UBUNTU-CVE-2024-50275: Low severity ubuntu/linux-hwe-edge vulnerability

Q: Which systems are realistically exposed to this issue?

The issue affects Arm64 systems using SVE, where SVE traps are enabled. The listed Ubuntu kernel packages are linux-realtime, linux-azure, linux-gcp, linux-gke, linux-gkeop, linux-riscv, linux-fips, and linux-azure-fde.

Q: What access and conditions does exploitation require?

The vector is local and requires low privileges. Exploitation depends on a preemption race during SVE trap handling, including the trap handler being preempted while it manipulates saved FPSIMD/SVE state.

Q: How can administrators identify a possible occurrence?

A possible symptom is an intermittent kernel warning from do_sve_acc() indicating that SVE access trapped unexpectedly while TIF_SVE was already set. The reported warning is "SVE access shouldn't have trapped".

Published Nov 19, 2024

Updated

In the Linux kernel, the following vulnerability has been resolved: arm64/sve: Discard stale CPU state when handling SVE traps The logic for handling SVE traps manipulates saved FPSIMD/SVE state incorrectly, and a race with preemption can result in a task having TIFSVE set and TIFFOREIGNFPSTATE clear even though the live CPU state is stale (e.g. with SVE traps enabled). This has been observed to result in warnings from dosveacc() where SVE traps are not expected while TIFSVE is set: | if (testandsetthreadflag(TIFSVE)) | WARNON(1); / SVE access shouldn't have trapped / Warnings of this form have been reported intermittently, e.g. https://lore.kernel.org/linux-arm-kernel/CA+G9fYtEGeDhY2Ms7+L7NKsLYUomGsgqpdBj+QwDLeSg=JhGg@mail.gmail.com/ https://lore.kernel.org/linux-arm-kernel/000000000000511e9a060ce5a45c@google.com/ The race can occur when the SVE trap handler is preempted before and after manipulating the saved FPSIMD/SVE state, starting and ending on the same CPU, e.g. | void dosveacc(unsigned long esr, struct ptregs regs) | { | // Trap on CPU 0 with TIFSVE clear, SVE traps enabled | // task->fpsimdcpu is 0. | // percpuptr(&fpsimdlaststate, 0) is task. | | ... | | // Preempted; migrated from CPU 0 to CPU 1. | // TIFFOREIGNFPSTATE is set. | | getcpufpsimdcontext(); | | if (testandsetthreadflag(TIFSVE)) | WARNON(1); / SVE access shouldn't have trapped / | | sveinitregs() { | if (!testthreadflag(TIFFOREIGNFPSTATE)) { | ... | } else { | fpsimdtosve(current); | current->thread.fptype = FPSTATESVE; | } | } | | putcpufpsimdcontext(); | | // Preempted; migrated from CPU 1 to CPU 0. | // task->fpsimdcpu is still 0 | // If percpuptr(&fpsimdlaststate, 0) is still task then: | // - Stale HW state is reused (with SVE traps enabled) | // - TIFFOREIGNFPSTATE is cleared | // - A return to userspace skips HW state restore | } Fix the case where the state is not live and TIFFOREIGNFPSTATE is set by calling fpsimdflushtaskstate() to detach from the saved CPU state. This ensures that a subsequent context switch will not reuse the stale CPU state, and will instead set TIFFOREIGNFPSTATE, forcing the new state to be reloaded from memory prior to a return to userspace.

Affected Software

149 affected componentsFixes available

ubuntu/linux-hwe-edge*

ubuntu/linux-aws-5.0*

ubuntu/linux-aws-5.3*

ubuntu/linux-azure*

ubuntu/linux-azure-5.3*

ubuntu/linux-azure-edge*

ubuntu/linux-gcp*

ubuntu/linux-gcp-5.3*

ubuntu/linux-gke-4.15*

ubuntu/linux-gke-5.4*

ubuntu/linux-gkeop-5.4*

ubuntu/linux-hwe*

ubuntu/linux-oem*

ubuntu/linux-oracle-5.0*

ubuntu/linux-oracle-5.3*

ubuntu/linux-aws-5.15<5.15.0-1080.87~20.04.1

5.15.0-1080.87~20.04.1

ubuntu/linux-azure-5.15<5.15.0-1086.95~20.04.1

5.15.0-1086.95~20.04.1

ubuntu/linux-gcp-5.15<5.15.0-1081.90~20.04.1

5.15.0-1081.90~20.04.1

ubuntu/linux-hwe-5.15<5.15.0-136.147~20.04.1

5.15.0-136.147~20.04.1

ubuntu/linux-ibm-5.15<5.15.0-1074.77~20.04.1

5.15.0-1074.77~20.04.1

ubuntu/linux-intel-iotg-5.15<5.15.0-1077.83~20.04.1

5.15.0-1077.83~20.04.1

ubuntu/linux-lowlatency-hwe-5.15<5.15.0-135.146~20.04.1

5.15.0-135.146~20.04.1

ubuntu/linux-oracle-5.15<5.15.0-1077.83~20.04.1

5.15.0-1077.83~20.04.1

ubuntu/linux-riscv-5.15<5.15.0-1075.79~20.04.1

5.15.0-1075.79~20.04.1

ubuntu/linux-aws-5.11*

ubuntu/linux-aws-5.13*

ubuntu/linux-aws-5.8*

ubuntu/linux-azure-5.11*

ubuntu/linux-azure-5.13*

ubuntu/linux-azure-5.8*

ubuntu/linux-azure-fde*

ubuntu/linux-gcp-5.11*

ubuntu/linux-gcp-5.13*

ubuntu/linux-gcp-5.8*

ubuntu/linux-gke*

ubuntu/linux-gke-5.15*

ubuntu/linux-gkeop*

ubuntu/linux-gkeop-5.15*

ubuntu/linux-hwe-5.11*

ubuntu/linux-hwe-5.13*

ubuntu/linux-hwe-5.8*

ubuntu/linux-intel-5.13*

ubuntu/linux-nvidia-tegra-5.15<5.15.0-1039.39~20.04.1

5.15.0-1039.39~20.04.1

ubuntu/linux-oem-5.10*

ubuntu/linux-oem-5.13*

ubuntu/linux-oem-5.6*

ubuntu/linux-oracle-5.11*

ubuntu/linux-oracle-5.13*

ubuntu/linux-oracle-5.8*

ubuntu/linux-raspi2*

ubuntu/linux-riscv*

ubuntu/linux-riscv-5.11*

ubuntu/linux-riscv-5.8*

ubuntu/linux<5.15.0-135.146

5.15.0-135.146

ubuntu/linux-allwinner-5.19*

ubuntu/linux-aws<5.15.0-1080.87

5.15.0-1080.87

ubuntu/linux-aws-5.19*

ubuntu/linux-aws-6.2*

ubuntu/linux-aws-6.5*

ubuntu/linux-aws-6.8<6.8.0-1027.29~22.04.1

6.8.0-1027.29~22.04.1

ubuntu/linux-azure<5.15.0-1084.93

5.15.0-1084.93

ubuntu/linux-azure-5.19*

ubuntu/linux-azure-6.2*

ubuntu/linux-azure-6.5*

ubuntu/linux-azure-6.8<6.8.0-1027.32~22.04.1

6.8.0-1027.32~22.04.1

ubuntu/linux-azure-fde<5.15.0-1084.93.1

5.15.0-1084.93.1

ubuntu/linux-azure-fde-5.19*

ubuntu/linux-azure-fde-6.2*

ubuntu/linux-gcp<5.15.0-1079.88

5.15.0-1079.88

ubuntu/linux-gcp-5.19*

ubuntu/linux-gcp-6.2*

ubuntu/linux-gcp-6.5*

ubuntu/linux-gcp-6.8<6.8.0-1028.30~22.04.1

6.8.0-1028.30~22.04.1

ubuntu/linux-gke<5.15.0-1077.83

5.15.0-1077.83

ubuntu/linux-gkeop<5.15.0-1062.70

5.15.0-1062.70

ubuntu/linux-hwe-5.19*

ubuntu/linux-hwe-6.2*

ubuntu/linux-hwe-6.5*

ubuntu/linux-hwe-6.8<6.8.0-58.60~22.04.1

6.8.0-58.60~22.04.1

ubuntu/linux-ibm<5.15.0-1072.75

5.15.0-1072.75

ubuntu/linux-ibm-6.8<6.8.0-1024.24~22.04.1

6.8.0-1024.24~22.04.1

ubuntu/linux-intel-iot-realtime<5.15.0-1073.75

5.15.0-1073.75

ubuntu/linux-intel-iotg<5.15.0-1075.81

5.15.0-1075.81

ubuntu/linux-kvm<5.15.0-1076.81

5.15.0-1076.81

ubuntu/linux-lowlatency<5.15.0-135.146

5.15.0-135.146

ubuntu/linux-lowlatency-hwe-5.19*

ubuntu/linux-lowlatency-hwe-6.2*

ubuntu/linux-lowlatency-hwe-6.5*

ubuntu/linux-lowlatency-hwe-6.8<6.8.0-58.60.1~22.04.1

6.8.0-58.60.1~22.04.1

ubuntu/linux-nvidia<5.15.0-1074.75

5.15.0-1074.75

ubuntu/linux-nvidia-6.2*

ubuntu/linux-nvidia-6.5*

ubuntu/linux-nvidia-6.8<6.8.0-1026.29~22.04.1

6.8.0-1026.29~22.04.1

ubuntu/linux-nvidia-tegra<5.15.0-1033.33

5.15.0-1033.33

ubuntu/linux-nvidia-tegra-igx<5.15.0-1021.21

5.15.0-1021.21

ubuntu/linux-oem-5.17*

ubuntu/linux-oem-6.0*

ubuntu/linux-oem-6.1*

ubuntu/linux-oem-6.5*

ubuntu/linux-oracle<5.15.0-1077.83

5.15.0-1077.83

ubuntu/linux-oracle-6.5*

ubuntu/linux-oracle-6.8<6.8.0-1024.25~22.04.1

6.8.0-1024.25~22.04.1

ubuntu/linux-raspi<5.15.0-1074.77

5.15.0-1074.77

ubuntu/linux-realtime*

ubuntu/linux-riscv*

ubuntu/linux-riscv-5.19*

ubuntu/linux-riscv-6.5*

ubuntu/linux-riscv-6.8<6.8.0-58.60.1~22.04.1

6.8.0-58.60.1~22.04.1

ubuntu/linux-starfive-5.19*

ubuntu/linux-starfive-6.2*

ubuntu/linux-starfive-6.5*

ubuntu/linux-xilinx-zynqmp<5.15.0-1044.48

5.15.0-1044.48

ubuntu/linux-bluefield<5.15.0-1062.64

5.15.0-1062.64

ubuntu/linux-realtime<5.15.0-1080.88

5.15.0-1080.88

ubuntu/linux-realtime-6.8<6.8.1-1020.21~22.04.1

6.8.1-1020.21~22.04.1

ubuntu/linux-aws-fips*

ubuntu/linux-azure-fips*

ubuntu/linux-fips*

ubuntu/linux-gcp-fips*

ubuntu/linux-aws-fips<5.15.0-1080.87+fips1

5.15.0-1080.87+fips1

ubuntu/linux-azure-fips<5.15.0-1083.92+fips1

5.15.0-1083.92+fips1

ubuntu/linux-fips<5.15.0-135.146+fips1

5.15.0-135.146+fips1

ubuntu/linux-gcp-fips<5.15.0-1079.88+fips1

5.15.0-1079.88+fips1

ubuntu/linux<6.8.0-58.60

6.8.0-58.60

ubuntu/linux-aws<6.8.0-1027.29

6.8.0-1027.29

ubuntu/linux-azure<6.8.0-1027.32

6.8.0-1027.32

ubuntu/linux-azure-6.11<6.11.0-1012.12~24.04.1

6.11.0-1012.12~24.04.1

ubuntu/linux-azure-nvidia<6.8.0-1014.15

6.8.0-1014.15

ubuntu/linux-gcp<6.8.0-1028.30

6.8.0-1028.30

ubuntu/linux-gcp-6.11<6.11.0-1011.11~24.04.1

6.11.0-1011.11~24.04.1

ubuntu/linux-gke<6.8.0-1023.27

6.8.0-1023.27

ubuntu/linux-gkeop<6.8.0-1010.12

6.8.0-1010.12

ubuntu/linux-ibm<6.8.0-1024.24

6.8.0-1024.24

ubuntu/linux-lowlatency<6.8.0-58.60.1

6.8.0-58.60.1

ubuntu/linux-nvidia<6.8.0-1026.29

6.8.0-1026.29

ubuntu/linux-nvidia-6.11<6.11.0-1007.7

6.11.0-1007.7

ubuntu/linux-nvidia-lowlatency<6.8.0-1026.29.1

6.8.0-1026.29.1

ubuntu/linux-nvidia-tegra<6.8.0-1008.8

6.8.0-1008.8

ubuntu/linux-oem-6.11<6.11.0-1015.15

6.11.0-1015.15

ubuntu/linux-oem-6.8<6.8.0-1026.26

6.8.0-1026.26

ubuntu/linux-oracle<6.8.0-1024.25

6.8.0-1024.25

ubuntu/linux-raspi<6.8.0-1028.32

6.8.0-1028.32

ubuntu/linux-raspi-realtime*

ubuntu/linux-realtime*

ubuntu/linux-riscv<6.8.0-58.60.1

6.8.0-58.60.1

ubuntu/linux-xilinx<6.8.0-1017.18

6.8.0-1017.18

ubuntu/linux-raspi-realtime<6.8.0-2023.24

6.8.0-2023.24

ubuntu/linux-realtime<6.8.1-1020.21

6.8.1-1020.21

ubuntu/linux-fips<6.8.0-78.78+fips1

6.8.0-78.78+fips1

Remediation

Recommended actions to resolve this vulnerability, in priority order.

Upgrade
Upgrade ubuntu/linux-aws-5.15 to a version that resolves this vulnerability.
Fixed in 5.15.0-1080.87~20.04.1
Upgrade
Upgrade ubuntu/linux-azure-5.15 to a version that resolves this vulnerability.
Fixed in 5.15.0-1086.95~20.04.1
Upgrade
Upgrade ubuntu/linux-gcp-5.15 to a version that resolves this vulnerability.
Fixed in 5.15.0-1081.90~20.04.1
Upgrade
Upgrade ubuntu/linux-hwe-5.15 to a version that resolves this vulnerability.
Fixed in 5.15.0-136.147~20.04.1
Upgrade
Upgrade ubuntu/linux-ibm-5.15 to a version that resolves this vulnerability.
Fixed in 5.15.0-1074.77~20.04.1
Upgrade
Upgrade ubuntu/linux-intel-iotg-5.15 to a version that resolves this vulnerability.
Fixed in 5.15.0-1077.83~20.04.1
Upgrade
Upgrade ubuntu/linux-lowlatency-hwe-5.15 to a version that resolves this vulnerability.
Fixed in 5.15.0-135.146~20.04.1
Upgrade
Upgrade ubuntu/linux-oracle-5.15 to a version that resolves this vulnerability.
Fixed in 5.15.0-1077.83~20.04.1
Upgrade
Upgrade ubuntu/linux-riscv-5.15 to a version that resolves this vulnerability.
Fixed in 5.15.0-1075.79~20.04.1
Upgrade
Upgrade ubuntu/linux-nvidia-tegra-5.15 to a version that resolves this vulnerability.
Fixed in 5.15.0-1039.39~20.04.1
Upgrade
Upgrade ubuntu/linux to a version that resolves this vulnerability.
Fixed in 5.15.0-135.146
Upgrade
Upgrade ubuntu/linux-aws to a version that resolves this vulnerability.
Fixed in 5.15.0-1080.87
Upgrade
Upgrade ubuntu/linux-aws-6.8 to a version that resolves this vulnerability.
Fixed in 6.8.0-1027.29~22.04.1
Upgrade
Upgrade ubuntu/linux-azure to a version that resolves this vulnerability.
Fixed in 5.15.0-1084.93
Upgrade
Upgrade ubuntu/linux-azure-6.8 to a version that resolves this vulnerability.
Fixed in 6.8.0-1027.32~22.04.1
Upgrade
Upgrade ubuntu/linux-azure-fde to a version that resolves this vulnerability.
Fixed in 5.15.0-1084.93.1
Upgrade
Upgrade ubuntu/linux-gcp to a version that resolves this vulnerability.
Fixed in 5.15.0-1079.88
Upgrade
Upgrade ubuntu/linux-gcp-6.8 to a version that resolves this vulnerability.
Fixed in 6.8.0-1028.30~22.04.1
Upgrade
Upgrade ubuntu/linux-gke to a version that resolves this vulnerability.
Fixed in 5.15.0-1077.83
Upgrade
Upgrade ubuntu/linux-gkeop to a version that resolves this vulnerability.
Fixed in 5.15.0-1062.70
Upgrade
Upgrade ubuntu/linux-hwe-6.8 to a version that resolves this vulnerability.
Fixed in 6.8.0-58.60~22.04.1
Upgrade
Upgrade ubuntu/linux-ibm to a version that resolves this vulnerability.
Fixed in 5.15.0-1072.75
Upgrade
Upgrade ubuntu/linux-ibm-6.8 to a version that resolves this vulnerability.
Fixed in 6.8.0-1024.24~22.04.1
Upgrade
Upgrade ubuntu/linux-intel-iot-realtime to a version that resolves this vulnerability.
Fixed in 5.15.0-1073.75
Upgrade
Upgrade ubuntu/linux-intel-iotg to a version that resolves this vulnerability.
Fixed in 5.15.0-1075.81
Upgrade
Upgrade ubuntu/linux-kvm to a version that resolves this vulnerability.
Fixed in 5.15.0-1076.81
Upgrade
Upgrade ubuntu/linux-lowlatency to a version that resolves this vulnerability.
Fixed in 5.15.0-135.146
Upgrade
Upgrade ubuntu/linux-lowlatency-hwe-6.8 to a version that resolves this vulnerability.
Fixed in 6.8.0-58.60.1~22.04.1
Upgrade
Upgrade ubuntu/linux-nvidia to a version that resolves this vulnerability.
Fixed in 5.15.0-1074.75
Upgrade
Upgrade ubuntu/linux-nvidia-6.8 to a version that resolves this vulnerability.
Fixed in 6.8.0-1026.29~22.04.1
Upgrade
Upgrade ubuntu/linux-nvidia-tegra to a version that resolves this vulnerability.
Fixed in 5.15.0-1033.33
Upgrade
Upgrade ubuntu/linux-nvidia-tegra-igx to a version that resolves this vulnerability.
Fixed in 5.15.0-1021.21
Upgrade
Upgrade ubuntu/linux-oracle to a version that resolves this vulnerability.
Fixed in 5.15.0-1077.83
Upgrade
Upgrade ubuntu/linux-oracle-6.8 to a version that resolves this vulnerability.
Fixed in 6.8.0-1024.25~22.04.1
Upgrade
Upgrade ubuntu/linux-raspi to a version that resolves this vulnerability.
Fixed in 5.15.0-1074.77
Upgrade
Upgrade ubuntu/linux-riscv-6.8 to a version that resolves this vulnerability.
Fixed in 6.8.0-58.60.1~22.04.1
Upgrade
Upgrade ubuntu/linux-xilinx-zynqmp to a version that resolves this vulnerability.
Fixed in 5.15.0-1044.48
Upgrade
Upgrade ubuntu/linux-bluefield to a version that resolves this vulnerability.
Fixed in 5.15.0-1062.64
Upgrade
Upgrade ubuntu/linux-realtime to a version that resolves this vulnerability.
Fixed in 5.15.0-1080.88
Upgrade
Upgrade ubuntu/linux-realtime-6.8 to a version that resolves this vulnerability.
Fixed in 6.8.1-1020.21~22.04.1
Upgrade
Upgrade ubuntu/linux-aws-fips to a version that resolves this vulnerability.
Fixed in 5.15.0-1080.87+fips1
Upgrade
Upgrade ubuntu/linux-azure-fips to a version that resolves this vulnerability.
Fixed in 5.15.0-1083.92+fips1
Upgrade
Upgrade ubuntu/linux-fips to a version that resolves this vulnerability.
Fixed in 5.15.0-135.146+fips1
Upgrade
Upgrade ubuntu/linux-gcp-fips to a version that resolves this vulnerability.
Fixed in 5.15.0-1079.88+fips1
Upgrade
Upgrade ubuntu/linux to a version that resolves this vulnerability.
Fixed in 6.8.0-58.60
Upgrade
Upgrade ubuntu/linux-aws to a version that resolves this vulnerability.
Fixed in 6.8.0-1027.29
Upgrade
Upgrade ubuntu/linux-azure to a version that resolves this vulnerability.
Fixed in 6.8.0-1027.32
Upgrade
Upgrade ubuntu/linux-azure-6.11 to a version that resolves this vulnerability.
Fixed in 6.11.0-1012.12~24.04.1
Upgrade
Upgrade ubuntu/linux-azure-nvidia to a version that resolves this vulnerability.
Fixed in 6.8.0-1014.15
Upgrade
Upgrade ubuntu/linux-gcp to a version that resolves this vulnerability.
Fixed in 6.8.0-1028.30
Upgrade
Upgrade ubuntu/linux-gcp-6.11 to a version that resolves this vulnerability.
Fixed in 6.11.0-1011.11~24.04.1
Upgrade
Upgrade ubuntu/linux-gke to a version that resolves this vulnerability.
Fixed in 6.8.0-1023.27
Upgrade
Upgrade ubuntu/linux-gkeop to a version that resolves this vulnerability.
Fixed in 6.8.0-1010.12
Upgrade
Upgrade ubuntu/linux-ibm to a version that resolves this vulnerability.
Fixed in 6.8.0-1024.24
Upgrade
Upgrade ubuntu/linux-lowlatency to a version that resolves this vulnerability.
Fixed in 6.8.0-58.60.1
Upgrade
Upgrade ubuntu/linux-nvidia to a version that resolves this vulnerability.
Fixed in 6.8.0-1026.29
Upgrade
Upgrade ubuntu/linux-nvidia-6.11 to a version that resolves this vulnerability.
Fixed in 6.11.0-1007.7
Upgrade
Upgrade ubuntu/linux-nvidia-lowlatency to a version that resolves this vulnerability.
Fixed in 6.8.0-1026.29.1
Upgrade
Upgrade ubuntu/linux-nvidia-tegra to a version that resolves this vulnerability.
Fixed in 6.8.0-1008.8
Upgrade
Upgrade ubuntu/linux-oem-6.11 to a version that resolves this vulnerability.
Fixed in 6.11.0-1015.15
Upgrade
Upgrade ubuntu/linux-oem-6.8 to a version that resolves this vulnerability.
Fixed in 6.8.0-1026.26
Upgrade
Upgrade ubuntu/linux-oracle to a version that resolves this vulnerability.
Fixed in 6.8.0-1024.25
Upgrade
Upgrade ubuntu/linux-raspi to a version that resolves this vulnerability.
Fixed in 6.8.0-1028.32
Upgrade
Upgrade ubuntu/linux-riscv to a version that resolves this vulnerability.
Fixed in 6.8.0-58.60.1
Upgrade
Upgrade ubuntu/linux-xilinx to a version that resolves this vulnerability.
Fixed in 6.8.0-1017.18
Upgrade
Upgrade ubuntu/linux-raspi-realtime to a version that resolves this vulnerability.
Fixed in 6.8.0-2023.24
Upgrade
Upgrade ubuntu/linux-realtime to a version that resolves this vulnerability.
Fixed in 6.8.1-1020.21
Upgrade
Upgrade ubuntu/linux-fips to a version that resolves this vulnerability.
Fixed in 6.8.0-78.78+fips1
Compensating control
In the SVE trap handling path, when the state is not live and TIF_FOREIGN_FPSTATE is set, call fpsimd_flush_task_state() to detach the task from the saved CPU state and prevent stale hardware state reuse.

Event History

Nov 19, 2024

CVE Published

via OSV·02:16 AM

Data Sourced

via OSV·02:16 AM

DescriptionSeverityAffected Software

Frequently Asked Questions

Which systems are realistically exposed to this issue?

The issue affects Arm64 systems using SVE, where SVE traps are enabled. The listed Ubuntu kernel packages are linux-realtime, linux-azure, linux-gcp, linux-gke, linux-gkeop, linux-riscv, linux-fips, and linux-azure-fde.

What access and conditions does exploitation require?