CVE-2023-53216

  • Published: 2025-09-15T15:15:48.273

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.]

Related CVE by CWE

No related CWE found.

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How to fix CVE-2023-53216

CVE-2023-53216 is a unknown severity vulnerability affecting the affected product.

Description: 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: […]

Exploit Difficulty: HARD
⏱️ Time to exploit: > 4 hours
🛠️ Required skills: Advanced security expertise
💰 Public exploits: Rare or not public

How to Fix:

1 Identify affected systems

- Check if you're running the affected product

2 Immediate actions

- Update to the latest patched version
- If patching is not immediately possible: restrict network exposure, apply least-privilege access

3 Verification

- Test the fix in a staging environment first
- Review logs for signs of exploitation
- Monitor for IOCs (Indicators of Compromise)

4 Long-term prevention

- Enable automatic security updates
- Set up vulnerability monitoring
- Review and harden security configurations

Exploit Difficulty Assessment

HARD
⏱️ Time to Exploit: > 4 hours
🛠️ Skills Required: Advanced security expertise
💰 Public Exploits: Rare or not public

Vulnerability Timeline

Sep 15, 2025
Vulnerability Published

CVE details first published to NVD database

Nov 12, 2025
Imported to Database

Added to this CVE tracking system

Detection Rules & IOCs

No specific detection rules generated for this vulnerability type.

No vendor/product data available.