INFO: task syz.7.4052:19395 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.7.4052      state:D stack:28512 pid:19395 tgid:19394 ppid:18168  task_flags:0x400140 flags:0x00080002
Call Trace:
 <TASK>
 __schedule+0x17d9/0x56c0
 schedule+0x164/0x2b0
 cgroup_lock_and_drain_offline+0x51a/0x650
 cgroup1_get_tree+0x9d/0x890
 vfs_get_tree+0x92/0x2a0
 do_new_mount+0x319/0xdc0
 __se_sys_mount+0x31d/0x420
 do_syscall_64+0x174/0x580
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f110cf9e019
RSP: 002b:00007f110ddf1028 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007f110d225fa0 RCX: 00007f110cf9e019
RDX: 00002000000001c0 RSI: 0000200000000100 RDI: 0000000000000000
RBP: 00007f110d03500c R08: 0000200000000000 R09: 0000000000000000
R10: 0000000002010042 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f110d226038 R14: 00007f110d225fa0 R15: 00007ffd1d73db68
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/34:
 #0: ffffffff8eb59ca0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180
1 lock held by klogd/5049:
 #0: ffff88812103b160 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2d/0x160
2 locks held by getty/5439:
 #0: ffff888169e670a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70
 #1: ffffc900034732e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45a/0x1360
2 locks held by syz.5.889/8840:
2 locks held by syz.5.1099/9497:
2 locks held by syz.5.2134/13078:
2 locks held by syz.5.2627/14693:
2 locks held by syz.5.3983/19167:
2 locks held by syz.5.4012/19272:
2 locks held by syz.5.4068/19441:
1 lock held by syz.1.4920/22442:
 #0: ffffffff8eb5ffa8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2d0/0x770

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

NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 34 Comm: khungtaskd Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
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+0xe8/0x150
 nmi_cpu_backtrace+0x274/0x2d0
 nmi_trigger_cpumask_backtrace+0x17a/0x380
 sys_info+0x135/0x170
 watchdog+0xfd7/0x1030
 kthread+0x388/0x470
 ret_from_fork+0x514/0xb70
 ret_from_fork_asm+0x1a/0x30
 </TASK>
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 19167 Comm: syz.5.3983 Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
RIP: 0010:mas_start+0x99/0x640
Code: df e8 9b d4 6b f6 4c 8b 33 4d 8d 66 40 4c 89 e0 48 c1 e8 03 42 0f b6 04 28 84 c0 0f 85 ef 04 00 00 bd 00 03 00 00 41 23 2c 24 <bf> 00 03 00 00 89 ee e8 2b 16 fe f5 81 fd 00 03 00 00 75 4d e8 de
RSP: 0018:ffffc900074c76e8 EFLAGS: 00000206
RAX: 0000000000000000 RBX: ffffc900074c7920 RCX: 0000000000000000
RDX: ffff888173b73c00 RSI: 0000000000000001 RDI: 0000000000000001
RBP: 0000000000000300 R08: ffff888173b73c00 R09: 0000000000000006
R10: 0000000000000007 R11: 0000000000000000 R12: ffff888113af7340
R13: dffffc0000000000 R14: ffff888113af7300 R15: dffffc0000000000
FS:  00007fbe563546c0(0000) GS:ffff88818d94d000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fc8b6287e20 CR3: 000000000e946000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 mas_walk+0x1db/0x490
 mas_find+0x635/0xcb0
 tear_down_vmas+0x339/0x520
 exit_mmap+0x4ca/0x9f0
 __mmput+0x118/0x420
 exit_mm+0x221/0x2d0
 do_exit+0x6cd/0x2360
 do_group_exit+0x22d/0x2f0
 get_signal+0x121b/0x12c0
 arch_do_signal_or_restart+0xbb/0x860
 exit_to_user_mode_loop+0x104/0x730
 do_syscall_64+0x353/0x580
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fbe5535e84e
Code: Unable to access opcode bytes at 0x7fbe5535e824.
RSP: 002b:00007fbe56353f58 EFLAGS: 00000246 ORIG_RAX: 00000000000000e6
RAX: fffffffffffffdfc RBX: 00007fbe563546c0 RCX: 00007fbe5535e84e
RDX: 00007fbe56353fb0 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007fbe5543500c R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fbe55626038 R14: 00007fbe55625fa0 R15: 00007ffe001f1218
 </TASK>
