[moderation] [acpica?] KCSAN: data-race in number / vsnprintf

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Aug 4, 2026, 11:09:23 AM (yesterday) Aug 4
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Hello,

syzbot found the following issue on:

HEAD commit: 848acc8ffe1b Merge tag 'fsverity-for-linus' of git://git.k..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=140dbe32580000
kernel config: https://syzkaller.appspot.com/x/.config?x=84b3039e8461eef5
dashboard link: https://syzkaller.appspot.com/bug?extid=5a88382d85493a9fee22
compiler: Debian clang version 22.1.8 (++20260613092233+e80beda6e255-1~exp1~20260613092250.77), Debian LLD 22.1.8
CC: [acpica...@lists.linux.dev le...@kernel.org linux...@vger.kernel.org linux-...@vger.kernel.org raf...@kernel.org robert...@intel.com saket....@intel.com]

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/d1a0ae21bd78/disk-848acc8f.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/9be505d18eb6/vmlinux-848acc8f.xz
kernel image: https://storage.googleapis.com/syzbot-assets/8ab6a3838bc0/bzImage-848acc8f.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+5a8838...@syzkaller.appspotmail.com

osl-1334 os_signal_semaphore : Signaling semaphore[ffff8881000c3390|1]
==================================================================
BUG: KCSAN: data-race in number / vsnprintf

write to 0xffffffff89405bc0 of 30 bytes by task 3755 on cpu 1:
vsnprintf+0x2c0/0x8c0 lib/vsprintf.c:2896
vsprintf+0x2a/0x40 lib/vsprintf.c:3090
acpi_os_vprintf drivers/acpi/osl.c:162 [inline]
acpi_os_printf+0x87/0x200 drivers/acpi/osl.c:153
acpi_debug_print+0x113/0x200 drivers/acpi/acpica/utdebug.c:158
acpi_os_wait_semaphore+0x29e/0x2b0 drivers/acpi/osl.c:1310
acpi_ut_acquire_mutex+0x242/0x4a0 drivers/acpi/acpica/utmutex.c:241
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:1068 [inline]
pci_power_up+0x40/0x3b0 drivers/pci/pci.c:1306
pci_pm_power_up_and_verify_state+0x29/0x130 drivers/pci/pci.c:3153
pci_pm_default_resume_early drivers/pci/pci-driver.c:591 [inline]
pci_pm_restore_noirq+0x53/0x1b0 drivers/pci/pci-driver.c:1259
dpm_run_callback+0x53/0x2f0 drivers/base/power/main.c:510
device_resume_noirq+0x851/0x880 drivers/base/power/main.c:857
async_resume_noirq+0x2c/0x40 drivers/base/power/main.c:879
async_run_entry_fn+0x52/0x180 kernel/async.c:129
process_one_work kernel/workqueue.c:3322 [inline]
process_scheduled_works+0x4d4/0x9a0 kernel/workqueue.c:3405
worker_thread+0x569/0x750 kernel/workqueue.c:3486
kthread+0x221/0x270 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

write to 0xffffffff89405bca of 1 bytes by task 3757 on cpu 0:
number+0x5c2/0xb80 lib/vsprintf.c:553
vsnprintf+0x68f/0x8c0 lib/vsprintf.c:2909
vsprintf+0x2a/0x40 lib/vsprintf.c:3090
acpi_os_vprintf drivers/acpi/osl.c:162 [inline]
acpi_os_printf+0x87/0x200 drivers/acpi/osl.c:153
acpi_debug_print+0x150/0x200 drivers/acpi/acpica/utdebug.c:171
acpi_ut_status_exit+0xc1/0x120 drivers/acpi/acpica/utdebug.c:-1
acpi_ns_get_node+0xa2/0xc0 drivers/acpi/acpica/nsutils.c:-1
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:1068 [inline]
pci_power_up+0x40/0x3b0 drivers/pci/pci.c:1306
pci_pm_power_up_and_verify_state+0x29/0x130 drivers/pci/pci.c:3153
pci_pm_default_resume_early drivers/pci/pci-driver.c:591 [inline]
pci_pm_restore_noirq+0x53/0x1b0 drivers/pci/pci-driver.c:1259
dpm_run_callback+0x53/0x2f0 drivers/base/power/main.c:510
device_resume_noirq+0x851/0x880 drivers/base/power/main.c:857
async_resume_noirq+0x2c/0x40 drivers/base/power/main.c:879
async_run_entry_fn+0x52/0x180 kernel/async.c:129
process_one_work kernel/workqueue.c:3322 [inline]
process_scheduled_works+0x4d4/0x9a0 kernel/workqueue.c:3405
worker_thread+0x569/0x750 kernel/workqueue.c:3486
kthread+0x221/0x270 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: 0x73 -> 0x65

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 3757 Comm: kworker/u8:46 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

==================================================================


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