CVE-2025-38335
Our Analysis: Embedded
Our model has classified this vulnerability as relevant to Embedded Systems, helping your team prioritize efforts effectively.
Description
In the Linux kernel, the following vulnerability has been resolved:
Input: gpio-keys - fix a sleep while atomic with PREEMPT_RT
When enabling PREEMPT_RT, the gpio_keys_irq_timer() callback runs in
hard irq context, but the input_event() takes a spin_lock, which isn't
allowed there as it is converted to a rt_spin_lock().
[ 4054.289999] BUG: sleeping function called from invalid context at kernel/locking/spinlock_rt.c:48
[ 4054.290028] in_atomic(): 1, irqs_disabled(): 1, non_block: 0, pid: 0, name: swapper/0
...
[ 4054.290195] __might_resched+0x13c/0x1f4
[ 4054.290209] rt_spin_lock+0x54/0x11c
[ 4054.290219] input_event+0x48/0x80
[ 4054.290230] gpio_keys_irq_timer+0x4c/0x78
[ 4054.290243] __hrtimer_run_queues+0x1a4/0x438
[ 4054.290257] hrtimer_interrupt+0xe4/0x240
[ 4054.290269] arch_timer_handler_phys+0x2c/0x44
[ 4054.290283] handle_percpu_devid_irq+0x8c/0x14c
[ 4054.290297] handle_irq_desc+0x40/0x58
[ 4054.290307] generic_handle_domain_irq+0x1c/0x28
[ 4054.290316] gic_handle_irq+0x44/0xcc
Considering the gpio_keys_irq_isr() can run in any context, e.g. it can
be threaded, it seems there's no point in requesting the timer isr to
run in hard irq context.
Relax the hrtimer not to use the hard context.