CVE-2025-21645
Linux Kernel 5.15.95 – 5.16
Raw vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:HSummary
CVE-2025-21645 is a medium-severity an unspecified weakness vulnerability in Linux Linux Kernel. Its CVSS base score is 5.5 (Medium).
Operationally, ranked at the 15th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.
The strongest mitigations our analysis identified map to SI-2 (Flaw Remediation) and CM-6 (Configuration Settings) — see the control section below for these in your framework.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2025-2594
Vulnerability Data
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…
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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.]
- CWE(s)
Related Threats
CVEs Like This One
Affected Assets
Mitigating Controls
Control response
Mitigating Controls (NIST 800-53 r5) AI
Directly requires applying the kernel patch that restricts amd_pmc_suspend_handler to only the .suspend path, eliminating the unbalanced IRQ1 wake_depth decrement.
Enables continuous monitoring of kernel logs for the specific 'Unbalanced IRQ 1 wake disable' WARNING that signals the CVE has been triggered during S4.
Allows enforcement of hardened power-management settings that avoid the exact hibernation sequence (fresh boot to S4 without prior s2idle) required to reproduce the flaw.