049.49 | USN-8095-1 |
| Ubuntu 24.04 LTS | linux-lowlatency | 6.8.0-106.106.1 | USN-8095-1 |
| Ubuntu 24.04 LTS | linux-nvidia | 6.8.0-1049.52 | USN-8100-1 |
| Ubuntu 24.04 LTS | linux-nvidia-6.17 | 6.17.0-1008.8 | — |
| Ubuntu 24.04 LTS | linux-nvidia-lowlatency | 6.8.0-1049.52.1 | USN-8100-1 |
| Ubuntu 24.04 LTS | linux-nvidia-tegra | 6.8.0-1020.20 | — |
| Ubuntu 24.04 LTS | linux-oem-6.17 | 6.17.0-1011.11 | USN-8048-1 |
| Ubuntu 24.04 LTS | linux-oracle | 6.8.0-1047.48 | USN-8095-1 |
| Ubuntu 24.04 LTS | linux-raspi | 6.8.0-1050.54 | USN-8095-5 |
| Ubuntu 24.04 LTS | linux-riscv +18 | No fix yet | — |
| Ubuntu 24.04 LTS | linux-xilinx | 6.8.0-1028.29 | USN-8261-1 |
| Ubuntu 22.04 LTS | linux +49 | No fix yet | — |
| Ubuntu 22.04 LTS | linux-aws-6.8 | 6.8.0-1050.53~22.04.1 | USN-8095-4 |
| Ubuntu 22.04 LTS | linux-azure-6.8 | 6.8.0-1051.57~22.04.1 | USN-8126-1 |
| Ubuntu 22.04 LTS | linux-azure-fde-6.8 | 6.8.0-1058.65~22.04.1 | — |
| Ubuntu 22.04 LTS | linux-gcp-6.8 | 6.8.0-1052.55~22.04.1 | USN-8095-1 |
| Ubuntu 22.04 LTS | linux-hwe-6.8 +1 | 6.8.0-106.106~22.04.1 | USN-8095-1 |
| Ubuntu 22.04 LTS | linux-ibm-6.8 | 6.8.0-1049.49~22.04.1 | USN-8095-1 |
| Ubuntu 22.04 LTS | linux-lowlatency-hwe-6.8 | 6.8.0-106.106.1~22.04.1 | USN-8095-1 |
| Ubuntu 22.04 LTS | linux-nvidia-6.8 | 6.8.0-1049.52~22.04.1 | USN-8100-1 |
| Ubuntu 22.04 LTS | linux-oracle-6.8 | 6.8.0-1047.48~22.04.1 | USN-8095-1 |
Show 9 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-raspi-realtime | 6.8.0-2040.41 | USN-8095-5 |
| Ubuntu Pro Realtime 24.04 LTS | linux-realtime | 6.8.1-1045.46 | USN-8095-3 |
| Ubuntu Pro Realtime 24.04 LTS | linux-realtime-6.14 | No fix yet | — |
| Ubuntu Pro Realtime 24.04 LTS | linux-realtime-6.17 | 6.17.0-1006.7~24.04.1 | — |
| Ubuntu Pro Realtime 22.04 LTS | linux-realtime +1 | No fix yet | — |
| Ubuntu Pro Realtime 22.04 LTS | linux-realtime-6.8 | 6.8.1-1045.46~22.04.1 | USN-8095-3 |
| Ubuntu Pro FIPS-updates 24.04 LTS | linux-aws-fips | 6.8.0-1050.53+fips1 | USN-8095-2 |
| Ubuntu Pro FIPS-updates 24.04 LTS | linux-azure-fips | 6.8.0-1052.58+fips1 | USN-8165-1 |
| Ubuntu Pro FIPS-updates 24.04 LTS | linux-fips | 6.8.0-106.106+fips1 | USN-8095-2 |
| Ubuntu Pro FIPS-updates 24.04 LTS | linux-gcp-fips | 6.8.0-1052.55+fips1 | USN-8095-2 |
| Ubuntu Pro FIPS-updates 22.04 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-aws-5.15 +10 | No fix yet | — |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 15 SP7 | kernel-64kb +6 | 6.4.0-150700.53.31.1 | SUSE-SU-2026:0447-1 |
| SLES 15 SP7 | kernel-azure +2 | 6.4.0-150700.20.27.1 | SUSE-SU-2026:0472-1 |
| SLES 15 SP7 | kernel-default-base | 6.4.0-150700.53.31.1.150700.17.21.1 | SUSE-SU-2026:0447-1 |
Show 7 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES for SAP 16.0 | kernel-64kb +8 | 6.12.0-160000.9.1 | SUSE-SU-2026:20220-1 |
| SLES for SAP 16.0 | kernel-default-base | 6.12.0-160000.9.1.160000.2.6 | SUSE-SU-2026:20220-1 |
| SLES 16.0 | kernel-64kb +8 | 6.12.0-160000.9.1 | SUSE-SU-2026:20228-1, SUSE-SU-2026:20220-1 |
| SLES 16.0 | kernel-default-base | 6.12.0-160000.9.1.160000.2.6 | SUSE-SU-2026:20220-1 |
| SLE Micro 6.2 | kernel-default-base | 6.12.0-160000.9.1.160000.2.6 | SUSE-SU-2026:20207-1 |
| SLE Micro 6.2 | kernel-rt +5 | 6.12.0-160000.9.1 | SUSE-SU-2026:20564-1, SUSE-SU-2026:20207-1 |
| SLE Micro 6.1 | kernel-default-base | 6.4.0-39.1.21.16 | SUSE-SU-2026:20498-1 |
| SLE Micro 6.1 | kernel-rt +1 | 6.4.0-40.1 | SUSE-SU-2026:20876-1 |
| SLE Micro 6.1 | kernel-source +2 | 6.4.0-39.1 | SUSE-SU-2026:20498-1 |
| SLE Micro 6.0 | kernel-default-base | 6.4.0-39.1.21.16 | SUSE-SU-2026:20477-1 |
| SLE Micro 6.0 | kernel-rt +1 | 6.4.0-40.1 | SUSE-SU-2026:20845-1 |
| SLE Micro 6.0 | kernel-source +2 | 6.4.0-39.1 | SUSE-SU-2026:20477-1 |
| SLE Live Patching 15 SP7 | kernel-default | 6.4.0-150700.53.31.1 | SUSE-SU-2026:0447-1 |
| SLE Live Patching 15 SP7 | kernel-livepatch-SLE15-SP7-RT_Update_9 | 1-150700.1.3.2 | SUSE-SU-2026:0587-1 |
| SLE Live Patching 15 SP7 | kernel-livepatch-SLE15-SP7_Update_9 | 1-150700.15.3.1 | SUSE-SU-2026:0447-1 |
| SUSE Real Time Module 15 SP7 | kernel-rt | 6.4.0-150700.7.31.2 | SUSE-SU-2026:0587-1 |
| SUSE Real Time Module 15 SP7 | kernel-syms-rt +1 | 6.4.0-150700.7.31.1 | SUSE-SU-2026:0587-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Leap 16.0 | kernel-default-base | 6.12.0-160000.9.1.160000.2.6 | openSUSE-SU-2026:20145-1 |
| openSUSE Leap 16.0 | kernel-rt +11 | 6.12.0-160000.9.1 | openSUSE-SU-2026:20145-1 |
Amazon Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Amazon Linux 2023 | kernel-livepatch-6.12.58-82.121 +1 | 1:1.0-0.amzn2023 | ALAS2023-2026-1495, ALAS2023-2025-1350 |
| Amazon Linux 2023 | perf +14 | 1:6.1.159-181.297.amzn2023 | ALAS2023-2025-1350 |
| Amazon Linux 2023 | perf6.12 +14 | 1:6.12.58-82.121.amzn2023 | ALAS2023-2026-1495 |
Oracle Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Oracle Linux 9 | kernel-uek +34 | 6.12.0-107.59.3.2.el10uek | ELSA-2026-50006 |
| Oracle Linux 8 | bpftool +18 | 5.15.0-320.202.8.2.el9uek | ELSA-2026-50261 |
Advisories 33
- WID-SEC-2025-2868 Linux Kernel: Mehrere Schwachstellen BSI CERT-Bund (WID) · Nov 12, 2026
- USN-8100-1 linux-nvidia, linux-nvidia-6.8, linux-nvidia-lowlatency vulnerabilities Ubuntu Security Notices (USN) · Nov 4, 2026
- USN-8165-1 linux-azure-fips vulnerabilities Ubuntu Security Notices (USN) · Nov 4, 2026
- USN-8095-1 linux, linux-aws, linux-gcp, linux-gcp-6.8, linux-gke, linux-gkeop, linux-hwe-6.8, linux-ibm, linux-ibm-6.8, linux-lowlatency, linux-lowlatency-hwe-6.8, linux-oracle, linux-oracle-6.8 vulnerabilities Ubuntu Security Notices (USN) · Nov 3, 2026
- USN-8095-2 linux-fips, linux-aws-fips, linux-gcp-fips vulnerabilities Ubuntu Security Notices (USN) · Nov 3, 2026
- USN-8126-1 linux-azure-6.8 vulnerabilities Ubuntu Security Notices (USN) · Nov 3, 2026
- USN-8095-5 linux-raspi, linux-raspi-realtime vulnerabilities Ubuntu Security Notices (USN) · Nov 3, 2026
- USN-8125-1 linux-azure vulnerabilities Ubuntu Security Notices (USN) · Nov 3, 2026
- USN-8095-4 linux-aws-6.8 vulnerabilities Ubuntu Security Notices (USN) · Nov 3, 2026
- USN-8029-2 linux-aws, linux-oracle vulnerabilities Ubuntu Security Notices (USN) · Nov 3, 2026
- USN-8048-1 linux-oem-6.17 vulnerabilities Ubuntu Security Notices (USN) · Nov 3, 2026
- USN-8029-3 linux-azure vulnerabilities Ubuntu Security Notices (USN) · Nov 3, 2026
- USN-8030-1 linux-gcp vulnerabilities Ubuntu Security Notices (USN) · Nov 3, 2026
- USN-8029-1 linux, linux-raspi, linux-realtime vulnerabilities Ubuntu Security Notices (USN) · Nov 3, 2026
- USN-8095-3 linux-realtime, linux-realtime-6.8 vulnerabilities Ubuntu Security Notices (USN) · Nov 3, 2026
- USN-8261-1 linux-xilinx vulnerabilities Ubuntu Security Notices (USN) · Sep 7, 2026
- SUSE-SU-2026:20564-1 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
- SUSE-SU-2026:20876-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Mar 31, 2026
- SUSE-SU-2026:20845-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Mar 28, 2026
- ALAS2023-2026-1495 Important: kernel6.12 security update (Amazon Linux 2023) Amazon Linux Security Center (ALAS) · Mar 27, 2026
- openSUSE-SU-2026:20145-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Mar 23, 2026
- SUSE-SU-2026:20498-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Mar 23, 2026
- SUSE-SU-2026:20477-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Mar 23, 2026
- SUSE-SU-2026:20228-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Mar 23, 2026
- SUSE-SU-2026:20207-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Mar 23, 2026
- SUSE-SU-2026:20220-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Mar 23, 2026
- SUSE-SU-2026:0587-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Mar 23, 2026
- SUSE-SU-2026:0472-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Mar 23, 2026
- SUSE-SU-2026:0447-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Mar 23, 2026
- ALAS2023-2025-1350 Important: kernel security update (Amazon Linux 2023) Amazon Linux Security Center (ALAS) · Feb 11, 2026
- DLA-4436-1 linux-6.1 - security update Debian Security (DSA / DLA) · Jan 14, 2026
- ELSA-2026-50006 Important: Unbreakable Enterprise kernel security update (Oracle Linux 9) Oracle Linux Security Advisories (ELSA) · Jan 13, 2026
References
- https://git.kernel.org/stable/c/eefbfb722042fc9210d2e0ac2b063fd1abf51895
- https://git.kernel.org/stable/c/1811c610653c0cd21cc9add14595b7cffaeca511
- https://git.kernel.org/stable/c/5b2619b488f1d08b960c43c6468dd0759e8b3035
- https://git.kernel.org/stable/c/3f735419c4b43cde42e6d408db39137b82474e31
- https://git.kernel.org/stable/c/388eff894d6bc5f921e9bfff0e4b0ab2684a96e9