INFO: task syz-executor.0:11006 blocked for more than 143 seconds.
      Not tainted 5.12.0-rc2-next-20210310-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor.0  state:D stack:26576 pid:11006 ppid:  8430 flags:0x00004004
Call Trace:
 context_switch kernel/sched/core.c:4353 [inline]
 __schedule+0x90c/0x2150 kernel/sched/core.c:5103
 schedule+0xcf/0x270 kernel/sched/core.c:5182
 io_uring_cancel_files fs/io_uring.c:8678 [inline]
 io_uring_cancel_task_requests+0xc0d/0x1180 fs/io_uring.c:8704
 __io_uring_files_cancel+0x10a/0x1b0 fs/io_uring.c:8812
 io_uring_files_cancel include/linux/io_uring.h:47 [inline]
 do_exit+0x299/0x2a60 kernel/exit.c:780
 do_group_exit+0x125/0x310 kernel/exit.c:922
 get_signal+0x42c/0x2100 kernel/signal.c:2773
 arch_do_signal_or_restart+0x2a8/0x1eb0 arch/x86/kernel/signal.c:811
 handle_signal_work kernel/entry/common.c:147 [inline]
 exit_to_user_mode_loop kernel/entry/common.c:171 [inline]
 exit_to_user_mode_prepare+0x148/0x250 kernel/entry/common.c:208
 __syscall_exit_to_user_mode_work kernel/entry/common.c:290 [inline]
 syscall_exit_to_user_mode+0x19/0x50 kernel/entry/common.c:301
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x465f69
RSP: 002b:00007fefd67b4188 EFLAGS: 00000246 ORIG_RAX: 00000000000001aa
RAX: 0000000000000302 RBX: 000000000056bf60 RCX: 0000000000465f69
RDX: 0000000000000000 RSI: 0000000000000302 RDI: 0000000000000004
RBP: 00000000004bfa3f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056bf60
R13: 00007fff084247af R14: 00007fefd67b4300 R15: 0000000000022000

Showing all locks held in the system:
1 lock held by khungtaskd/1667:
 #0: ffffffff8bf74360 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:6332
1 lock held by in:imklog/8131:
 #0: ffff8880117ae0f0 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe9/0x100 fs/file.c:961
5 locks held by kworker/0:11/10627:

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

NMI backtrace for cpu 1
CPU: 1 PID: 1667 Comm: khungtaskd Not tainted 5.12.0-rc2-next-20210310-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:79 [inline]
 dump_stack+0x141/0x1d7 lib/dump_stack.c:120
 nmi_cpu_backtrace.cold+0x44/0xd7 lib/nmi_backtrace.c:105
 nmi_trigger_cpumask_backtrace+0x1b3/0x230 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:147 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:253 [inline]
 watchdog+0xd8e/0xf40 kernel/hung_task.c:338
 kthread+0x3b1/0x4a0 kernel/kthread.c:292
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 180 Comm: kworker/u4:4 Not tainted 5.12.0-rc2-next-20210310-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: bat_events batadv_nc_worker
RIP: 0010:__lock_release kernel/locking/lockdep.c:5217 [inline]
RIP: 0010:lock_release+0x2bd/0x720 kernel/locking/lockdep.c:5531
Code: 83 6b 22 10 66 f7 43 22 f0 ff 0f 85 0c 01 00 00 4c 89 f2 44 8b 64 24 50 48 b8 00 00 00 00 00 fc ff df 48 c1 ea 03 0f b6 04 02 <84> c0 74 08 3c 03 0f 8e 87 03 00 00 48 89 da 45 89 a7 90 09 00 00
RSP: 0018:ffffc90000f9fb48 EFLAGS: 00000802
RAX: 0000000000000000 RBX: ffff8880120589e8 RCX: ffffc90000f9fb98
RDX: 1ffff1100240b132 RSI: 0000000000000000 RDI: ffff888012058a0a
RBP: 1ffff920001f3f6b R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000002
R13: 0000000000000003 R14: ffff888012058990 R15: ffff888012058000
FS:  0000000000000000(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f7b0278d000 CR3: 000000001dc6f000 CR4: 00000000001506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 __raw_spin_unlock_bh include/linux/spinlock_api_smp.h:174 [inline]
 _raw_spin_unlock_bh+0x12/0x30 kernel/locking/spinlock.c:207
 spin_unlock_bh include/linux/spinlock.h:399 [inline]
 batadv_nc_purge_paths+0x2a5/0x3a0 net/batman-adv/network-coding.c:467
 batadv_nc_worker+0x831/0xe50 net/batman-adv/network-coding.c:716
 process_one_work+0x98d/0x1600 kernel/workqueue.c:2275
 worker_thread+0x64c/0x1120 kernel/workqueue.c:2421
 kthread+0x3b1/0x4a0 kernel/kthread.c:292
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294