INFO: task kworker/u8:5:13389 blocked for more than 430 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u8:5    state:D stack:0     pid:13389 tgid:13389 ppid:2      task_flags:0x4208060 flags:0x00000000
Workqueue: ib-unreg-wq ib_unregister_work
Call Trace:
[<ffffffff8653d390>] context_switch kernel/sched/core.c:5325 [inline]
[<ffffffff8653d390>] __schedule+0x1042/0x4114 kernel/sched/core.c:6929
[<ffffffff86540526>] __schedule_loop kernel/sched/core.c:7011 [inline]
[<ffffffff86540526>] schedule+0xc4/0x35e kernel/sched/core.c:7026
[<ffffffff86555fbe>] schedule_timeout+0x1c6/0x2ae kernel/time/sleep_timeout.c:75
[<ffffffff865420d6>] do_wait_for_common kernel/sched/completion.c:100 [inline]
[<ffffffff865420d6>] __wait_for_common+0x1d2/0x3e8 kernel/sched/completion.c:121
[<ffffffff86542306>] wait_for_common kernel/sched/completion.c:132 [inline]
[<ffffffff86542306>] wait_for_completion+0x1a/0x22 kernel/sched/completion.c:153
[<ffffffff847274ae>] disable_device+0x1b2/0x2ba drivers/infiniband/core/device.c:1325
[<ffffffff84727844>] __ib_unregister_device+0x28e/0x402 drivers/infiniband/core/device.c:1555
[<ffffffff847279d8>] ib_unregister_work+0x20/0x36 drivers/infiniband/core/device.c:1667
[<ffffffff801c6f18>] process_one_work+0x96a/0x1f3a kernel/workqueue.c:3263
[<ffffffff801ca030>] process_scheduled_works kernel/workqueue.c:3346 [inline]
[<ffffffff801ca030>] worker_thread+0x5ce/0xde8 kernel/workqueue.c:3427
[<ffffffff801e7768>] kthread+0x39c/0x7d6 kernel/kthread.c:463
[<ffffffff800699de>] ret_from_fork_kernel+0x2a/0xbc6 arch/riscv/kernel/process.c:214
[<ffffffff8655c446>] ret_from_fork_kernel_asm+0x16/0x18 arch/riscv/kernel/entry.S:328

Showing all locks held in the system:
1 lock held by khungtaskd/33:
 #0: ffffffff885df1a0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2a/0x1a0 kernel/locking/lockdep.c:6771
2 locks held by getty/3164:
 #0: ffffaf80137e30a0 (&tty->ldisc_sem){++++}-{0:0}, at: ldsem_down_read+0x3a/0x46 drivers/tty/tty_ldsem.c:340
 #1: ffff8f800008e2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x3e4/0x12b6 drivers/tty/n_tty.c:2222
2 locks held by syz-executor/3189:
3 locks held by kworker/u8:6/5582:
3 locks held by kworker/u8:5/13389:
 #0: ffffaf8012bb9148 ((wq_completion)ib-unreg-wq){+.+.}-{0:0}, at: process_one_work+0x848/0x1f3a kernel/workqueue.c:3238
 #1: ffff8f80047a7b70 ((work_completion)(&device->unregistration_work)){+.+.}-{0:0}, at: process_one_work+0x870/0x1f3a kernel/workqueue.c:3238
 #2: ffffaf8030924700 (&device->unregistration_lock){+.+.}-{4:4}, at: __ib_unregister_device+0x200/0x402 drivers/infiniband/core/device.c:1551
3 locks held by kworker/u8:7/13845:
 #0: ffffaf80126a3148 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x848/0x1f3a kernel/workqueue.c:3238
 #1: ffff8f8002287b70 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x870/0x1f3a kernel/workqueue.c:3238
 #2: ffffffff89aa6330 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xcc/0x7f0 net/core/net_namespace.c:669
2 locks held by kworker/1:1/13994:
1 lock held by syz-executor/14264:
3 locks held by kworker/0:2/14704:
3 locks held by syz.0.2986/14846:

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

NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 33 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT 
Hardware name: riscv-virtio,qemu (DT)
Call Trace:
[<ffffffff8007941a>] dump_backtrace+0x2e/0x3c arch/riscv/kernel/stacktrace.c:132
[<ffffffff8000329a>] show_stack+0x30/0x3c arch/riscv/kernel/stacktrace.c:138
[<ffffffff80060c50>] __dump_stack lib/dump_stack.c:94 [inline]
[<ffffffff80060c50>] dump_stack_lvl+0x12a/0x1a2 lib/dump_stack.c:120
[<ffffffff80060ce4>] dump_stack+0x1c/0x24 lib/dump_stack.c:129
[<ffffffff864f4502>] nmi_cpu_backtrace+0x3b0/0x3b2 lib/nmi_backtrace.c:113
[<ffffffff864f47ba>] nmi_trigger_cpumask_backtrace+0x2b6/0x45a lib/nmi_backtrace.c:62
[<ffffffff80087228>] arch_trigger_cpumask_backtrace+0x2c/0x3c arch/riscv/kernel/smp.c:350
[<ffffffff80506152>] trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline]
[<ffffffff80506152>] check_hung_uninterruptible_tasks kernel/hung_task.c:332 [inline]
[<ffffffff80506152>] watchdog+0xf58/0x11ac kernel/hung_task.c:495
[<ffffffff801e7768>] kthread+0x39c/0x7d6 kernel/kthread.c:463
[<ffffffff800699de>] ret_from_fork_kernel+0x2a/0xbc6 arch/riscv/kernel/process.c:214
[<ffffffff8655c446>] ret_from_fork_kernel_asm+0x16/0x18 arch/riscv/kernel/entry.S:328
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 3013 Comm: klogd Not tainted syzkaller #0 PREEMPT 
Hardware name: riscv-virtio,qemu (DT)
epc : format_decode+0x110/0xdfe lib/vsprintf.c:2671
 ra : format_decode+0x110/0xdfe lib/vsprintf.c:2671
epc : ffffffff8650e418 ra : ffffffff8650e418 sp : ffff8f8003c77520
 gp : ffffffff89edc9e0 tp : ffffaf801d46b500 t0 : 00007fff99c362f8
 t1 : ffff8f8003c777a0 t2 : 2030203a44495520 s0 : ffff8f8003c77650
 s1 : 0000000000000000 a0 : 0000000000000001 a1 : 0000000000000003
 a2 : 0000000000000002 a3 : ffffffff8650e418 a4 : 0000000000000000
 a5 : ffffaf801d46c500 a6 : 0000000000000003 a7 : ffff8f8003c77947
 s2 : ffff8f8003c775a0 s3 : ffff8f8003c776c0 s4 : ffffffff86a53020
 s5 : ffff8f8003c775e0 s6 : 0000000000000054 s7 : ffff8f8003c778c0
 s8 : ffff8f8003c77858 s9 : ffff8f8003c778cc s10: ffffffff879b84fc
 s11: 000000007fffffff t3 : 1ffff1f00078eef4 t4 : fffff1ef0078ef28
 t5 : fffff1ef0078ef29 t6 : ffff8f8003c779e1
status: 0000000200000120 badaddr: 0000000000000000 cause: 8000000000000001
[<ffffffff8650e418>] format_decode+0x110/0xdfe lib/vsprintf.c:2671
[<ffffffff8651ce94>] vsnprintf+0x162/0xaba lib/vsprintf.c:2869
[<ffffffff8651dd66>] snprintf+0x9c/0xc8 lib/vsprintf.c:3020
[<ffffffff80304228>] print_caller kernel/printk/printk.c:1363 [inline]
[<ffffffff80304228>] info_print_prefix+0x136/0x31a kernel/printk/printk.c:1382
[<ffffffff80304562>] record_print_text+0x156/0x3d8 kernel/printk/printk.c:1429
[<ffffffff80304c82>] syslog_print+0x49e/0x652 kernel/printk/printk.c:1640
[<ffffffff80309300>] do_syslog+0x408/0xa58 kernel/printk/printk.c:1758
[<ffffffff803099c0>] __do_sys_syslog kernel/printk/printk.c:1850 [inline]
[<ffffffff803099c0>] __se_sys_syslog kernel/printk/printk.c:1848 [inline]
[<ffffffff803099c0>] __riscv_sys_syslog+0x70/0xa2 kernel/printk/printk.c:1848
[<ffffffff800770dc>] syscall_handler+0x94/0x118 arch/riscv/include/asm/syscall.h:112
[<ffffffff86532a22>] do_trap_ecall_u+0x39e/0x53a arch/riscv/kernel/traps.c:343
[<ffffffff8655c326>] handle_exception+0x146/0x152 arch/riscv/kernel/entry.S:198