CVE-2023-54160 firmware: arm_sdei: Fix sleep from invalid context BUG
A bug in the Linux kernel SDEI driver causes a system crash when running a preempt-rt kernel, leading to denial of service.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2023-54160?
CVE-2023-54160 is a denial of service vulnerability in Linux, published on 24 Dec 2025. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
In the Linux kernel, the following vulnerability has been resolved:
firmware: arm_sdei: Fix sleep from invalid context BUG
Running a preempt-rt (v6.2-rc3-rt1) based kernel on an Ampere Altra triggers:
BUG: sleeping function called from invalid context at kernel/locking/spinlock_rt.c:46 in_atomic(): 0, irqs_disabled(): 128, non_block: 0, pid: 24, name: cpuhp/0 preempt_count: 0, expected: 0 RCU nest depth: 0, expected: 0 3 locks held by cpuhp/0/24: #0: ffffda30217c70d0 (cpu_hotplug_lock){++++}-{0:0}, at: cpuhp_thread_fun+0x5c/0x248 #1: ffffda30217c7120 (cpuhp_state-up){+.+.}-{0:0}, at: cpuhp_thread_fun+0x5c/0x248 #2: ffffda3021c711f0 (sdei_list_lock){....}-{3:3}, at: sdei_cpuhp_up+0x3c/0x130 irq event stamp: 36 hardirqs last enabled at (35): [<ffffda301e85b7bc>] finish_task_switch+0xb4/0x2b0 hardirqs last disabled at (36): [<ffffda301e812fec>] cpuhp_thread_fun+0x21c/0x248 softirqs last enabled at (0): [<ffffda301e80b184>] copy_process+0x63c/0x1ac0 softirqs last disabled at (0): [<0000000000000000>] 0x0 CPU: 0 PID: 24 Comm: cpuhp/0 Not tainted 5.19.0-rc3-rt5-[...] Hardware name: WIWYNN Mt.Jade Server [...] Call trace: dump_backtrace+0x114/0x120 show_stack+0x20/0x70 dump_stack_lvl+0x9c/0xd8 dump_stack+0x18/0x34 __might_resched+0x188/0x228 rt_spin_lock+0x70/0x120 sdei_cpuhp_up+0x3c/0x130 cpuhp_invoke_callback+0x250/0xf08 cpuhp_thread_fun+0x120/0x248 smpboot_thread_fn+0x280/0x320 kthread+0x130/0x140 ret_from_fork+0x10/0x20
sdei_cpuhp_up() is called in the STARTING hotplug section, which runs with interrupts disabled. Use a CPUHP_AP_ONLINE_DYN entry instead to execute the cpuhp cb later, with preemption enabled.
SDEI originally got its own cpuhp slot to allow interacting with perf. It got superseded by pNMI and this early slot is not relevant anymore. [1]
Some SDEI calls (e.g. SDEI_1_0_FN_SDEI_PE_MASK) take actions on the calling CPU. It is checked that preemption is disabled for them. _ONLINE cpuhp cb are executed in the 'per CPU hotplug thread'. Preemption is enabled in those threads, but their cpumask is limited to 1 CPU. Move 'WARN_ON_ONCE(preemptible())' statements so that SDEI cpuhp cb don't trigger them.
Also add a check for the SDEI_1_0_FN_SDEI_PRIVATE_RESET SDEI call which acts on the calling CPU.
[1]: https://lore.kernel.org/all/[email protected]/
Which versions are affected by CVE-2023-54160?
How do I fix CVE-2023-54160?
Apply the vendor's patch.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2023-54160 being exploited?
There is no known exploitation of CVE-2023-54160 in the wild and no public exploit code.
Sources
Also known as BELL-CVE-2023-54160, DEBIAN-CVE-2023-54160, GHSA-jfm8-wf93-6c4c, UBUNTU-CVE-2023-54160.