INFO: task syz.7.2202:19146 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.7.2202      state:D stack:24904 pid:19146 tgid:19144 ppid:13905  task_flags:0x400140 flags:0x00080002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5388 [inline]
 __schedule+0x17b4/0x5680 kernel/sched/core.c:7189
 __schedule_loop kernel/sched/core.c:7268 [inline]
 schedule+0x164/0x360 kernel/sched/core.c:7283
 schedule_timeout+0xc3/0x2c0 kernel/time/sleep_timeout.c:75
 do_wait_for_common kernel/sched/completion.c:100 [inline]
 __wait_for_common kernel/sched/completion.c:121 [inline]
 wait_for_common kernel/sched/completion.c:132 [inline]
 wait_for_completion+0x2cc/0x5e0 kernel/sched/completion.c:153
 __flush_work+0xa17/0xc50 kernel/workqueue.c:4354
 p9_mux_poll_stop net/9p/trans_fd.c:140 [inline]
 p9_conn_destroy net/9p/trans_fd.c:804 [inline]
 p9_fd_close+0x245/0x430 net/9p/trans_fd.c:840
 p9_client_create+0x68d/0xc90 net/9p/client.c:937
 v9fs_session_init+0x46/0xe60 fs/9p/v9fs.c:446
 v9fs_get_tree+0xbd/0xac0 fs/9p/vfs_super.c:97
 vfs_get_tree+0x92/0x2a0 fs/super.c:1754
 fc_mount fs/namespace.c:1193 [inline]
 do_new_mount_fc fs/namespace.c:3758 [inline]
 do_new_mount+0x341/0xd30 fs/namespace.c:3834