INFO: task syz.4.869:11059 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.4.869       state:D stack:26016 pid:11059 tgid:11058 ppid:6297   task_flags:0x400140 flags:0x00080002
Call Trace:
 <TASK>
 __schedule+0x15dd/0x52d0
 schedule+0x164/0x360
 schedule_preempt_disabled+0x13/0x30
 rwsem_down_read_slowpath+0x61e/0x920
 down_read+0x99/0x2e0
 super_lock+0x2d6/0x3d0
 __iterate_supers+0x126/0x290
 drop_caches_sysctl_handler+0x97/0x170
 proc_sys_call_handler+0x4c8/0x830
 do_iter_readv_writev+0x619/0x8c0
 vfs_writev+0x33c/0x990
 do_writev+0x154/0x2e0
 do_syscall_64+0x14d/0xf80
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f7e2c79c799
RSP: 002b:00007f7e2d5f0028 EFLAGS: 00000246 ORIG_RAX: 0000000000000014
RAX: ffffffffffffffda RBX: 00007f7e2ca15fa0 RCX: 00007f7e2c79c799
RDX: 0000000000000001 RSI: 0000200000000080 RDI: 0000000000000004
RBP: 00007f7e2c832c99 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f7e2ca16038 R14: 00007f7e2ca15fa0 R15: 00007ffc2bf8bbc8
 </TASK>
INFO: task syz.4.869:11061 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.4.869       state:D stack:26464 pid:11061 tgid:11058 ppid:6297   task_flags:0x400140 flags:0x00080002
Call Trace:
 <TASK>
 __schedule+0x15dd/0x52d0
 schedule+0x164/0x360
 schedule_preempt_disabled+0x13/0x30
 __mutex_lock+0x7fe/0x1300
 fdget_pos+0x246/0x320
 do_writev+0x80/0x2e0
 do_syscall_64+0x14d/0xf80
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f7e2c79c799
RSP: 002b:00007f7e2d5cf028 EFLAGS: 00000246 ORIG_RAX: 0000000000000014
RAX: ffffffffffffffda RBX: 00007f7e2ca16090 RCX: 00007f7e2c79c799
RDX: 0000000000000001 RSI: 0000200000000080 RDI: 0000000000000004
RBP: 00007f7e2c832c99 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f7e2ca16128 R14: 00007f7e2ca16090 R15: 00007ffc2bf8bbc8
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/35:
 #0: ffffffff8e75e520 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180
2 locks held by getty/5634:
 #0: ffff88816e9c70a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70
 #1: ffffc9000356b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45c/0x13c0
2 locks held by syz-executor/9688:
3 locks held by syz.4.869/11059:
 #0: ffff88817702d0f8 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x246/0x320
 #1: ffff888120796420 (sb_writers#3){.+.+}-{0:0}, at: vfs_writev+0x2aa/0x990
 #2: ffff8881b5dda0e0 (&type->s_umount_key#61){++++}-{4:4}, at: super_lock+0x2d6/0x3d0
1 lock held by syz.4.869/11061:
 #0: ffff88817702d0f8 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x246/0x320
2 locks held by syz-executor/12748:
1 lock held by syz.2.1071/12876:
 #0: ffff8881b5dda0e0 (&type->s_umount_key#61){++++}-{4:4}, at: super_lock+0x2d6/0x3d0
1 lock held by syz-executor/14204:
 #0: ffffffff8e7647b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2d0/0x770
3 locks held by syz.9.1384/15357:

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

NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 35 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+0xe8/0x150
 nmi_cpu_backtrace+0x274/0x2d0
 nmi_trigger_cpumask_backtrace+0x17a/0x300
 sys_info+0x135/0x170
 watchdog+0xfd9/0x1030
 kthread+0x388/0x470
 ret_from_fork+0x51e/0xb90
 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: 15357 Comm: syz.9.1384 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
RIP: 0010:vprintk_emit+0x45d/0x560
Code: 0f 84 44 ff ff ff e8 d2 2d 21 00 fb eb 44 e8 ca 2d 21 00 e8 75 df 09 0a 4d 85 f6 74 94 e8 bb 2d 21 00 fb 48 c7 c7 60 09 75 8e <31> f6 ba 01 00 00 00 31 c9 41 b8 01 00 00 00 45 31 c9 53 e8 cb 16
RSP: 0018:ffffc9000695f5e0 EFLAGS: 00000283
RAX: ffffffff81a47325 RBX: ffffffff81a4719f RCX: 0000000000080000
RDX: ffffc9002ab63000 RSI: 000000000000eb00 RDI: ffffffff8e750960
RBP: ffffc9000695f690 R08: ffffffff90119ab7 R09: 1ffffffff2023356
R10: dffffc0000000000 R11: fffffbfff2023357 R12: 0000000000000000
R13: 0000000000000047 R14: 0000000000000200 R15: 1ffff92000d2bec0
FS:  00007fedb1d9b6c0(0000) GS:ffff8882a9460000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fedb0f86340 CR3: 0000000175732000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 _printk+0xdd/0x130
 f2fs_printk+0x48a/0x520
 sanity_check_area_boundary+0x67b/0xe20
 f2fs_fill_super+0x18f5/0x7740
 get_tree_bdev_flags+0x431/0x4f0
 vfs_get_tree+0x92/0x2a0
 do_new_mount+0x341/0xd30
 __se_sys_mount+0x31d/0x420
 do_syscall_64+0x14d/0xf80
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fedb0f9da0a
Code: 48 c7 c2 e8 ff ff ff f7 d8 64 89 02 b8 ff ff ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 49 89 ca b8 a5 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fedb1d9ae58 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007fedb1d9aee0 RCX: 00007fedb0f9da0a
RDX: 0000200000000140 RSI: 0000200000000000 RDI: 00007fedb1d9aea0
RBP: 0000200000000140 R08: 00007fedb1d9aee0 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000200000000000
R13: 00007fedb1d9aea0 R14: 000000000000551c R15: 0000200000000380
 </TASK>
