In the Linux kernel, the following vulnerability has been resolved:
arm64: efi: Make efi_rt_lock a raw_spinlock
Running a rt-kernel base on 6.2.0-rc3-rt1 on an Ampere Altra outputs the following: BUG: sleeping function called from invalid context at kernel/locking/spinlock_rt.c:46 in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 9, name: kworker/u320:0 preempt_count: 2, expected: 0 RCU nest depth: 0, expected: 0 3 locks held by kworker/u320:0/9: #0: ffff3fff8c27d128 ((wq_completion)efi_rts_wq){+.+.}-{0:0}, at: process_one_work (./include/linux/atomic/atomic-long.h:41) #1: ffff80000861bdd0 ((work_completion)(&efi_rts_work.work)){+.+.}-{0:0}, at: process_one_work (./include/linux/atomic/atomic-long.h:41) #2: ffffdf7e1ed3e460 (efi_rt_lock){+.+.}-{3:3}, at: efi_call_rts (drivers/firmware/efi/runtime-wrappers.c:101) Preemption disabled at: efi_virtmap_load (./arch/arm64/include/asm/mmu_context.h:248) CPU: 0 PID: 9 Comm: kworker/u320:0 Tainted: G W 6.2.0-rc3-rt1 Hardware name: WIWYNN Mt.Jade Server System B81.03001.0005/Mt.Jade Motherboard, BIOS 1.08.20220218 (SCP: 1.08.20220218) 2022/02/18 Workqueue: efi_rts_wq efi_call_rts Call trace: dump_backtrace (arch/arm64/kernel/stacktrace.c:158) show_stack (arch/arm64/kernel/stacktrace.c:165) dump_stack_lvl (lib/dump_stack.c:107 (discriminator 4)) dump_stack (lib/dump_stack.c:114) __might_resched (kernel/sched/core.c:10134) rt_spin_lock (kernel/locking/rtmutex.c:1769 (discriminator 4)) efi_call_rts (drivers/firmware/efi/runtime-wrappers.c:101) [...]
This seems to come from commit ff7a167961d1 ("arm64: efi: Execute runtime services from a dedicated stack") which adds a spinlock. This spinlock is taken through: efi_call_rts() \-efi_call_virt() \-efi_call_virt_pointer() \-arch_efi_call_virt_setup()
Make 'efi_rt_lock' a raw_spinlock to avoid being preempted.
[ardb: The EFI runtime services are called with a different set of translation tables, and are permitted to use the SIMD registers. The context switch code preserves/restores neither, and so EFI calls must be made with preemption disabled, rather than only disabling migration.]
CVSS Details
- CVSS 3.1 Base Score: 7.8
- CVSS 3.1 Vector: (CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H)
Covered by Rapid7
| Product | Vendor Advisory | Solution File | Added | Published |
|---|---|---|---|---|
| Amazon Linux Ami 2 | — | Upgrade kernel-debuginfoUpgrade kernel-livepatch-5.15.104-63.140Upgrade bpftool-debuginfoUpgrade kernel-debuginfo-common-aarch64Upgrade kernel-debuginfo-common-x86_64Upgrade kernel-toolsUpgrade python-perfUpgrade kernelUpgrade kernel-tools-debuginfoUpgrade perfUpgrade bpftoolUpgrade kernel-livepatch-5.10.176-157.645Upgrade kernel-headersUpgrade perf-debuginfoUpgrade kernel-develUpgrade kernel-tools-develUpgrade python-perf-debuginfo | May 20, 2026 | May 20, 2026 |
| Amazon_linux_2023 | — | Upgrade bpftool-debuginfoUpgrade kernel-livepatch-6.1.19-30.43Upgrade kernel-debuginfo-common-x86_64Upgrade kernel-toolsUpgrade bpftoolUpgrade kernel-tools-debuginfoUpgrade python3-perfUpgrade kernel-develUpgrade perfUpgrade kernel-headersUpgrade kernel-tools-develUpgrade kernel-debuginfoUpgrade python3-perf-debuginfoUpgrade kernel-debuginfo-common-aarch64Upgrade kernel-libbpf-staticUpgrade kernel-libbpf-develUpgrade perf-debuginfoUpgrade kernelUpgrade kernel-libbpf | Sep 30, 2025 | Sep 15, 2025 |
| Debian | — | Upgrade linux | Sep 17, 2025 | Sep 17, 2025 |
| Huawei Euleros 2_0_sp13 | — | Upgrade python3-perfUpgrade kernel-tools-libsUpgrade bpftoolUpgrade kernelUpgrade kernel-abi-stablelistsUpgrade kernel-tools | Dec 12, 2025 | Dec 11, 2025 |
| Ubuntu | — | Upgrade linux-realtimeUpgrade linux-nvidia-tegra-5.15Upgrade linux-azure-5.15Upgrade linux-intel-iot-realtimeUpgrade linux-gkeopUpgrade linux-oracleUpgrade linux-intel-iotgUpgrade linux-riscv-5.15Upgrade linuxUpgrade linux-awsUpgrade linux-gcpUpgrade linux-ibm-5.15Upgrade linux-nvidia-tegra-igxUpgrade linux-ibmUpgrade linux-nvidiaUpgrade linux-nvidia-tegraUpgrade linux-kvmUpgrade linux-hwe-5.15Upgrade linux-aws-5.15Upgrade linux-bluefieldUpgrade linux-azureUpgrade linux-oracle-5.15Upgrade linux-lowlatency-hwe-5.15Upgrade linux-lowlatencyUpgrade linux-gcp-5.15Upgrade linux-intel-iotg-5.15Upgrade linux-raspi | Sep 19, 2025 | Sep 16, 2025 |
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