Description
In the Linux kernel, the following vulnerability has been resolved:
perf/x86/amd/core: Avoid enabling BRS from the SVM reload path
Branch Sampling (BRS) and Last Branch Record (LBR) are mutually
exclusive hardware features, and users of both are tracked via
cpuc->lbr_users.
When SVM is toggled on a CPU, the host perf events are reprogrammed to
update the HostOnly filter bit (set when virtualization is enabled,
cleared when it is disabled). On PerfMonV2-capable processors, this
reprogramming is performed by calling amd_pmu_enable_all() to rewrite
the event selectors. However, amd_pmu_enable_all() also calls
amd_brs_enable_all(), which enables BRS whenever cpuc->lbr_users > 0.
Having active LBR events satisfies this gating on processors that have
LBR but not BRS. The kernel then tries to set the BRS enable bit in
DebugExtnCfg (MSR 0xc000010f). Since that bit is deprecated on such
hardware, the write results in a #GP:
Call Trace:
<IRQ>
amd_pmu_enable_all+0x1d/0x90
amd_pmu_disable_virt+0x62/0xb0
kvm_arch_disable_virtualization_cpu+0xa/0x40 [kvm]
hardware_disable_nolock+0x1a/0x30 [kvm]
__flush_smp_call_function_queue+0x9b/0x410
__sysvec_call_function+0x18/0xc0
sysvec_call_function+0x69/0x90
</IRQ>
<TASK>
asm_sysvec_call_function+0x16/0x20
RIP: 0010:cpuidle_enter_state+0xc4/0x450
? cpuidle_enter_state+0xb7/0x450
cpuidle_enter+0x29/0x40
cpuidle_idle_call+0xf5/0x160
do_idle+0x7b/0xe0
cpu_startup_entry+0x26/0x30
start_secondary+0x115/0x140
secondary_startup_64_no_verify+0x194/0x19b
</TASK>
Fix this by ensuring that BRS is not enabled from the event selector
reprogramming path even when cpuc->lbr_users > 0.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| Linux | Linux | 5.19 | 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 | 7.1.5-1 | — |
| Debian 13 | linux | 6.12.100-1 | — |
| Debian 12 | linux | No fix yet | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu Nvidia-BlueField 24.04 LTS | linux-bluefield | 6.8.0-1033.38 | — |
| Ubuntu 26.04 LTS | linux | 7.0.0-38.38 | USN-8887-1 |
| Ubuntu 26.04 LTS | linux-aws +1 | 7.0.0-1014.14 | USN-8887-1 |
| Ubuntu 26.04 LTS | linux-azure | 7.0.0-1017.17 | USN-8888-1 |
| Ubuntu 26.04 LTS | linux-azure-fde | 7.0.0-1016.16 | USN-8888-1 |
| Ubuntu 26.04 LTS | linux-gke | 7.0.0-1008.9 | USN-8887-1 |
| Ubuntu 26.04 LTS | linux-ibm +1 | 7.0.0-1015.15 | USN-8889-1, USN-8887-1 |
| Ubuntu 26.04 LTS | linux-nvidia | 7.0.0-1025.26 | USN-9043-1 |
| Ubuntu 26.04 LTS | linux-nvidia-bos | 7.0.0-2022.23 | USN-9003-1 |
| Ubuntu 26.04 LTS | linux-oracle | 7.0.0-1013.13 | USN-8887-1 |
| Ubuntu 26.04 LTS | linux-raspi | 7.0.0-1023.23 | USN-9021-1 |
| Ubuntu 26.04 LTS | linux-riscv +1 | 7.0.0-38.38.1 | USN-8887-1 |
| Ubuntu 24.04 LTS | linux | 6.8.0-147.147 | USN-8917-1 |
| Ubuntu 24.04 LTS | linux-aws +1 | 6.8.0-1067.70 | USN-9024-1, USN-8917-1 |
| Ubuntu 24.04 LTS | linux-aws-7.0 +1 | 7.0.0-1014.14~24.04.1 | USN-8887-3, USN-8887-2 |
| Ubuntu 24.04 LTS | linux-azure-7.0 | 7.0.0-1017.17~24.04.1 | USN-8888-2 |
| Ubuntu 24.04 LTS | linux-azure-fde | 6.8.0-1069.76 | USN-8918-1 |
| Ubuntu 24.04 LTS | linux-azure-fde-7.0 | 7.0.0-1016.16~24.04.1 | USN-8888-2 |
| Ubuntu 24.04 LTS | linux-gcp +1 | 6.8.0-1071.79 | USN-8918-1, USN-8917-1 |
| Ubuntu 24.04 LTS | linux-gke | 6.8.0-1066.74 | USN-8917-1 |
| Ubuntu 24.04 LTS | linux-gkeop | 6.8.0-1052.56 | USN-8917-1 |
| Ubuntu 24.04 LTS | linux-hwe-7.0 | 7.0.0-38.38~24.04.4 | USN-8887-3 |
| Ubuntu 24.04 LTS | linux-ibm | 6.8.0-1067.68 | USN-8917-1 |
| Ubuntu 24.04 LTS | linux-lowlatency | 6.8.0-147.147.1 | USN-8917-1 |
| Ubuntu 24.04 LTS | linux-nvidia-7.0 | 7.0.0-1024.25~24.04.1 | USN-9003-1 |
| Ubuntu 24.04 LTS | linux-nvidia-lowlatency | 6.8.0-1067.70.1 | USN-9040-1 |
| Ubuntu 24.04 LTS | linux-nvidia-tegra | 6.8.0-1039.40 | USN-9091-1 |
| Ubuntu 24.04 LTS | linux-oracle | 6.8.0-1064.67 | USN-8917-1 |
| Ubuntu 24.04 LTS | linux-oracle-7.0 | 7.0.0-1013.13~24.04.1 | USN-8887-3 |
| Ubuntu 24.04 LTS | linux-raspi | 6.8.0-1068.72 | USN-9025-1 |
| Ubuntu 24.04 LTS | linux-riscv +29 | No fix yet | — |
| Ubuntu 24.04 LTS | linux-riscv-7.0 | 7.0.0-38.38.1~24.04.1 | — |
| Ubuntu 24.04 LTS | linux-vmware | 6.8.0-1008.8 | — |
| Ubuntu 22.04 LTS | linux-aws-6.8 | 6.8.0-1069.74~22.04.1 | USN-9024-1 |
| Ubuntu 22.04 LTS | linux-azure-6.8 | 6.8.0-1073.82~22.04.1 | USN-9026-1 |
| Ubuntu 22.04 LTS | linux-azure-fde-6.8 | 6.8.0-1071.78~22.04.1 | USN-9026-1 |
| Ubuntu 22.04 LTS | linux-gcp-6.8 | 6.8.0-1073.81~22.04.1 | USN-9024-1 |
| Ubuntu 22.04 LTS | linux-hwe-6.8 | 6.8.0-149.149~22.04.1 | USN-9066-1 |
| Ubuntu 22.04 LTS | linux-ibm-6.8 | 6.8.0-1069.70~22.04.1 | USN-9024-1 |
| Ubuntu 22.04 LTS | linux-lowlatency-hwe-6.8 | 6.8.0-149.149.1~22.04.1 | USN-9024-1 |
| Ubuntu 22.04 LTS | linux-oracle-6.8 | 6.8.0-1067.71~22.04.1 | USN-9025-1 |
| Ubuntu 22.04 LTS | linux-riscv +33 | No fix yet | — |
| Ubuntu 20.04 LTS | linux-gke +28 | No fix yet | — |
Show 5 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| 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 | 6.8.0-2056.58 | USN-9025-1 |
| Ubuntu Pro Realtime 24.04 LTS | linux-realtime | 6.8.1-1062.63 | USN-8917-1 |
| Ubuntu Pro Realtime 24.04 LTS | linux-realtime-6.14 +1 | No fix yet | — |
| Ubuntu Pro Realtime 22.04 LTS | linux-realtime-6.8 | 6.8.1-1064.65~22.04.1 | USN-9024-1 |
| Ubuntu Pro FIPS-updates 24.04 LTS | linux-aws-fips | 6.8.0-1067.70+fips1 | USN-8917-1 |
| Ubuntu Pro FIPS-updates 24.04 LTS | linux-fips | 6.8.0-147.147+fips1 | USN-8917-1 |
| Ubuntu Pro FIPS-updates 24.04 LTS | linux-gcp-fips +1 | 6.8.0-1071.79+fips1 | USN-8918-1, USN-8917-1 |
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 |
Show 7 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES for SAP 16.0 | kernel-64kb +8 | 6.12.0-160000.38.1 | SUSE-SU-2026:23902-1 |
| SLES for SAP 16.0 | kernel-default-base | 6.12.0-160000.38.1.160000.2.23 | SUSE-SU-2026:23902-1 |
| SLES 16.0 | kernel-64kb +8 | 6.12.0-160000.38.1 | SUSE-SU-2026:23902-1, SUSE-SU-2026:23897-1 |
| SLES 16.0 | kernel-default-base | 6.12.0-160000.38.1.160000.2.23 | SUSE-SU-2026:23902-1 |
| SLE Micro 6.2 | kernel-default-base | 6.12.0-160000.38.1.160000.2.23 | SUSE-SU-2026:23887-1 |
| SLE Micro 6.2 | kernel-rt +5 | 6.12.0-160000.38.1 | SUSE-SU-2026:23887-1, SUSE-SU-2026:23881-1 |
| 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 |
| 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 Leap 16.0 | kernel-default-base | 6.12.0-160000.38.1.160000.2.22 | openSUSE-SU-2026:21910-1 |
| openSUSE Leap 16.0 | kernel-rt +11 | 6.12.0-160000.38.1 | openSUSE-SU-2026:21910-1 |
Amazon Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Amazon Linux 2023 | kernel-livepatch-6.18.41-94.142 +1 | 1:1.0-0.amzn2023 | ALAS2023-2026-2071, ALAS2023-2026-2057 |
| Amazon Linux 2023 | perf6.12 +11 | 1:6.12.100-125.179.amzn2023 | ALAS2023-2026-2057 |
| Amazon Linux 2023 | perf6.18 +12 | 1:6.18.41-94.142.amzn2023 | ALAS2023-2026-2071 |
Azure Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Azure Linux 3 | kernel | 6.6.161.1-1 | — |
Oracle Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Oracle Linux 9 | kernel-uek +34 | 6.12.0-206.104.3.3.el10uek | ELSA-2026-500248 |
Advisories 32
- USN-9091-1 linux-nvidia-tegra vulnerabilities Ubuntu Security Notices (USN) · Nov 13, 2026
- USN-8917-1 linux, linux-aws, linux-aws-fips, linux-fips, linux-gcp, linux-gcp-fips, linux-gke, linux-gkeop, linux-ibm, linux-lowlatency, linux-oracle, linux-realtime vulnerabilities Ubuntu Security Notices (USN) · Nov 13, 2026
- USN-9025-1 linux-oracle-6.8, linux-raspi, linux-raspi-realtime vulnerabilities Ubuntu Security Notices (USN) · Nov 13, 2026
- USN-9024-1 linux-aws-6.8, linux-gcp-6.8, linux-ibm-6.8, linux-lowlatency-hwe-6.8, linux-nvidia, linux-realtime-6.8 vulnerabilities Ubuntu Security Notices (USN) · Nov 13, 2026
- USN-8887-1 linux, linux-aws, linux-gcp, linux-gke, linux-ibm, linux-oracle, linux-realtime vulnerabilities Ubuntu Security Notices (USN) · Nov 13, 2026
- USN-9026-1 linux-azure-6.8, linux-azure-fde-6.8 vulnerabilities Ubuntu Security Notices (USN) · Nov 13, 2026
- USN-9021-1 linux-raspi vulnerabilities Ubuntu Security Notices (USN) · Nov 13, 2026
- USN-9040-1 linux-nvidia-lowlatency vulnerabilities Ubuntu Security Notices (USN) · Nov 13, 2026
- USN-9066-1 linux-hwe-6.8 vulnerabilities Ubuntu Security Notices (USN) · Nov 13, 2026
- USN-8918-1 linux-azure, linux-azure-fde, linux-azure-fips vulnerabilities Ubuntu Security Notices (USN) · Nov 13, 2026
- USN-8888-2 linux-azure-7.0, linux-azure-fde-7.0 vulnerabilities Ubuntu Security Notices (USN) · Nov 13, 2026
- USN-9003-1 linux-nvidia-7.0, linux-nvidia-bos vulnerabilities Ubuntu Security Notices (USN) · Nov 13, 2026
- USN-8889-1 linux-oem-7.0 vulnerabilities Ubuntu Security Notices (USN) · Nov 13, 2026
- USN-8887-3 linux-gcp-7.0, linux-hwe-7.0, linux-oracle-7.0 vulnerabilities Ubuntu Security Notices (USN) · Nov 13, 2026
- USN-9043-1 linux-nvidia vulnerabilities Ubuntu Security Notices (USN) · Nov 13, 2026
- USN-8888-1 linux-azure, linux-azure-fde vulnerabilities Ubuntu Security Notices (USN) · Nov 13, 2026
- USN-8887-2 linux-aws-7.0 vulnerabilities Ubuntu Security Notices (USN) · Nov 13, 2026
- WID-SEC-2026-2852 Linux Kernel: Mehrere Schwachstellen BSI CERT-Bund (WID) · Nov 12, 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
- 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
- SUSE-SU-2026:4706-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Oct 17, 2026
- SUSE-SU-2026:4640-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Oct 14, 2026
- SUSE-SU-2026:23902-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Sep 30, 2026
- SUSE-SU-2026:23881-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Sep 30, 2026
- SUSE-SU-2026:23887-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Sep 30, 2026
- SUSE-SU-2026:23897-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Sep 30, 2026
- openSUSE-SU-2026:21910-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Sep 25, 2026
- ALAS2023-2026-2071 Important: kernel6.18 security update (Amazon Linux 2023) Amazon Linux Security Center (ALAS) · Sep 15, 2026
- ALAS2023-2026-2057 Important: kernel6.12 security update (Amazon Linux 2023) Amazon Linux Security Center (ALAS) · Sep 9, 2026
- ELSA-2026-500248 Important: Unbreakable Enterprise kernel security update (Oracle Linux 9) Oracle Linux Security Advisories (ELSA) · Sep 4, 2026
References
- https://git.kernel.org/stable/c/cb5322d04694d153cd5418267f8765a44b935f82
- https://git.kernel.org/stable/c/3b0aa139ba09a5b73c0f300e652076232f869f68
- https://git.kernel.org/stable/c/e9b1a7411a667539c2f55e720bbb5f623b526a32
- https://git.kernel.org/stable/c/7cc438c99bba324a0562b1bafa747b10f7e251df
- https://git.kernel.org/stable/c/46d0fd8535edce31f15e48d2de1bdee39a4850e5
- https://git.kernel.org/stable/c/07c60dda9c059c09f83d42a3ebda2e7cc1cf3bc2