KCSAN: data-race in acpi_ut_acquire_mutex / acpi_ut_release_mutex

Status: moderation: reported on 2026/08/26 21:13
Subsystems: acpica
Labels: race:benign prio:high
[Documentation on labels]
Reported-by: syzbot+e656aa8af7ad5a5da363@syzkaller.appspotmail.com
First crash: 1d12h, last: 1d12h
✨ AI Jobs (2)
ID Workflow Result Correct Bug Created Started Finished Revision
89b4203c assessment-security DenialOfService: ❌ Exploitable: ❌ FilesystemTrigger: ❌ NetworkTrigger: ❌ PeripheralTrigger: ❌ RemoteTrigger: ❌ Unprivileged: ❌ UserNamespace: ❌ VMGuestTrigger: ✅ VMHostTrigger: ❌ KCSAN: data-race in acpi_ut_acquire_mutex / acpi_ut_release_mutex 2026/08/28 00:58 2026/08/28 00:58 2026/08/28 01:01 bd6de8ec
79403ebc assessment-kcsan Benign: ✅ KCSAN: data-race in acpi_ut_acquire_mutex / acpi_ut_release_mutex 2026/08/27 00:47 2026/08/27 00:47 2026/08/27 01:05 a2b77b9e

Sample crash report:
==================================================================
BUG: KCSAN: data-race in acpi_ut_acquire_mutex / acpi_ut_release_mutex

write to 0xffffffff89618ab8 of 8 bytes by task 3788 on cpu 0:
 acpi_ut_release_mutex+0x209/0x240 drivers/acpi/acpica/utmutex.c:326
 acpi_ns_get_node+0x82/0xc0 drivers/acpi/acpica/nsutils.c:729
 acpi_get_handle+0xfd/0x180 drivers/acpi/acpica/nsxfname.c:98
 acpi_has_method+0x46/0x80 drivers/acpi/utils.c:672
 acpi_pci_set_power_state+0x5d/0x190 drivers/pci/pci-acpi.c:1084
 platform_pci_set_power_state drivers/pci/pci.c:1091 [inline]
 pci_power_up+0x40/0x3b0 drivers/pci/pci.c:1339
 pci_pm_power_up_and_verify_state+0x29/0x130 drivers/pci/pci.c:3186
 pci_pm_default_resume_early drivers/pci/pci-driver.c:614 [inline]
 pci_pm_resume_noirq+0xcb/0x320 drivers/pci/pci-driver.c:1019
 dpm_run_callback+0x53/0x2f0 drivers/base/power/main.c:513
 device_resume_noirq+0x851/0x880 drivers/base/power/main.c:871
 async_resume_noirq+0x2c/0x40 drivers/base/power/main.c:893
 async_run_entry_fn+0x52/0x180 kernel/async.c:129
 process_one_work kernel/workqueue.c:3387 [inline]
 process_scheduled_works+0x56a/0xa50 kernel/workqueue.c:3470
 worker_thread+0x569/0x750 kernel/workqueue.c:3551
 kthread+0x223/0x270 kernel/kthread.c:436
 ret_from_fork+0x146/0x330 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

read to 0xffffffff89618ab8 of 8 bytes by task 3784 on cpu 1:
 acpi_ut_acquire_mutex+0x54/0x4a0 drivers/acpi/acpica/utmutex.c:212
 acpi_ns_get_node+0x46/0xc0 drivers/acpi/acpica/nsutils.c:721
 acpi_get_handle+0xfd/0x180 drivers/acpi/acpica/nsxfname.c:98
 acpi_has_method+0x46/0x80 drivers/acpi/utils.c:672
 acpi_pci_set_power_state+0x5d/0x190 drivers/pci/pci-acpi.c:1084
 platform_pci_set_power_state drivers/pci/pci.c:1091 [inline]
 pci_power_up+0x40/0x3b0 drivers/pci/pci.c:1339
 pci_pm_power_up_and_verify_state+0x29/0x130 drivers/pci/pci.c:3186
 pci_pm_default_resume_early drivers/pci/pci-driver.c:614 [inline]
 pci_pm_resume_noirq+0xcb/0x320 drivers/pci/pci-driver.c:1019
 dpm_run_callback+0x53/0x2f0 drivers/base/power/main.c:513
 device_resume_noirq+0x851/0x880 drivers/base/power/main.c:871
 async_resume_noirq+0x2c/0x40 drivers/base/power/main.c:893
 async_run_entry_fn+0x52/0x180 kernel/async.c:129
 process_one_work kernel/workqueue.c:3387 [inline]
 process_scheduled_works+0x56a/0xa50 kernel/workqueue.c:3470
 worker_thread+0x569/0x750 kernel/workqueue.c:3551
 kthread+0x223/0x270 kernel/kthread.c:436
 ret_from_fork+0x146/0x330 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

value changed: 0xffff8881019b4500 -> 0x0000000000000000

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 3784 Comm: kworker/u8:128 Not tainted syzkaller #0 PREEMPT(lazy) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
Workqueue: async async_run_entry_fn
==================================================================
virtio_scsi virtio0: 1/0/0 default/read/poll queues

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/08/26 21:12 upstream 73ae59e97596 a2b77b9e .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in acpi_ut_acquire_mutex / acpi_ut_release_mutex
* Struck through repros no longer work on HEAD.