INFO: task syz.3.878:9535 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.3.878       state:D stack:27496 pid:9535  tgid:9534  ppid:9352   task_flags:0x400140 flags:0x00080002
Call Trace:
 <TASK>
 __schedule+0x17d9/0x56c0
 schedule+0x164/0x2b0
 schedule_timeout+0xc0/0x2c0
 __down_common+0x3b7/0x850
 down+0x80/0xd0
 console_lock+0x58/0x90
 rotate_store+0x2c/0x500
 kernfs_fop_write_iter+0x3a4/0x540
 vfs_write+0x612/0xba0
 ksys_write+0x150/0x270
 do_syscall_64+0x174/0x580
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f1f5719e0d9
RSP: 002b:00007f1f58048028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f1f57425fa0 RCX: 00007f1f5719e0d9
RDX: 000000000000002d RSI: 0000200000000240 RDI: 0000000000000004
RBP: 00007f1f57235024 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f1f57426038 R14: 00007f1f57425fa0 R15: 00007ffdf585a578
 </TASK>
INFO: task syz.0.923:9695 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.0.923       state:D stack:27288 pid:9695  tgid:9694  ppid:9259   task_flags:0x400040 flags:0x00080002
Call Trace:
 <TASK>
 __schedule+0x17d9/0x56c0
 schedule+0x164/0x2b0
 schedule_preempt_disabled+0x13/0x30
 __mutex_lock+0x7bf/0x1550
 tty_open+0x204/0xcc0
 chrdev_open+0x4d9/0x600
 do_dentry_open+0x816/0x1380
 vfs_open+0x3b/0x340
 path_openat+0x2e44/0x3830
 do_file_open+0x23e/0x4a0
 do_sys_openat2+0x115/0x200
 __x64_sys_openat+0x138/0x170
 do_syscall_64+0x174/0x580
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f42d555e90e
RSP: 002b:00007f42d63feb28 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007f42d63ff6c0 RCX: 00007f42d555e90e
RDX: 0000000000000002 RSI: 00007f42d63fec00 RDI: ffffffffffffff9c
RBP: 00007f42d5635024 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f42d5826038 R14: 00007f42d5825fa0 R15: 00007ffeb5f32b38
 </TASK>

Showing all locks held in the system:
3 locks held by kworker/0:0/9:
 #0: ffff88810006b140 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0
 #1: ffffc900000e7c40 ((work_completion)(&helper->damage_work)){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0
 #2: ffff888109807270 (&helper->lock){+.+.}-{4:4}, at: drm_fb_helper_damage_work+0x15b/0xf20
1 lock held by rcu_preempt/16:
 #0: ffff88812103b1e0 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2d/0x160
1 lock held by khungtaskd/35:
 #0: ffffffff8eb59c60 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180
2 locks held by getty/5422:
 #0: ffff88817383f0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70
 #1: ffffc900034762e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45a/0x1360
3 locks held by kworker/0:5/5781:
1 lock held by syz.5.648/8311:
 #0: ffffffff8f4581c0 (tty_mutex){+.+.}-{4:4}, at: tty_release_struct+0xae/0xd0
1 lock held by syz.7.744/8694:
 #0: ffffffff8f4581c0 (tty_mutex){+.+.}-{4:4}, at: tty_release_struct+0xae/0xd0
10 locks held by syz.9.824/9038:
2 locks held by syz.8.830/9062:
 #0: ffffffff8f4581c0 (tty_mutex){+.+.}-{4:4}, at: tty_open+0x204/0xcc0
 #1: ffff88811d58b1b0 (&tty->legacy_mutex){+.+.}-{4:4}, at: tty_init_dev+0x74/0x4d0
7 locks held by kworker/0:8/9528:
4 locks held by syz.3.878/9535:
 #0: ffff88818cd9f6f0 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x246/0x320
 #1: ffff8881bcda6450 (sb_writers#7){.+.+}-{0:0}, at: vfs_write+0x22b/0xba0
 #2: ffff888172cafc80 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1d8/0x540
 #3: ffff888103ae51e8 (kn->active#58){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x22b/0x540
1 lock held by syz.0.923/9695:
 #0: ffffffff8f4581c0 (tty_mutex){+.+.}-{4:4}, at: tty_open+0x204/0xcc0
1 lock held by syz.5.993/10038:
 #0: ffffffff8f4581c0 (tty_mutex){+.+.}-{4:4}, at: tty_open+0x204/0xcc0
1 lock held by syz.8.1122/10760:
 #0: ffffffff8f4581c0 (tty_mutex){+.+.}-{4:4}, at: ptmx_open+0xdc/0x2e0
1 lock held by syz.0.1208/11250:
 #0: ffffffff8f4581c0 (tty_mutex){+.+.}-{4:4}, at: tty_open+0x204/0xcc0
1 lock held by syz.3.1220/11286:
 #0: ffffffff8f4581c0 (tty_mutex){+.+.}-{4:4}, at: tty_open+0x204/0xcc0
1 lock held by syz.4.1282/11554:
 #0: ffffffff8f4581c0 (tty_mutex){+.+.}-{4:4}, at: ptmx_open+0xdc/0x2e0
1 lock held by syz.4.1282/11559:
 #0: ffffffff8f4581c0 (tty_mutex){+.+.}-{4:4}, at: tty_open+0x204/0xcc0
1 lock held by syz.5.1291/11605:
 #0: ffffffff8f4581c0 (tty_mutex){+.+.}-{4:4}, at: ptmx_open+0xdc/0x2e0
1 lock held by syz.7.1388/12125:
 #0: ffffffff8f4581c0 (tty_mutex){+.+.}-{4:4}, at: tty_open+0x204/0xcc0
1 lock held by syz.7.1388/12126:
 #0: ffffffff8f4581c0 (tty_mutex){+.+.}-{4:4}, at: tty_open+0x204/0xcc0
1 lock held by syz.9.1420/12324:
 #0: ffffffff8f4581c0 (tty_mutex){+.+.}-{4:4}, at: tty_open+0x204/0xcc0
1 lock held by syz.8.1440/12447:
 #0: ffffffff8f4581c0 (tty_mutex){+.+.}-{4:4}, at: tty_open+0x204/0xcc0

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

NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 35 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: 9038 Comm: syz.9.824 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:memcpy_toio+0x7c/0xe0
Code: 02 40 0f 94 c5 31 ff e8 62 48 b4 fc b0 01 48 83 fb 02 73 4f 84 c0 74 51 e8 71 43 b4 fc 48 89 d9 48 c1 e9 02 4c 89 fe 4c 89 f7 <f3> a5 f6 c3 02 74 02 66 a5 f6 c3 01 74 01 a4 5b 41 5e 41 5f 5d e9
RSP: 0018:ffffc900076b7288 EFLAGS: 00010206
RAX: ffffffff8512a7ef RBX: 0000000000001400 RCX: 0000000000000242
RDX: ffffc90030012000 RSI: ffffc90004917af8 RDI: ffffc900050e6af8
RBP: 0000000000001401 R08: ffffc900076b7470 R09: 0000000000000001
R10: ffffc900076b7499 R11: fffff52000ed6e94 R12: ffff888109a2ca58
R13: ffffc900050e6000 R14: ffffc900050e6000 R15: ffffc90004917000
FS:  00007f895fa906c0(0000) GS:ffff88818d956000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b30e23ffc CR3: 000000010b5fe000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 drm_fb_memcpy+0x325/0x5d0
 bochs_primary_plane_helper_atomic_update+0x361/0xa30
 drm_atomic_helper_commit_planes+0x626/0xea0
 drm_atomic_helper_commit_tail+0x60/0x510
 commit_tail+0x2b1/0x3c0
 drm_atomic_helper_commit+0xa77/0xb10
 drm_atomic_commit+0x24e/0x2b0
 drm_client_modeset_commit_atomic+0x660/0x7e0
 drm_client_modeset_commit_locked+0xcb/0x4d0
 drm_fb_helper_pan_display+0x3e9/0xbe0
 fb_pan_display+0x3a3/0x6a0
 bit_update_start+0x4c/0x1e0
 fbcon_modechanged+0xb30/0x1140
 rotate_store+0x32d/0x500
 kernfs_fop_write_iter+0x3a4/0x540
 vfs_write+0x612/0xba0
 ksys_write+0x150/0x270
 do_syscall_64+0x174/0x580
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f895eb9e0d9
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 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 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f895fa90028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f895ee25fa0 RCX: 00007f895eb9e0d9
RDX: 000000000000002d RSI: 0000200000000240 RDI: 0000000000000004
RBP: 00007f895ec35024 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f895ee26038 R14: 00007f895ee25fa0 R15: 00007ffdb1a65958
 </TASK>
