INFO: task syz.4.285:8845 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.4.285       state:D stack:28936 pid:8845  tgid:8824  ppid:8122   task_flags:0x400040 flags:0x00004004
Call Trace:
 <TASK>
 __schedule+0x1798/0x4cc0
 schedule+0x165/0x360
 schedule_preempt_disabled+0x13/0x30
 rwsem_down_write_slowpath+0x872/0xfe0
 down_write_nested+0x1b5/0x200
 do_rmdir+0x1b2/0x550
 __x64_sys_rmdir+0x47/0x50
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f8ff6b8eba9
RSP: 002b:00007f8ff7947038 EFLAGS: 00000246 ORIG_RAX: 0000000000000054
RAX: ffffffffffffffda RBX: 00007f8ff6dd6090 RCX: 00007f8ff6b8eba9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000200000000300
RBP: 00007f8ff6c11e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f8ff6dd6128 R14: 00007f8ff6dd6090 R15: 00007ffc206a7518
 </TASK>
INFO: task syz.4.285:8849 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.4.285       state:D stack:26376 pid:8849  tgid:8824  ppid:8122   task_flags:0x400140 flags:0x00004004
Call Trace:
 <TASK>
 __schedule+0x1798/0x4cc0
 schedule+0x165/0x360
 schedule_preempt_disabled+0x13/0x30
 rwsem_down_write_slowpath+0x872/0xfe0
 down_write_nested+0x1b5/0x200
 filename_create+0x1f8/0x3c0
 do_mkdirat+0xa0/0x590
 __x64_sys_mkdir+0x6c/0x80
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f8ff6b8eba9
RSP: 002b:00007f8ff49d3038 EFLAGS: 00000246 ORIG_RAX: 0000000000000053
RAX: ffffffffffffffda RBX: 00007f8ff6dd6270 RCX: 00007f8ff6b8eba9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00002000000000c0
RBP: 00007f8ff6c11e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f8ff6dd6308 R14: 00007f8ff6dd6270 R15: 00007ffc206a7518
 </TASK>

Showing all locks held in the system:
3 locks held by kworker/u8:1/13:
 #0: ffff88801c3c3148 ((wq_completion)cfg80211){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0
 #1: ffffc90000107bc0 ((work_completion)(&(&rdev->dfs_update_channels_wk)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0
 #2: ffffffff8f539f48 (rtnl_mutex){+.+.}-{4:4}, at: cfg80211_dfs_channels_update_work+0xb6/0x630
3 locks held by kworker/u9:0/26:
 #0: ffff88801a489148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0
 #1: ffffc900001efbc0 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0
 #2: ffffffff8f539f48 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60
1 lock held by khungtaskd/34:
 #0: ffffffff8e13a0e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180
4 locks held by kworker/u10:2/40:
 #0: ffff88801b387948 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0
 #1: ffffc900006efbc0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0
 #2: ffff8880271c40e0 (&type->s_umount_key#74){++++}-{4:4}, at: super_trylock_shared+0x20/0xf0
 #3: ffff88802907e730 (&jfs_ip->commit_mutex){+.+.}-{4:4}, at: jfs_commit_inode+0x1ca/0x530
1 lock held by dhcpcd/5594:
 #0: ffffffff8f539f48 (rtnl_mutex){+.+.}-{4:4}, at: devinet_ioctl+0x323/0x1b50
2 locks held by getty/5679:
 #0: ffff88810e3460a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70
 #1: ffffc900029062f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400
4 locks held by kworker/u8:4/5905:
 #0: ffff88801b2f7148 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0
 #1: ffffc9000346fbc0 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0
 #2: ffffffff8f52d090 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf7/0x800
 #3: ffffffff8f539f48 (rtnl_mutex){+.+.}-{4:4}, at: wiphy_unregister+0x244/0xae0
2 locks held by syz-executor/8142:
4 locks held by syz.4.285/8825:
2 locks held by syz.4.285/8845:
 #0: ffff8880271c4428 (sb_writers#21){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90
 #1: ffff88802907eae0 (&type->i_mutex_dir_key#15/1){+.+.}-{4:4}, at: do_rmdir+0x1b2/0x550
2 locks held by syz.4.285/8849:
 #0: ffff8880271c4428 (sb_writers#21){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90
 #1: ffff88802907eae0 (&type->i_mutex_dir_key#15/1){+.+.}-{4:4}, at: filename_create+0x1f8/0x3c0
1 lock held by syz.5.363/9601:
 #0: ffff8880371020e0 (&type->s_umount_key#56){++++}-{4:4}, at: super_lock+0x2a9/0x3b0
1 lock held by syz.8.462/10556:
 #0: ffff8880371020e0 (&type->s_umount_key#56){++++}-{4:4}, at: super_lock+0x2a9/0x3b0
3 locks held by syz-executor/10995:
 #0: ffffffff8eca94a0 (&ops->srcu#2){.+.+}-{0:0}, at: rtnl_link_ops_get+0x23/0x250
 #1: ffffffff8f539f48 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8db/0x1c70
 #2: ffffffff8e13fb78 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2f6/0x730
1 lock held by syz.1.506/11036:
 #0: ffffffff8e13fb78 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x3b9/0x730
1 lock held by syz-executor/11044:
 #0: ffffffff8f539f48 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x3b0/0x18b0

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

NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 34 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
Call Trace:
 <TASK>
 dump_stack_lvl+0x189/0x250
 nmi_cpu_backtrace+0x39e/0x3d0
 nmi_trigger_cpumask_backtrace+0x17a/0x300
 watchdog+0xf93/0xfe0
 kthread+0x711/0x8a0
 ret_from_fork+0x439/0x7d0
 ret_from_fork_asm+0x1a/0x30
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 151 Comm: kworker/u9:2 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
Workqueue: events_unbound nsim_dev_trap_report_work
RIP: 0010:chacha_block_generic+0x432/0xc80
Code: 30 4c 89 f8 48 c1 e8 03 0f b6 04 10 84 c0 0f 85 8f 06 00 00 41 03 2f 4c 8d 63 30 4c 8d 6b 33 4c 89 e0 48 c1 e8 03 0f b6 04 10 <84> c0 0f 85 95 06 00 00 4c 89 e8 48 c1 e8 03 0f b6 04 10 84 c0 0f
RSP: 0018:ffffc9000257f5c0 EFLAGS: 00000802
RAX: 0000000000000000 RBX: ffffc9000257f680 RCX: 00000000eb17967f
RDX: dffffc0000000000 RSI: ffffc9000257f5e4 RDI: ffffc9000257f5ec
RBP: 00000000c6bb3453 R08: 00000000ded9dee0 R09: ffffc9000257f5e8
R10: 00000000103c933e R11: 000000005d0def22 R12: ffffc9000257f6b0
R13: ffffc9000257f6b3 R14: ffffc9000257f860 R15: ffffc9000257f890
FS:  0000000000000000(0000) GS:ffff8881a3c15000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffd3eec1038 CR3: 000000000df36000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 crng_fast_key_erasure+0x14f/0x240
 crng_make_state+0x255/0x700
 _get_random_bytes+0xd5/0x210
 nsim_dev_trap_report_work+0x69e/0xb80
 process_scheduled_works+0xae1/0x17b0
 worker_thread+0x8a0/0xda0
 kthread+0x711/0x8a0
 ret_from_fork+0x439/0x7d0
 ret_from_fork_asm+0x1a/0x30
 </TASK>
