syzbot


upstream test error: BUG: soft lockup in led_heartbeat_function

Status: upstream: reported on 2025/12/14 05:55
Subsystems: gpio
[Documentation on labels]
Reported-by: syzbot+6ff4620809efa1842f1a@syzkaller.appspotmail.com
First crash: 4d08h, last: 4d08h
Discussions (1)
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[syzbot] [gpio?] upstream test error: BUG: soft lockup in led_heartbeat_function 0 (1) 2025/12/14 05:55

Sample crash report:
watchdog: BUG: soft lockup - CPU#1 stuck for 430s! [swapper/1:0]
Modules linked in:
CPU: 1 UID: 0 PID: 0 Comm: swapper/1 Not tainted syzkaller #0 PREEMPT 
Hardware name: ARM-Versatile Express
PC is at arch_spin_lock arch/arm/include/asm/spinlock.h:74 [inline]
PC is at do_raw_spin_lock include/linux/spinlock.h:187 [inline]
PC is at __raw_spin_lock include/linux/spinlock_api_smp.h:134 [inline]
PC is at _raw_spin_lock+0x40/0x58 kernel/locking/spinlock.c:154
LR is at __raw_spin_lock include/linux/spinlock_api_smp.h:132 [inline]
LR is at _raw_spin_lock+0x18/0x58 kernel/locking/spinlock.c:154
pc : [<81abbc34>]    lr : [<81abbc0c>]    psr: 80000113
sp : df805d68  ip : df805d68  fp : df805d7c
r10: 81c05450  r9 : 8415b640  r8 : 84046e88
r7 : 8415b768  r6 : 00000000  r5 : 00000001  r4 : 8415b768
r3 : 0000345e  r2 : 0000345f  r1 : 00000000  r0 : 00000001
Flags: Nzcv  IRQs on  FIQs on  Mode SVC_32  ISA ARM  Segment none
Control: 30c5387d  Table: 85216dc0  DAC: 00000000
Call trace: frame pointer underflow
[<81abbbf4>] (_raw_spin_lock) from [<809c77ac>] (class_raw_spinlock_constructor include/linux/spinlock.h:535 [inline])
[<81abbbf4>] (_raw_spin_lock) from [<809c77ac>] (gpio_mmio_set+0x44/0x80 drivers/gpio/gpio-mmio.c:234)
 r5:00000001 r4:8415b640
[<809c7768>] (gpio_mmio_set) from [<809b7f68>] (gpiochip_set+0x1c/0x44 drivers/gpio/gpiolib.c:2919)
 r7:00000000 r6:00000000 r5:00000000 r4:840e1840
[<809b7f4c>] (gpiochip_set) from [<809ba830>] (gpiod_set_raw_value_commit+0x78/0x218 drivers/gpio/gpiolib.c:3662)
[<809ba7b8>] (gpiod_set_raw_value_commit) from [<809bc0d0>] (gpiod_set_value_nocheck+0x44/0x58 drivers/gpio/gpiolib.c:3881)
 r10:81c05450 r9:df805ebc r8:00000102 r7:ffffa9af r6:00000035 r5:00000000
 r4:840e1840
[<809bc08c>] (gpiod_set_value_nocheck) from [<809bc120>] (gpiod_set_value+0x3c/0x88 drivers/gpio/gpiolib.c:3903)
[<809bc0e4>] (gpiod_set_value) from [<809cc8bc>] (gpio_led_set+0x5c/0x60 drivers/leds/leds-gpio.c:57)
 r5:83fc1044 r4:83fc1044
[<809cc860>] (gpio_led_set) from [<809ca154>] (__led_set_brightness drivers/leds/led-core.c:52 [inline])
[<809cc860>] (gpio_led_set) from [<809ca154>] (led_set_brightness_nopm drivers/leds/led-core.c:335 [inline])
[<809cc860>] (gpio_led_set) from [<809ca154>] (led_set_brightness_nosleep+0x38/0x44 drivers/leds/led-core.c:369)
 r5:83fc1044 r4:84b62c4c
[<809ca11c>] (led_set_brightness_nosleep) from [<809cd1b8>] (led_heartbeat_function+0x84/0x144 drivers/leds/trigger/ledtrig-heartbeat.c:90)
[<809cd134>] (led_heartbeat_function) from [<80326f70>] (call_timer_fn+0x30/0x220 kernel/time/timer.c:1748)
 r7:ffffa9af r6:809cd134 r5:84b62c4c r4:83216000
[<80326f40>] (call_timer_fn) from [<80327424>] (expire_timers kernel/time/timer.c:1799 [inline])
[<80326f40>] (call_timer_fn) from [<80327424>] (__run_timers+0x2c4/0x3f8 kernel/time/timer.c:2373)
 r9:df805ebc r8:ffffa9af r7:00000000 r6:809cd134 r5:dddd9f00 r4:84b62c4c
[<80327160>] (__run_timers) from [<803275c0>] (__run_timer_base kernel/time/timer.c:2385 [inline])
[<80327160>] (__run_timers) from [<803275c0>] (__run_timer_base kernel/time/timer.c:2377 [inline])
[<80327160>] (__run_timers) from [<803275c0>] (run_timer_base+0x68/0x78 kernel/time/timer.c:2394)
 r10:83216000 r9:82804d80 r8:00000102 r7:00000001 r6:00000082 r5:00000002
 r4:dddd9f00
[<80327558>] (run_timer_base) from [<803275ec>] (run_timer_softirq+0x1c/0x34 kernel/time/timer.c:2404)
 r4:82804084
[<803275d0>] (run_timer_softirq) from [<8025b55c>] (handle_softirqs+0x140/0x458 kernel/softirq.c:622)
[<8025b41c>] (handle_softirqs) from [<8025b9d0>] (__do_softirq kernel/softirq.c:656 [inline])
[<8025b41c>] (handle_softirqs) from [<8025b9d0>] (invoke_softirq kernel/softirq.c:496 [inline])
[<8025b41c>] (handle_softirqs) from [<8025b9d0>] (__irq_exit_rcu+0x110/0x1d0 kernel/softirq.c:723)
 r10:00000000 r9:83216000 r8:00000000 r7:df865e08 r6:82443ff8 r5:8247f12c
 r4:83216000
[<8025b8c0>] (__irq_exit_rcu) from [<8025bd48>] (irq_exit+0x10/0x18 kernel/softirq.c:751)
 r5:8247f12c r4:826c3a9c
[<8025bd38>] (irq_exit) from [<81aad6a4>] (generic_handle_arch_irq+0x7c/0x80 kernel/irq/handle.c:295)
[<81aad628>] (generic_handle_arch_irq) from [<81a7d654>] (call_with_stack+0x1c/0x20 arch/arm/lib/call_with_stack.S:40)
 r9:83216000 r8:84046e88 r7:df865e3c r6:ffffffff r5:60000013 r4:809c7fac
[<81a7d638>] (call_with_stack) from [<80200bec>] (__irq_svc+0x8c/0xbc arch/arm/kernel/entry-armv.S:228)
Exception stack(0xdf865e08 to 0xdf865e50)
5e00:                   e0299008 0000000d 0000345e 00000000 e0299008 0000000d
5e20: 00000001 8415b768 84046e88 8415b640 00000000 df865e6c df865e58 df865e58
5e40: 809c7fa8 809c7fac 60000013 ffffffff
[<809c7f8c>] (gpio_mmio_write32) from [<809c77cc>] (gpio_mmio_set+0x64/0x80 drivers/gpio/gpio-mmio.c:241)
 r5:00000008 r4:8415b640
[<809c7768>] (gpio_mmio_set) from [<809b7f68>] (gpiochip_set+0x1c/0x44 drivers/gpio/gpiolib.c:2919)
 r7:00000001 r6:00000000 r5:00000003 r4:840e187c
[<809b7f4c>] (gpiochip_set) from [<809ba830>] (gpiod_set_raw_value_commit+0x78/0x218 drivers/gpio/gpiolib.c:3662)
[<809ba7b8>] (gpiod_set_raw_value_commit) from [<809bc0d0>] (gpiod_set_value_nocheck+0x44/0x58 drivers/gpio/gpiolib.c:3881)
 r10:00000000 r9:00000000 r8:00000001 r7:ddde24c0 r6:83e7a298 r5:00000001
 r4:840e187c
[<809bc08c>] (gpiod_set_value_nocheck) from [<809bc120>] (gpiod_set_value+0x3c/0x88 drivers/gpio/gpiolib.c:3903)
[<809bc0e4>] (gpiod_set_value) from [<809cc8bc>] (gpio_led_set+0x5c/0x60 drivers/leds/leds-gpio.c:57)
 r5:000000ff r4:83fc1314
[<809cc860>] (gpio_led_set) from [<809ca1e4>] (__led_set_brightness drivers/leds/led-core.c:52 [inline])
[<809cc860>] (gpio_led_set) from [<809ca1e4>] (led_set_brightness_nopm drivers/leds/led-core.c:335 [inline])
[<809cc860>] (gpio_led_set) from [<809ca1e4>] (led_set_brightness_nosleep drivers/leds/led-core.c:369 [inline])
[<809cc860>] (gpio_led_set) from [<809ca1e4>] (led_set_brightness+0x84/0x90 drivers/leds/led-core.c:328)
 r5:000000ff r4:83fc1314
[<809ca160>] (led_set_brightness) from [<809cbd64>] (led_trigger_event drivers/leds/led-triggers.c:420 [inline])
[<809ca160>] (led_set_brightness) from [<809cbd64>] (led_trigger_event+0x40/0x58 drivers/leds/led-triggers.c:408)
 r5:000000ff r4:83fc1314
[<809cbd24>] (led_trigger_event) from [<809cd3c0>] (ledtrig_cpu+0xac/0xf4 drivers/leds/trigger/ledtrig-cpu.c:86)
 r7:ddde24c0 r6:00000002 r5:82b15cd8 r4:000001fd
[<809cd314>] (ledtrig_cpu) from [<80227a38>] (arch_cpu_idle_exit+0x14/0x18 arch/arm/kernel/process.c:98)
 r9:00000000 r8:00000001 r7:8280c710 r6:83216000 r5:8280c6d0 r4:00000001
[<80227a24>] (arch_cpu_idle_exit) from [<802b158c>] (do_idle+0x5c/0x2d8 kernel/sched/idle.c:334)
[<802b1530>] (do_idle) from [<802b1b38>] (cpu_startup_entry+0x30/0x34 kernel/sched/idle.c:430)
 r10:00000000 r9:414fc0f0 r8:80003000 r7:82a7b4a4 r6:83216000 r5:00000001
 r4:00000092
[<802b1b08>] (cpu_startup_entry) from [<8022f360>] (secondary_start_kernel+0x128/0x194 arch/arm/kernel/smp.c:478)
[<8022f238>] (secondary_start_kernel) from [<80220094>] (__enable_mmu+0x0/0xc arch/arm/kernel/head.S:446)
 r7:82a7b4a4 r6:30c0387d r5:00000000 r4:830b7bc0
Sending NMI from CPU 1 to CPUs 0:

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/12/10 05:46 upstream c9b47175e913 fc20f974 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu2-arm32 upstream test error: BUG: soft lockup in led_heartbeat_function
* Struck through repros no longer work on HEAD.