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CVE Record

CVE-2025-21803: LoongArch: Fix warnings during S3 suspend

In the Linux kernel, the following vulnerability has been resolved: LoongArch: Fix warnings during S3 suspend The enable_gpe_wakeup() function calls acpi_enable_all_wakeup_gpes(), and the later one may call the preempt_schedule_common() function, resulting in a thread switch and causing the CPU to be in an interrupt enabled state after the enable_gpe_wakeup() function returns, leading to the warnings as follow. [ C0] WARNING: ... at kernel/time/timekeeping.c:845 ktime_get+0xbc/0xc8 [ C0] ... [ C0] Call Trace: [ C0] [<90000000002243b4>] show_stack+0x64/0x188 [ C0] [<900000000164673c>] dump_stack_lvl+0x60/0x88 [ C0] [<90000000002687e4>] __warn+0x8c/0x148 [ C0] [<90000000015e9978>] report_bug+0x1c0/0x2b0 [ C0] [<90000000016478e4>] do_bp+0x204/0x3b8 [ C0] [<90000000025b1924>] exception_handlers+0x1924/0x10000 [ C0] [<9000000000343bbc>] ktime_get+0xbc/0xc8 [ C0] [<9000000000354c08>] tick_sched_timer+0x30/0xb0 [ C0] [<90000000003408e0>] __hrtimer_run_queues+0x160/0x378 [ C0] [<9000000000341f14>] hrtimer_interrupt+0x144/0x388 [ C0] [<9000000000228348>] constant_timer_interrupt+0x38/0x48 [ C0] [<90000000002feba4>] __handle_irq_event_percpu+0x64/0x1e8 [ C0] [<90000000002fed48>] handle_irq_event_percpu+0x20/0x80 [ C0] [<9000000000306b9c>] handle_percpu_irq+0x5c/0x98 [ C0] [<90000000002fd4a0>] generic_handle_domain_irq+0x30/0x48 [ C0] [<9000000000d0c7b0>] handle_cpu_irq+0x70/0xa8 [ C0] [<9000000001646b30>] handle_loongarch_irq+0x30/0x48 [ C0] [<9000000001646bc8>] do_vint+0x80/0xe0 [ C0] [<90000000002aea1c>] finish_task_switch.isra.0+0x8c/0x2a8 [ C0] [<900000000164e34c>] __schedule+0x314/0xa48 [ C0] [<900000000164ead8>] schedule+0x58/0xf0 [ C0] [<9000000000294a2c>] worker_thread+0x224/0x498 [ C0] [<900000000029d2f0>] kthread+0xf8/0x108 [ C0] [<9000000000221f28>] ret_from_kernel_thread+0xc/0xa4 [ C0] [ C0] ---[ end trace 0000000000000000 ]--- The root cause is acpi_enable_all_wakeup_gpes() uses a mutex to protect acpi_hw_enable_all_wakeup_gpes(), and acpi_ut_acquire_mutex() may cause a thread switch. Since there is no longer concurrent execution during loongarch_acpi_suspend(), we can call acpi_hw_enable_all_wakeup_gpes() directly in enable_gpe_wakeup(). The solution is similar to commit 22db06337f590d01 ("ACPI: sleep: Avoid breaking S3 wakeup due to might_sleep()").

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Glexia's TakeAutomated analysislow

Security readout for executives and security teams

Plain-English summary

This Linux kernel issue affects LoongArch systems during S3 suspend handling. A wakeup setup path can unexpectedly allow scheduling and leave interrupts enabled, producing kernel warnings. The provided sources describe a correctness and stability bug, not confirmed data theft, privilege escalation, or remote compromise.

Executive priority

Treat this as a targeted stability maintenance issue for LoongArch Linux fleets, not an emergency internet-facing exposure based on provided evidence. Patch through normal kernel maintenance, faster where suspend reliability affects operations.

Technical view

In LoongArch ACPI suspend, enable_gpe_wakeup() called acpi_enable_all_wakeup_gpes(), whose mutex path can sleep via acpi_ut_acquire_mutex(). During loongarch_acpi_suspend(), that can cause a thread switch and interrupt-state mismatch warnings. The fix calls acpi_hw_enable_all_wakeup_gpes() directly because concurrent execution is not expected there.

Likely exposure

Exposure is likely limited to Linux systems running on LoongArch hardware that use ACPI S3 suspend paths. The source bundle lists Linux kernel versions and stable fix references, but exact distribution package impact must be mapped through vendor kernel advisories.

Exploitation context

The bundle does not show CISA KEV listing, active exploitation, exploit availability, CVSS, or a remote attack path. Evidence supports a suspend/resume kernel-state bug with warning output, not a publicly confirmed weaponized vulnerability.

Researcher notes

The key condition is LoongArch ACPI S3 suspend invoking wakeup GPE enablement through a sleeping mutex path. The source states no concurrent execution exists during loongarch_acpi_suspend(), supporting the direct lower-level call as the fix. No exploit primitives are documented.

Mitigation direction

  • Update affected LoongArch Linux kernels using vendor or stable kernel guidance.
  • Confirm fixes corresponding to the referenced kernel.org stable commits.
  • Prioritize systems where S3 suspend is enabled or operationally important.
  • Track distribution advisories for backported kernel package versions.

Validation and detection

  • Inventory Linux hosts running on LoongArch hardware.
  • Check kernel versions against vendor advisories and stable fix commits.
  • Review logs for suspend-related kernel warnings around ACPI wakeup GPE handling.
  • Test S3 suspend and resume after applying vendor kernel updates.
Prepared
Confidence
medium
Sources
6

Public sources used

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.

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Vulnerability profileCVE Program record
Severity
Unknown
CVSS
Not scored
Known Exploited
No
Published
Official CVE source material

CNA and ADP enrichment extracted from CVE v5

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0CVSS vectors
3Timeline events
0ADP providers
5Source links

Vulnerability timeline

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  2. CVE publishedCVE Program

    The CVE record was published.

  3. CVE updatedCVE Program

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Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
LinuxLinux366bb35a8e48198cefcd3484ac6b2374d1347873, 366bb35a8e48198cefcd3484ac6b2374d1347873, 366bb35a8e48198cefcd3484ac6b2374d1347873, 366bb35a8e48198cefcd3484ac6b2374d1347873unaffected
LinuxLinux6.2, 0, 6.6.76, 6.12.13, 6.13.2, 6.14affected
Weakness

CWE details

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