CVE-2025-21645
MediumCVSS 5.5Exploitation Probability (EPSS)
Low risk15th percentile - higher than 15% of all known CVEs
Summary
A vulnerability in the Linux kernel's AMD PMC driver (platform/x86/amd/pmc) causes an unbalanced IRQ1 wake disable when i8042 did not enable the wakeup, leading to a WARN() warning and potential wake_depth underflow.
Risk Assessment
The risk involves logging unpleasant WARN() warnings in the system, which can mask more serious issues and lead to instability during hibernation (S4) without prior s2idle sleep.
Recommendation
Immediately update the Linux kernel to a version containing the fix that restricts the PMC suspend handler invocation to the same dev_pm_ops handlers as i8042_pm_suspend(), i.e., only the .suspend handler.
Original NVD description (English source)
In the Linux kernel, the following vulnerability has been resolved: platform/x86/amd/pmc: Only disable IRQ1 wakeup where i8042 actually enabled it Wakeup for IRQ1 should be disabled only in cases where i8042 had actually enabled it, otherwise "wake_depth" for this IRQ will try to drop below zero and there will be an unpleasant WARN() logged: kernel: atkbd serio0: Disabling IRQ1 wakeup source to avoid platform firmware bug kernel: ------------[ cut here ]------------ kernel: Unbalanced IRQ 1 wake disable kernel: WARNING: CPU: 10 PID: 6431 at kernel/irq/manage.c:920 irq_set_irq_wake+0x147/0x1a0 The PMC driver uses DEFINE_SIMPLE_DEV_PM_OPS() to define its dev_pm_ops which sets amd_pmc_suspend_handler() to the .suspend, .freeze, and .poweroff handlers. i8042_pm_suspend(), however, is only set as the .suspend handler. Fix the issue by call PMC suspend handler only from the same set of dev_pm_ops handlers as i8042_pm_suspend(), which currently means just the .suspend handler. To reproduce this issue try hibernating (S4) the machine after a fresh boot without putting it into s2idle first. [ij: edited the commit message.]