INFO: task syz.2.550:7760 blocked for more than 143 seconds.
Tainted: G L syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.2.550 state:D stack:25640 pid:7760 tgid:7758 ppid:5817 task_flags:0x400140 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5295 [inline]
__schedule+0x1585/0x5310 kernel/sched/core.c:6907
__schedule_loop kernel/sched/core.c:6989 [inline]
schedule+0x164/0x360 kernel/sched/core.c:7004
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7061
__mutex_lock_common kernel/locking/mutex.c:692 [inline]
__mutex_lock+0x7fe/0x1300 kernel/locking/mutex.c:776
sync_bdevs+0x27e/0x470 block/bdev.c:1304
ksys_sync fs/sync.c:105 [inline]
__ia32_sys_sync+0xc5/0x120 fs/sync.c:111
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f45c519aeb9
RSP: 002b:00007f45c603f028 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2
RAX: ffffffffffffffda RBX: 00007f45c5415fa0 RCX: 00007f45c519aeb9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007f45c5415fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f45c5416038 R14: 00007f45c5415fa0 R15: 00007ffe3ff49e68
Showing all locks held in the system:
5 locks held by kworker/1:0/24:
#0: ffff888021ab6d48 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x855/0x1650 kernel/workqueue.c:3254
#1: ffffc900001e7c40 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x87c/0x1650 kernel/workqueue.c:3255
#2: ffff88802a8f6198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline]
#2: ffff88802a8f6198 (&dev->mutex){....}-{4:4}, at: hub_event+0x17f/0x4f30 drivers/usb/core/hub.c:5899
#3: ffff888054d44198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline]
#3: ffff888054d44198 (&dev->mutex){....}-{4:4}, at: __device_attach+0x88/0x450 drivers/base/dd.c:1008
#4: ffff888058859160 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline]
#4: ffff888058859160 (&dev->mutex){....}-{4:4}, at: __device_attach+0x88/0x450 drivers/base/dd.c:1008
1 lock held by khungtaskd/31:
#0: ffffffff8e960320 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline]
#0: ffffffff8e960320 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline]
#0: ffffffff8e960320 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
3 locks held by kworker/u8:5/1000:
#0: ffff88813fe04148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x855/0x1650 kernel/workqueue.c:3254
#1: ffffc90003c1fc40 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work+0x87c/0x1650 kernel/workqueue.c:3255
#2: ffffffff8fde84c8 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:313
1 lock held by klogd/5177:
1 lock held by dhcpcd/5483:
#0: ffffffff8fde84c8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
#0: ffffffff8fde84c8 (rtnl_mutex){+.+.}-{4:4}, at: inet6_rtm_newaddr+0x65f/0xe30 net/ipv6/addrconf.c:5032
2 locks held by getty/5575:
#0: ffff8880333180a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc9000332b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45c/0x13c0 drivers/tty/n_tty.c:2211
1 lock held by udevd/5939:
#0: ffff888027051358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xd30 block/bdev.c:961
3 locks held by kworker/u8:9/7140:
#0:
ffff888032832948 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x855/0x1650 kernel/workqueue.c:3254
#1: ffffc900033a7c40 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work+0x87c/0x1650 kernel/workqueue.c:3255
#2: ffffffff8fde84c8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
#2: ffffffff8fde84c8 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_dad_work+0x11e/0x14c0 net/ipv6/addrconf.c:4199
1 lock held by syz.2.550/7760:
#0: ffff888027051358 (&disk->open_mutex){+.+.}-{4:4}, at: sync_bdevs+0x27e/0x470 block/bdev.c:1304
1 lock held by syz.9.1188/9994:
#0: ffffffff8e966480 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x580 kernel/rcu/tree.c:3828
2 locks held by syz.8.1189/9995:
#0: ffffffff8fde84c8 (rtnl_mutex){+.+.}-{4:4}, at: tun_detach drivers/net/tun.c:634 [inline]
#0: ffffffff8fde84c8 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x3e/0x1c0 drivers/net/tun.c:3436
#1: ffffffff8e9665b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:343 [inline]
#1: ffffffff8e9665b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x38d/0x770 kernel/rcu/tree_exp.h:961
=============================================
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/24/2026
Call Trace:
dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:161 [inline]
__sys_info lib/sys_info.c:157 [inline]
sys_info+0x135/0x170 lib/sys_info.c:165
check_hung_uninterruptible_tasks kernel/hung_task.c:347 [inline]
watchdog+0x103d/0x1090 kernel/hung_task.c:516
kthread+0x388/0x470 kernel/kthread.c:467
ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 1000 Comm: kworker/u8:5 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/24/2026
Workqueue: bat_events batadv_tt_purge
RIP: 0010:hlock_class kernel/locking/lockdep.c:234 [inline]
RIP: 0010:mark_lock+0x3c/0x190 kernel/locking/lockdep.c:4731
Code: 00 03 00 83 f9 01 bb 09 00 00 00 83 db 00 83 fa 08 0f 45 da bd 01 00 00 00 89 d9 d3 e5 25 ff 1f 00 00 48 0f a3 05 84 59 a6 12 <73> 10 48 69 c0 c8 00 00 00 48 8d 88 10 84 e9 93 eb 42 83 3d 4b e9
RSP: 0018:ffffc90003c1f9a8 EFLAGS: 00000003
RAX: 0000000000000861 RBX: 0000000000000002 RCX: 0000000000000002
RDX: 0000000000000002 RSI: ffff8880275f2980 RDI: ffff8880275f1e40
RBP: 0000000000000004 R08: ffffffff903342b7 R09: 1ffffffff2066856
R10: dffffc0000000000 R11: fffffbfff2066857 R12: ffff8880275f2980
R13: dffffc0000000000 R14: ffff8880275f2958 R15: 0000000000000001
FS: 0000000000000000(0000) GS:ffff888125015000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055d5340e14a6 CR3: 0000000075c28000 CR4: 00000000003526f0
Call Trace:
mark_held_locks kernel/locking/lockdep.c:4325 [inline]
__trace_hardirqs_on_caller kernel/locking/lockdep.c:4343 [inline]
lockdep_hardirqs_on_prepare+0x110/0x260 kernel/locking/lockdep.c:4410
trace_hardirqs_on+0x28/0x40 kernel/trace/trace_preemptirq.c:78
__local_bh_enable_ip+0xd0/0x130 kernel/softirq.c:455
spin_unlock_bh include/linux/spinlock.h:395 [inline]
batadv_tt_local_purge+0x2a7/0x340 net/batman-adv/translation-table.c:1315
batadv_tt_purge+0x35/0x9e0 net/batman-adv/translation-table.c:3509
process_one_work+0x949/0x1650 kernel/workqueue.c:3279
process_scheduled_works kernel/workqueue.c:3362 [inline]
worker_thread+0xb46/0x1140 kernel/workqueue.c:3443
kthread+0x388/0x470 kernel/kthread.c:467
ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
----------------
Code disassembly (best guess):
0: 00 03 add %al,(%rbx)
2: 00 83 f9 01 bb 09 add %al,0x9bb01f9(%rbx)
8: 00 00 add %al,(%rax)
a: 00 83 db 00 83 fa add %al,-0x57cff25(%rbx)
10: 08 0f or %cl,(%rdi)
12: 45 da bd 01 00 00 00 rex.RB fidivrl 0x1(%r13)
19: 89 d9 mov %ebx,%ecx
1b: d3 e5 shl %cl,%ebp
1d: 25 ff 1f 00 00 and $0x1fff,%eax
22: 48 0f a3 05 84 59 a6 bt %rax,0x12a65984(%rip) # 0x12a659ae
29: 12
* 2a: 73 10 jae 0x3c <-- trapping instruction
2c: 48 69 c0 c8 00 00 00 imul $0xc8,%rax,%rax
33: 48 8d 88 10 84 e9 93 lea -0x6c167bf0(%rax),%rcx
3a: eb 42 jmp 0x7e
3c: 83 .byte 0x83
3d: 3d .byte 0x3d
3e: 4b rex.WXB
3f: e9 .byte 0xe9