Linux Kernel up to 6.6.75/6.12.12/6.13.1 Function Call timekeeping.c enable_gpe_wakeup state issue

Summaryinfo

A vulnerability has been found in Linux Kernel up to 6.6.75/6.12.12/6.13.1 and classified as problematic. Affected by this issue is the function enable_gpe_wakeup of the file kernel/time/timekeeping.c of the component Function Call Handler. The manipulation leads to state issue. This vulnerability is documented as CVE-2025-21803. There is not any exploit available. The affected component should be upgraded.

Detailsinfo

A vulnerability was found in Linux Kernel up to 6.6.75/6.12.12/6.13.1. It has been rated as problematic. This issue affects the function enable_gpe_wakeup of the file kernel/time/timekeeping.c of the component Function Call Handler. The manipulation with an unknown input leads to a state issue vulnerability. Using CWE to declare the problem leads to CWE-371. The impact remains unknown. The summary by CVE is:

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()").

The advisory is shared at git.kernel.org. The identification of this vulnerability is CVE-2025-21803 since 12/29/2024. The exploitation is known to be difficult. Technical details are known, but no exploit is available. The price for an exploit might be around USD $0-$5k at the moment (estimation calculated on 02/16/2026).

The vulnerability scanner Nessus provides a plugin with the ID 230752 (Linux Distros Unpatched Vulnerability : CVE-2025-21803), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 6.6.76, 6.12.13, 6.13.2 or 6.14-rc1 eliminates this vulnerability. Applying the patch d49ab6857d98266010f3446c9c2063014db5b654/194d26a5a43c26dc98a9b4e2c1d521dcb84dd1bf/8682a71a7f6de7c683f31b4334b04e19685a05f9/26c0a2d93af55d30a46d5f45d3e9c42cde730168 is able to eliminate this problem. The bugfix is ready for download at git.kernel.org. The best possible mitigation is suggested to be upgrading to the latest version.

The vulnerability is also documented in the databases at Tenable (230752) and CERT Bund (WID-SEC-2025-0461). Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Affected

• Google Container-Optimized OS
• Debian Linux
• Amazon Linux 2
• Red Hat Enterprise Linux
• Ubuntu Linux
• SUSE Linux
• Oracle Linux
• SUSE openSUSE
• Open Source Linux Kernel
• Dell Secure Connect Gateway

Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

Version

• 6.6.0
• 6.6.1
• 6.6.2
• 6.6.3
• 6.6.4
• 6.6.5
• 6.6.6
• 6.6.7
• 6.6.8
• 6.6.9
• 6.6.10
• 6.6.11
• 6.6.12
• 6.6.13
• 6.6.14
• 6.6.15
• 6.6.16
• 6.6.17
• 6.6.18
• 6.6.19
• 6.6.20
• 6.6.21
• 6.6.22
• 6.6.23
• 6.6.24
• 6.6.25
• 6.6.26
• 6.6.27
• 6.6.28
• 6.6.29
• 6.6.30
• 6.6.31
• 6.6.32
• 6.6.33
• 6.6.34
• 6.6.35
• 6.6.36
• 6.6.37
• 6.6.38
• 6.6.39
• 6.6.40
• 6.6.41
• 6.6.42
• 6.6.43
• 6.6.44
• 6.6.45
• 6.6.46
• 6.6.47
• 6.6.48
• 6.6.49
• 6.6.50
• 6.6.51
• 6.6.52
• 6.6.53
• 6.6.54
• 6.6.55
• 6.6.56
• 6.6.57
• 6.6.58
• 6.6.59
• 6.6.60
• 6.6.61
• 6.6.62
• 6.6.63
• 6.6.64
• 6.6.65
• 6.6.66
• 6.6.67
• 6.6.68
• 6.6.69
• 6.6.70
• 6.6.71
• 6.6.72
• 6.6.73
• 6.6.74
• 6.6.75
• 6.12.0
• 6.12.1
• 6.12.2
• 6.12.3
• 6.12.4
• 6.12.5
• 6.12.6
• 6.12.7
• 6.12.8
• 6.12.9
• 6.12.10
• 6.12.11
• 6.12.12
• 6.13.0
• 6.13.1

License

• open-source

Website

• Vendor: https://www.kernel.org/

CPE 2.3info

• 🔍
• 🔍
• 🔍

CPE 2.2info

• 🔍
• 🔍
• 🔍

CVSSv4info

CVSSv3info

CVSSv2info

Exploitinginfo

Threat Intelligenceinfo

Countermeasuresinfo

Timelineinfo

Sourcesinfo

Entryinfo

Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Discussion