KCSAN: data-race in acpi_ut_track_stack_ptr / acpi_ut_value_exit

Status: moderation: reported on 2026/09/02 02:16
Subsystems: acpica
Labels: race:benign
[Documentation on labels]
Reported-by: syzbot+ab39a309c6535a07ae8b@syzkaller.appspotmail.com
First crash: 1h49m, last: 1h49m
✨ AI Jobs (1)
ID Workflow Result Correct Bug Created Started Finished Revision
7a29da56 assessment-kcsan Benign: ✅ KCSAN: data-race in acpi_ut_track_stack_ptr / acpi_ut_value_exit 2026/09/02 02:16 2026/09/02 02:16 2026/09/02 02:44 587f6b29

Sample crash report:
==================================================================
BUG: KCSAN: data-race in acpi_ut_track_stack_ptr / acpi_ut_value_exit

write to 0xffffffff8961d8c8 of 4 bytes by task 6737 on cpu 1:
 acpi_ut_value_exit+0xe5/0x110 drivers/acpi/acpica/utdebug.c:511
 acpi_ns_build_normalized_path+0x409/0x420 drivers/acpi/acpica/nsnames.c:275
 acpi_ns_handle_to_pathname+0x115/0x1d0 drivers/acpi/acpica/nsnames.c:162
 acpi_rs_create_pci_routing_table+0x41a/0x760 drivers/acpi/acpica/rscreate.c:314
 acpi_rs_get_prt_method_data+0xa3/0x100 drivers/acpi/acpica/rsutils.c:456
 acpi_get_irq_routing_table+0x98/0xe0 drivers/acpi/acpica/rsxface.c:137
 acpi_pci_irq_find_prt_entry+0xb3/0x6e0 drivers/acpi/pci_irq.c:215
 acpi_pci_irq_lookup+0x3e/0x330 drivers/acpi/pci_irq.c:299
 acpi_pci_irq_enable+0x13a/0x3d0 drivers/acpi/pci_irq.c:414
 pcibios_enable_device+0x88/0xa0 arch/x86/pci/common.c:699
 do_pci_enable_device+0x152/0x2d0 drivers/pci/pci.c:2031
 pci_enable_device_flags+0x348/0x3a0 drivers/pci/pci.c:2122
 pci_enable_device+0x1a/0xa0 drivers/pci/pci.c:2155
 i801_probe+0x288/0xbf0 drivers/i2c/busses/i2c-i801.c:1573
 local_pci_probe drivers/pci/pci-driver.c:354 [inline]
 pci_call_probe drivers/pci/pci-driver.c:416 [inline]
 __pci_device_probe drivers/pci/pci-driver.c:478 [inline]
 pci_device_probe+0x2a3/0x530 drivers/pci/pci-driver.c:512
 call_driver_probe drivers/base/dd.c:-1 [inline]
 really_probe+0x1ba/0x600 drivers/base/dd.c:706
 __driver_probe_device+0x14f/0x1c0 drivers/base/dd.c:868
 driver_probe_device+0x37/0x2f0 drivers/base/dd.c:898
 __driver_attach_async_helper+0xb6/0x130 drivers/base/dd.c:1224
 async_run_entry_fn+0x52/0x180 kernel/async.c:129
 process_one_work kernel/workqueue.c:3396 [inline]
 process_scheduled_works+0x56a/0xa50 kernel/workqueue.c:3479
 worker_thread+0x569/0x750 kernel/workqueue.c:3560
 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 0xffffffff8961d8c8 of 4 bytes by task 6723 on cpu 0:
 acpi_ut_track_stack_ptr+0x5f/0xd0 drivers/acpi/acpica/utdebug.c:73
 acpi_ut_push_generic_state+0x19/0x40 drivers/acpi/acpica/utstate.c:30
 acpi_ut_create_update_state_and_push+0x42/0x70 drivers/acpi/acpica/utmisc.c:177
 acpi_ut_update_object_reference+0x1eb/0x560 drivers/acpi/acpica/utdelete.c:563
 acpi_ut_add_reference+0xd5/0xe0 drivers/acpi/acpica/utdelete.c:694
 acpi_ex_resolve_node_to_value+0x760/0x770 drivers/acpi/acpica/exresnte.c:-1
 acpi_ns_evaluate+0x746/0xac0 drivers/acpi/acpica/nseval.c:238
 acpi_ut_evaluate_object+0xa7/0x420 drivers/acpi/acpica/uteval.c:60
 acpi_rs_get_prt_method_data+0x6c/0x100 drivers/acpi/acpica/rsutils.c:446
 acpi_get_irq_routing_table+0x98/0xe0 drivers/acpi/acpica/rsxface.c:137
 acpi_pci_irq_find_prt_entry+0xb3/0x6e0 drivers/acpi/pci_irq.c:215
 acpi_pci_irq_lookup+0x3e/0x330 drivers/acpi/pci_irq.c:299
 acpi_pci_irq_enable+0x13a/0x3d0 drivers/acpi/pci_irq.c:414
 pcibios_enable_device+0x88/0xa0 arch/x86/pci/common.c:699
 do_pci_enable_device+0x152/0x2d0 drivers/pci/pci.c:2031
 pci_enable_device_flags+0x348/0x3a0 drivers/pci/pci.c:2122
 pci_enable_device+0x1a/0xa0 drivers/pci/pci.c:2155
 i801_probe+0x288/0xbf0 drivers/i2c/busses/i2c-i801.c:1573
 local_pci_probe drivers/pci/pci-driver.c:354 [inline]
 pci_call_probe drivers/pci/pci-driver.c:416 [inline]
 __pci_device_probe drivers/pci/pci-driver.c:478 [inline]
 pci_device_probe+0x2a3/0x530 drivers/pci/pci-driver.c:512
 call_driver_probe drivers/base/dd.c:-1 [inline]
 really_probe+0x1ba/0x600 drivers/base/dd.c:706
 __driver_probe_device+0x14f/0x1c0 drivers/base/dd.c:868
 driver_probe_device+0x37/0x2f0 drivers/base/dd.c:898
 __driver_attach_async_helper+0xb6/0x130 drivers/base/dd.c:1224
 async_run_entry_fn+0x52/0x180 kernel/async.c:129
 process_one_work kernel/workqueue.c:3396 [inline]
 process_scheduled_works+0x56a/0xa50 kernel/workqueue.c:3479
 worker_thread+0x569/0x750 kernel/workqueue.c:3560
 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: 0x00000008 -> 0x00000007

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 6723 Comm: kworker/u8:9 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
==================================================================
ACPI: \_SB_.LNKA: Enabled at IRQ 11
i801_smbus 0000:00:05.0: SMBus base address uninitialized, upgrade BIOS

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/09/02 02:16 upstream 89a312991dc6 587f6b29 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in acpi_ut_track_stack_ptr / acpi_ut_value_exit
* Struck through repros no longer work on HEAD.