INFO: task syz-executor761:27320 blocked for more than 140 seconds.
      Not tainted 4.19.211-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor761 D28416 27320   8123 0x00000004
Call Trace:
 context_switch kernel/sched/core.c:2828 [inline]
 __schedule+0x887/0x2040 kernel/sched/core.c:3517
 schedule+0x8d/0x1b0 kernel/sched/core.c:3561
 schedule_timeout+0x92d/0xfe0 kernel/time/timer.c:1794
 do_wait_for_common kernel/sched/completion.c:83 [inline]
 __wait_for_common kernel/sched/completion.c:104 [inline]
 wait_for_common+0x29c/0x470 kernel/sched/completion.c:115
 __flush_work+0x4bb/0x8b0 kernel/workqueue.c:2926
 __cancel_work_timer+0x412/0x590 kernel/workqueue.c:3013
 p9_conn_destroy net/9p/trans_fd.c:899 [inline]
 p9_fd_close+0x29c/0x520 net/9p/trans_fd.c:934
 p9_client_create+0x901/0x12e0 net/9p/client.c:1084
 v9fs_session_init+0x1dd/0x1770 fs/9p/v9fs.c:421
 v9fs_mount+0x73/0x910 fs/9p/vfs_super.c:135
 mount_fs+0xa3/0x310 fs/super.c:1261
 vfs_kern_mount.part.0+0x68/0x470 fs/namespace.c:961
 vfs_kern_mount fs/namespace.c:951 [inline]
 do_new_mount fs/namespace.c:2492 [inline]
 do_mount+0x115c/0x2f50 fs/namespace.c:2822
 ksys_mount+0xcf/0x130 fs/namespace.c:3038
 __do_sys_mount fs/namespace.c:3052 [inline]
 __se_sys_mount fs/namespace.c:3049 [inline]
 __x64_sys_mount+0xba/0x150 fs/namespace.c:3049
 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x7f8544dbf6f9
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 41 15 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f8544d702f8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007f8544e484c0 RCX: 00007f8544dbf6f9
RDX: 0000000020000040 RSI: 0000000020000000 RDI: 0000000000000000
RBP: 00007f8544e1507c R08: 0000000020000180 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0030656c69662f2e
R13: 64663d736e617274 R14: 006c6f6f74687465 R15: 00007f8544e484c8

Showing all locks held in the system:
1 lock held by khungtaskd/1570:
 #0: 00000000018adc24 (rcu_read_lock){....}, at: debug_show_all_locks+0x53/0x265 kernel/locking/lockdep.c:4441
1 lock held by in:imklog/7787:
 #0: 00000000a4778eaf (&f->f_pos_lock){+.+.}, at: __fdget_pos+0x26f/0x310 fs/file.c:767
2 locks held by kworker/0:0/11679:
 #0: 00000000b5f335c4 ((wq_completion)"events"){+.+.}, at: process_one_work+0x767/0x1570 kernel/workqueue.c:2124
 #1: 000000009aa4ca69 ((work_completion)(&m->rq)){+.+.}, at: process_one_work+0x79c/0x1570 kernel/workqueue.c:2128

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

NMI backtrace for cpu 0
CPU: 0 PID: 1570 Comm: khungtaskd Not tainted 4.19.211-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x1fc/0x2ef lib/dump_stack.c:118
 nmi_cpu_backtrace.cold+0x63/0xa2 lib/nmi_backtrace.c:101
 nmi_trigger_cpumask_backtrace+0x1a6/0x1f0 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:203 [inline]
 watchdog+0x991/0xe60 kernel/hung_task.c:287
 kthread+0x33f/0x460 kernel/kthread.c:259
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1 skipped: idling at native_safe_halt+0xe/0x10 arch/x86/include/asm/irqflags.h:60