| 0/0 |
2026/03/08 08:11 |
flow |
repro |
6m
Results: map[ReproOpts:{"repeat":true,"procs":1,"sandbox":"none"} ReproSyz:r0 = openat(0xffffffffffffff9c, &(0x7f0000000000)='/sys/class/leds/v2m:green:user1/trigger\x00', 0x2, 0x0)
write(r0, &(0x7f0000000080)='heartbeat', 0x9)
r1 = openat(0xffffffffffffff9c, &(0x7f0000000100)='/sys/class/leds/v2m:green:user2/trigger\x00', 0x2, 0x0)
write(r1, &(0x7f0000000180)='cpu', 0x3)
r2 = openat(0xffffffffffffff9c, &(0x7f0000000200)='/sys/class/leds/v2m:green:user3/trigger\x00', 0x2, 0x0)
write(r2, &(0x7f0000000280)='heartbeat', 0x9)
r3 = openat(0xffffffffffffff9c, &(0x7f0000000300)='/sys/class/leds/v2m:green:user4/trigger\x00', 0x2, 0x0)
write(r3, &(0x7f0000000380)='cpu', 0x3)
r4 = openat(0xffffffffffffff9c, &(0x7f0000000400)='/sys/class/leds/v2m:green:user5/trigger\x00', 0x2, 0x0)
write(r4, &(0x7f0000000480)='heartbeat', 0x9)
r5 = openat(0xffffffffffffff9c, &(0x7f0000000500)='/sys/class/leds/v2m:green:user6/trigger\x00', 0x2, 0x0)
write(r5, &(0x7f0000000580)='cpu', 0x3)
nanosleep(&(0x7f0000000600)={0x0, 0x2710}, 0x0)
SyzkallerCommit:31e9c887f7dc24e04b3ca70d0d54fc34141844b0]
|
| 1/1 |
2026/03/08 08:11 |
action |
provide-var |
0m
Results: map[DescriptionFiles:[acpi_thermal_rel.txt aio.txt auto.txt binfmt.txt bpf.txt bpf_prog.txt bpf_trace.txt cgroup.txt damon.txt dev_ashmem.txt dev_bifrost.txt dev_binder.txt dev_binderfs.txt dev_block.txt dev_bsg.txt dev_bus_usb.txt dev_camx.txt dev_cdrom.txt dev_cec.txt dev_char_usb.txt dev_comedi.txt dev_dma_heap.txt dev_dri.txt dev_dsp.txt dev_dvb_demux.txt dev_dvb_dvr.txt dev_dvb_frontend.txt dev_fb.txt dev_floppy.txt dev_hidraw.txt dev_i2c.txt dev_i915.txt dev_img_rogue.txt dev_infiniband_rdma.txt dev_infiniband_rdma_cm.txt dev_input.txt dev_iommu.txt dev_kvm.txt dev_kvm_amd64.txt dev_kvm_arm64.txt dev_kvm_extra.txt dev_kvm_riscv64.txt dev_loop.txt dev_mali.txt dev_media.txt dev_msm.txt dev_msr.txt dev_nbd.txt dev_net_tun.txt dev_panthor.txt dev_ppp.txt dev_ptmx.txt dev_ptp.txt dev_qat_adf_ctl.txt dev_qrtr_tun.txt dev_random.txt dev_rfkill.txt dev_rtc.txt dev_sequencer.txt dev_sg.txt dev_snapshot.txt dev_snd_control.txt dev_snd_hw.txt dev_snd_midi.txt dev_snd_pcm.txt dev_snd_seq.txt dev_snd_timer.txt dev_sr.txt dev_sw_sync.txt dev_tlk_device.txt dev_trusty.txt dev_udmabuf.txt dev_uhid.txt dev_uinput.txt dev_usb_hiddev.txt dev_usbmon.txt dev_userio.txt dev_vfio.txt dev_vga_arbiter.txt dev_vhci.txt dev_video4linux.txt dev_video4linux_vim2m.txt dev_virtual_nci.txt dev_vtpm.txt fanotify.txt filesystem.txt fs_9p.txt fs_fuse.txt fs_incfs.txt fs_ioctl.txt fs_ioctl_autofs.txt fs_ioctl_btrfs.txt fs_ioctl_ext4.txt fs_ioctl_f2fs.txt fs_ioctl_fat.txt fs_ioctl_fscrypt.txt fs_ioctl_fsverity.txt fs_ioctl_xfs.txt futex.txt hafnium.txt inotify.txt io_uring.txt ipc.txt key.txt kfuzztest.txt l2cap.txt landlock.txt lsm.txt namespaces.txt net_80211.txt netfilter.txt netfilter_arp.txt netfilter_bridge.txt netfilter_ipv4.txt netfilter_ipv6.txt netfilter_ipvs.txt netfilter_targets.txt pagemap_ioctl.txt perf.txt prctl.txt quotactl.txt seccomp.txt security_apparmor.txt security_selinux.txt security_smack.txt socket.txt socket_alg.txt socket_ax25.txt socket_bluetooth.txt socket_caif.txt socket_can.txt socket_ieee802154.txt socket_inet.txt socket_inet6.txt socket_inet_dccp.txt socket_inet_icmp.txt socket_inet_igmp.txt socket_inet_l2tp.txt socket_inet_sctp.txt socket_inet_tcp.txt socket_inet_udp.txt socket_ip_tunnel.txt socket_isdn.txt socket_kcm.txt socket_key.txt socket_llc.txt socket_netlink.txt socket_netlink_audit.txt socket_netlink_crypto.txt socket_netlink_generic.txt socket_netlink_generic_80211.txt socket_netlink_generic_batadv.txt socket_netlink_generic_devlink.txt socket_netlink_generic_ethtool.txt socket_netlink_generic_fou.txt socket_netlink_generic_gtp.txt socket_netlink_generic_mptcp.txt socket_netlink_generic_net_dm.txt socket_netlink_generic_netlabel.txt socket_netlink_generic_nfc.txt socket_netlink_generic_seg6.txt socket_netlink_generic_smc.txt socket_netlink_generic_team.txt socket_netlink_generic_wireguard.txt socket_netlink_netfilter.txt socket_netlink_netfilter_acct.txt socket_netlink_netfilter_conntrack.txt socket_netlink_netfilter_conntrack_exp.txt socket_netlink_netfilter_conntrack_helper.txt socket_netlink_netfilter_ipset.txt socket_netlink_netfilter_log.txt socket_netlink_netfilter_nft_compat.txt socket_netlink_netfilter_nftables.txt socket_netlink_netfilter_osf.txt socket_netlink_netfilter_queue.txt socket_netlink_netfilter_timeout.txt socket_netlink_rdma.txt socket_netlink_route.txt socket_netlink_route_sched.txt socket_netlink_route_sched_retired.txt socket_netlink_sock_diag.txt socket_netlink_xfrm.txt socket_netrom.txt socket_nfc.txt socket_nvme_of_tcp.txt socket_packet.txt socket_phonet.txt socket_pppox.txt socket_qipcrtr.txt socket_rds.txt socket_rose.txt socket_rxrpc.txt socket_tipc.txt socket_tipc_netlink.txt socket_unix.txt socket_vnet.txt socket_x25.txt socket_xdp.txt sys.txt uffd.txt usbip.txt vmw_vmci.txt vnet.txt vnet_mptcp.txt vusb.txt watch_queue.txt xattr.txt] SyzkallerCommit:31e9c887f7dc24e04b3ca70d0d54fc34141844b0]
|
| 2/1 |
2026/03/08 08:11 |
action |
kernel-checkouter |
0m
Results: map[KernelSrc:/usr/local/google/home/dvyukov/syzkaller/agent/workdir/cache/src/444acd82f070568c13b999c14c9fe1556e0eb91e]
|
| 3/1 |
2026/03/08 08:12 |
action |
kernel-builder |
2m
Results: map[KernelObj:/usr/local/google/home/dvyukov/syzkaller/agent/workdir/cache/build/28e781dbc268beafc21d4833348bcea8ac1da8a2]
|
| 4/1 |
2026/03/08 08:14 |
agent |
crash-repro-finder |
2m
Model:
Results: map[ReproOpts:{"repeat":true,"procs":1,"sandbox":"none"}]
Instruction:
You are an expert in linux kernel fuzzing. Your goal is to write a syzkaller program to trigger a specific bug.
Print only the syz program that could be executed directly, without backticks.
Use set-results tool to provide results of the analysis.
It must be called exactly once before the final reply.
Ignore results of this tool.
Prompt:
Bug Title: upstream test error: BUG: soft lockup in led_heartbeat_function
Original 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:
The list of existing description files:
acpi_thermal_rel.txt
aio.txt
auto.txt
binfmt.txt
bpf.txt
bpf_prog.txt
bpf_trace.txt
cgroup.txt
damon.txt
dev_ashmem.txt
dev_bifrost.txt
dev_binder.txt
dev_binderfs.txt
dev_block.txt
dev_bsg.txt
dev_bus_usb.txt
dev_camx.txt
dev_cdrom.txt
dev_cec.txt
dev_char_usb.txt
dev_comedi.txt
dev_dma_heap.txt
dev_dri.txt
dev_dsp.txt
dev_dvb_demux.txt
dev_dvb_dvr.txt
dev_dvb_frontend.txt
dev_fb.txt
dev_floppy.txt
dev_hidraw.txt
dev_i2c.txt
dev_i915.txt
dev_img_rogue.txt
dev_infiniband_rdma.txt
dev_infiniband_rdma_cm.txt
dev_input.txt
dev_iommu.txt
dev_kvm.txt
dev_kvm_amd64.txt
dev_kvm_arm64.txt
dev_kvm_extra.txt
dev_kvm_riscv64.txt
dev_loop.txt
dev_mali.txt
dev_media.txt
dev_msm.txt
dev_msr.txt
dev_nbd.txt
dev_net_tun.txt
dev_panthor.txt
dev_ppp.txt
dev_ptmx.txt
dev_ptp.txt
dev_qat_adf_ctl.txt
dev_qrtr_tun.txt
dev_random.txt
dev_rfkill.txt
dev_rtc.txt
dev_sequencer.txt
dev_sg.txt
dev_snapshot.txt
dev_snd_control.txt
dev_snd_hw.txt
dev_snd_midi.txt
dev_snd_pcm.txt
dev_snd_seq.txt
dev_snd_timer.txt
dev_sr.txt
dev_sw_sync.txt
dev_tlk_device.txt
dev_trusty.txt
dev_udmabuf.txt
dev_uhid.txt
dev_uinput.txt
dev_usb_hiddev.txt
dev_usbmon.txt
dev_userio.txt
dev_vfio.txt
dev_vga_arbiter.txt
dev_vhci.txt
dev_video4linux.txt
dev_video4linux_vim2m.txt
dev_virtual_nci.txt
dev_vtpm.txt
fanotify.txt
filesystem.txt
fs_9p.txt
fs_fuse.txt
fs_incfs.txt
fs_ioctl.txt
fs_ioctl_autofs.txt
fs_ioctl_btrfs.txt
fs_ioctl_ext4.txt
fs_ioctl_f2fs.txt
fs_ioctl_fat.txt
fs_ioctl_fscrypt.txt
fs_ioctl_fsverity.txt
fs_ioctl_xfs.txt
futex.txt
hafnium.txt
inotify.txt
io_uring.txt
ipc.txt
key.txt
kfuzztest.txt
l2cap.txt
landlock.txt
lsm.txt
namespaces.txt
net_80211.txt
netfilter.txt
netfilter_arp.txt
netfilter_bridge.txt
netfilter_ipv4.txt
netfilter_ipv6.txt
netfilter_ipvs.txt
netfilter_targets.txt
pagemap_ioctl.txt
perf.txt
prctl.txt
quotactl.txt
seccomp.txt
security_apparmor.txt
security_selinux.txt
security_smack.txt
socket.txt
socket_alg.txt
socket_ax25.txt
socket_bluetooth.txt
socket_caif.txt
socket_can.txt
socket_ieee802154.txt
socket_inet.txt
socket_inet6.txt
socket_inet_dccp.txt
socket_inet_icmp.txt
socket_inet_igmp.txt
socket_inet_l2tp.txt
socket_inet_sctp.txt
socket_inet_tcp.txt
socket_inet_udp.txt
socket_ip_tunnel.txt
socket_isdn.txt
socket_kcm.txt
socket_key.txt
socket_llc.txt
socket_netlink.txt
socket_netlink_audit.txt
socket_netlink_crypto.txt
socket_netlink_generic.txt
socket_netlink_generic_80211.txt
socket_netlink_generic_batadv.txt
socket_netlink_generic_devlink.txt
socket_netlink_generic_ethtool.txt
socket_netlink_generic_fou.txt
socket_netlink_generic_gtp.txt
socket_netlink_generic_mptcp.txt
socket_netlink_generic_net_dm.txt
socket_netlink_generic_netlabel.txt
socket_netlink_generic_nfc.txt
socket_netlink_generic_seg6.txt
socket_netlink_generic_smc.txt
socket_netlink_generic_team.txt
socket_netlink_generic_wireguard.txt
socket_netlink_netfilter.txt
socket_netlink_netfilter_acct.txt
socket_netlink_netfilter_conntrack.txt
socket_netlink_netfilter_conntrack_exp.txt
socket_netlink_netfilter_conntrack_helper.txt
socket_netlink_netfilter_ipset.txt
socket_netlink_netfilter_log.txt
socket_netlink_netfilter_nft_compat.txt
socket_netlink_netfilter_nftables.txt
socket_netlink_netfilter_osf.txt
socket_netlink_netfilter_queue.txt
socket_netlink_netfilter_timeout.txt
socket_netlink_rdma.txt
socket_netlink_route.txt
socket_netlink_route_sched.txt
socket_netlink_route_sched_retired.txt
socket_netlink_sock_diag.txt
socket_netlink_xfrm.txt
socket_netrom.txt
socket_nfc.txt
socket_nvme_of_tcp.txt
socket_packet.txt
socket_phonet.txt
socket_pppox.txt
socket_qipcrtr.txt
socket_rds.txt
socket_rose.txt
socket_rxrpc.txt
socket_tipc.txt
socket_tipc_netlink.txt
socket_unix.txt
socket_vnet.txt
socket_x25.txt
socket_xdp.txt
sys.txt
uffd.txt
usbip.txt
vmw_vmci.txt
vnet.txt
vnet_mptcp.txt
vusb.txt
watch_queue.txt
xattr.txt
Reply: r0 = openat(0xffffffffffffff9c, &(0x7f0000000000)='/sys/class/leds/v2m:green:user1/trigger\x00', 0x2, 0x0)
write(r0, &(0x7f0000000080)='heartbeat', 0x9)
r1 = openat(0xffffffffffffff9c, &(0x7f0000000100)='/sys/class/leds/v2m:green:user2/trigger\x00', 0x2, 0x0)
write(r1, &(0x7f0000000180)='cpu', 0x3)
r2 = openat(0xffffffffffffff9c, &(0x7f0000000200)='/sys/class/leds/v2m:green:user3/trigger\x00', 0x2, 0x0)
write(r2, &(0x7f0000000280)='heartbeat', 0x9)
r3 = openat(0xffffffffffffff9c, &(0x7f0000000300)='/sys/class/leds/v2m:green:user4/trigger\x00', 0x2, 0x0)
write(r3, &(0x7f0000000380)='cpu', 0x3)
r4 = openat(0xffffffffffffff9c, &(0x7f0000000400)='/sys/class/leds/v2m:green:user5/trigger\x00', 0x2, 0x0)
write(r4, &(0x7f0000000480)='heartbeat', 0x9)
r5 = openat(0xffffffffffffff9c, &(0x7f0000000500)='/sys/class/leds/v2m:green:user6/trigger\x00', 0x2, 0x0)
write(r5, &(0x7f0000000580)='cpu', 0x3)
nanosleep(&(0x7f0000000600)={0x0, 0x2710}, 0x0)
|
| 5/2 |
2026/03/08 08:14 |
llm |
crash-repro-finder |
2m
Model:
Tokens:
input: 6156
output: 31
thoughts: 15900
Thoughts: **Reproducing the Soft Lockup in `led_heartbeat_function`**
Alright, let's break this down. The user's after a syzkaller program to trigger a soft lockup, specifically the one reported in the crash dump. That report points to a soft lockup on CPU #1, where the trace reveals a lock contention within `led_heartbeat_function`. It's a classic case of a spinlock conflict in the GPIO LED driver. My understanding is that `led_heartbeat_function` is a timer-based LED controller, and the soft lockup is happening during the `gpio_mmio_set` call. The root cause is likely a race condition where the spinlock, which protects GPIO memory access, is already held by something else when the timer softirq tries to grab it. The interrupted context appears to be the CPU exiting the idle loop, which also interacts with the same GPIO LED driver. This is likely an interrupt that occurs while the idle exit code is using the shared GPIO spinlock, causing the deadlock.
The crash report confirms that `gpio_mmio_set` uses `raw_spin_lock_irqsave` - this is the first hint. However, the `__irq_svc` call implies that interrupts were *enabled* at the time of the interrupt, which means that `raw_spin_lock_irqsave` isn't working as expected, or that they were re-enabled later. This is the crux of the problem - `raw_spin_lock_irqsave` is supposed to disable interrupts during a critical section. I checked the `gpio-mmio.c` source code, where `raw_spin_lock_irqsave` is definitely used. The stack trace does show the interruption inside the critical section of `gpio_mmio_write32`. So it is possible that interrupts are somehow re-enabled, or the lock is `raw_spin_lock` and it is not safe.
Let's summarize.
1. CPU exiting idle is setting the trigger of one LED to cpu. This involves `gpio_mmio_set`.
2. Timer interrupt is happening. The timer's softirq is also using `gpio_mmio_set` because `led_heartbeat_function` is running.
3. Both threads are using same lock. Idle exit is calling `raw_spin_lock_irqsave`. However, the other thread gets interrupted.
To reproduce this, I need two LEDs controlled by the same GPIO controller, and where the LED triggers are set to "cpu" and "heartbeat". The plan is to create a syzkaller program to set the triggers on a couple of LEDs, and use `nanosleep` or `sched_yield` to force idle/active transitions, which should increase the likelihood of hitting the race. I am assuming the `ARM-Versatile Express` hardware and the corresponding GPIO drivers are in use. Given the stack traces, the LED names on this setup are likely going to start with `v2m:green:user`, so the syzkaller program should target those. The key is to generate frequent idle entry/exit cycles on the CPU which triggers the "cpu" trigger to be active.
Here's the syzkaller program:
```syz
r0 = openat(0xffffffffffffff9c, &(0x7f0000000000)='/sys/class/leds/v2m:green:user1/trigger\x00', 0x2, 0x0)
write(r0, &(0x7f0000000080)='heartbeat', 0x9)
r1 = openat(0xffffffffffffff9c, &(0x7f0000000100)='/sys/class/leds/v2m:green:user2/trigger\x00', 0x2, 0x0)
write(r1, &(0x7f0000000180)='cpu', 0x3)
r2 = openat(0xffffffffffffff9c, &(0x7f0000000200)='/sys/class/leds/v2m:green:user3/trigger\x00', 0x2, 0x0)
write(r2, &(0x7f0000000280)='heartbeat', 0x9)
r3 = openat(0xffffffffffffff9c, &(0x7f0000000300)='/sys/
|
| 6/2 |
2026/03/08 08:17 |
tool |
set-results |
0m
Args: map[ReproOpts:{"repeat":true,"procs":1,"sandbox":"none"}]
Results: map[ReproOpts:{"repeat":true,"procs":1,"sandbox":"none"}]
|
| 7/2 |
2026/03/08 08:17 |
llm |
crash-repro-finder |
0m
Model:
Tokens:
input: 23141
output: 605
thoughts: 0
|