kernel panic: KCSAN: panic_on_warn set ...

Status: moderation: reported on 2026/08/04 16:57
Subsystems: kasan
[Documentation on labels]
Reported-by: syzbot+2c7d8efa6ec3b387862c@syzkaller.appspotmail.com
First crash: 2d08h, last: 2d07h

Sample crash report:
Kernel panic - not syncing: KCSAN: panic_on_warn set ...
CPU: 0 UID: 0 PID: 3665 Comm: kworker/u8:142 Tainted: G        W           syzkaller #0 PREEMPT(lazy) 
Tainted: [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
Workqueue: async async_run_entry_fn
Call Trace:
 <TASK>
 __dump_stack+0x1d/0x30 lib/dump_stack.c:94
 dump_stack_lvl+0x26/0xd0 lib/dump_stack.c:120
 dump_stack+0x15/0x1b lib/dump_stack.c:129
 vpanic+0x522/0x8e0 kernel/panic.c:651
 panic+0x67/0x70 kernel/panic.c:788
 check_panic_on_warn+0x8b/0xb0 kernel/panic.c:525
 print_report+0x533/0x560 kernel/kcsan/report.c:499
 kcsan_report_known_origin+0x13e/0x1a0 kernel/kcsan/report.c:697
 kcsan_setup_watchpoint+0x396/0x450 kernel/kcsan/core.c:678
 desc_read kernel/printk/printk_ringbuffer.c:496 [inline]
 desc_push_tail kernel/printk/printk_ringbuffer.c:792 [inline]
 desc_reserve kernel/printk/printk_ringbuffer.c:938 [inline]
 prb_reserve+0x21a/0xaf0 kernel/printk/printk_ringbuffer.c:1677
 vprintk_store+0x54a/0x910 kernel/printk/printk.c:2354
 vprintk_emit+0x1a4/0x600 kernel/printk/printk.c:2455
 vprintk_default+0x26/0x30 kernel/printk/printk.c:2494
 vprintk+0x1d/0x30 kernel/printk/printk_safe.c:82
 _printk+0x79/0xa0 kernel/printk/printk.c:2504
 acpi_os_vprintf include/linux/printk.h:-1 [inline]
 acpi_os_printf+0x11c/0x200 drivers/acpi/osl.c:153
 acpi_debug_print+0x150/0x200 drivers/acpi/acpica/utdebug.c:171
 acpi_ut_trace+0x141/0x180 drivers/acpi/acpica/utdebug.c:274
 acpi_ns_search_one_scope+0x5f/0x3f0 drivers/acpi/acpica/nssearch.c:66
 acpi_ns_search_and_enter+0xc3/0x860 drivers/acpi/acpica/nssearch.c:286
 acpi_ns_lookup+0xbd8/0x1070 drivers/acpi/acpica/nsaccess.c:589
 acpi_ns_get_node_unlocked+0x143/0x2d0 drivers/acpi/acpica/nsutils.c:677
 acpi_ns_get_node+0x76/0xc0 drivers/acpi/acpica/nsutils.c:726
 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_resume_noirq+0xcb/0x320 drivers/pci/pci-driver.c:996
 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
 </TASK>
Dumping ftrace buffer:
   (ftrace buffer empty)
Kernel Offset: disabled
Rebooting in 86400 seconds..

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/08/04 17:51 upstream 848acc8ffe1b d4abbeac .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce kernel panic: KCSAN: panic_on_warn set ...
2026/08/04 16:57 upstream 848acc8ffe1b d4abbeac .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce kernel panic: KCSAN: panic_on_warn set ...
* Struck through repros no longer work on HEAD.