syzbot

INFO: task systemd-udevd:23749 blocked for more than 143 seconds.
      Not tainted 5.10.0-rc5-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:systemd-udevd   state:D stack:27760 pid:23749 ppid:  4892 flags:0x00004100
Call Trace:
 context_switch kernel/sched/core.c:3779 [inline]
 __schedule+0x92c/0xcb0 kernel/sched/core.c:4528
 schedule+0x14b/0x200 kernel/sched/core.c:4606
 io_schedule+0x83/0x100 kernel/sched/core.c:6301
 bit_wait_io+0xb/0x90 kernel/sched/wait_bit.c:209
 __wait_on_bit_lock+0xc3/0x1a0 kernel/sched/wait_bit.c:90
 out_of_line_wait_on_bit_lock+0x169/0x1d0 kernel/sched/wait_bit.c:117
 wait_on_bit_lock_io include/linux/wait_bit.h:208 [inline]
 __lock_buffer fs/buffer.c:69 [inline]
 lock_buffer include/linux/buffer_head.h:366 [inline]
 block_read_full_page+0x8fe/0xd20 fs/buffer.c:2325
 generic_file_buffered_read+0x1372/0x3b40 mm/filemap.c:2397
 call_read_iter include/linux/fs.h:1897 [inline]
 new_sync_read fs/read_write.c:415 [inline]
 vfs_read+0x869/0xa80 fs/read_write.c:496
 ksys_read+0x11b/0x220 fs/read_write.c:634
 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x7f46058a0210
RSP: 002b:00007fff4ff42ca8 EFLAGS: 00000246 ORIG_RAX: 0000000000000000
RAX: ffffffffffffffda RBX: 0000563ca3023450 RCX: 00007f46058a0210
RDX: 0000000000000400 RSI: 0000563ca3023478 RDI: 000000000000000f
RBP: 0000563ca3022950 R08: 00007f460588af98 R09: 0000000000000430
R10: 0000563ca3023468 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000400 R14: 0000563ca30229a0 R15: 0000000000000400
INFO: task syz-executor.1:23819 blocked for more than 143 seconds.
      Not tainted 5.10.0-rc5-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor.1  state:D stack:28216 pid:23819 ppid:  8463 flags:0x00004004
Call Trace:
 context_switch kernel/sched/core.c:3779 [inline]
 __schedule+0x92c/0xcb0 kernel/sched/core.c:4528
 schedule+0x14b/0x200 kernel/sched/core.c:4606
 io_schedule+0x83/0x100 kernel/sched/core.c:6301
 bit_wait_io+0xb/0x90 kernel/sched/wait_bit.c:209
 __wait_on_bit+0xbd/0x190 kernel/sched/wait_bit.c:49
 out_of_line_wait_on_bit+0x169/0x1d0 kernel/sched/wait_bit.c:64
 wait_on_bit_io include/linux/wait_bit.h:101 [inline]
 __wait_on_buffer fs/buffer.c:122 [inline]
 wait_on_buffer include/linux/buffer_head.h:354 [inline]
 __bread_slow fs/buffer.c:1210 [inline]
 __bread_gfp+0x28a/0x350 fs/buffer.c:1402
 sb_bread include/linux/buffer_head.h:301 [inline]
 nilfs_read_super_block+0x82/0xe0 fs/nilfs2/super.c:842
 nilfs_load_super_block+0xd4/0xd20 fs/nilfs2/the_nilfs.c:495
 init_nilfs+0x67/0x10e0 fs/nilfs2/the_nilfs.c:577
 nilfs_fill_super fs/nilfs2/super.c:1046 [inline]
 nilfs_mount+0x682/0xfa0 fs/nilfs2/super.c:1316
 legacy_get_tree+0xea/0x180 fs/fs_context.c:592
 vfs_get_tree+0x88/0x270 fs/super.c:1549
 do_new_mount fs/namespace.c:2875 [inline]
 path_mount+0x17b4/0x2a20 fs/namespace.c:3205
 do_mount fs/namespace.c:3218 [inline]
 __do_sys_mount fs/namespace.c:3426 [inline]
 __se_sys_mount+0x28c/0x320 fs/namespace.c:3403
 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x46090a
RSP: 002b:00007f52d0b93a88 EFLAGS: 00000202 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007f52d0b93b20 RCX: 000000000046090a
RDX: 0000000020000000 RSI: 0000000020000100 RDI: 00007f52d0b93ae0
RBP: 00007f52d0b93ae0 R08: 00007f52d0b93b20 R09: 0000000020000000
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000020000000
R13: 0000000020000100 R14: 0000000020000200 R15: 0000000020015900

Showing all locks held in the system:
1 lock held by khungtaskd/1645:
 #0: ffffffff8bce6940 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30 arch/x86/pci/mmconfig_64.c:151
6 locks held by kworker/1:1H/2979:
1 lock held by in:imklog/8128:
 #0: ffff888012c814f0 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x24b/0x2e0 fs/file.c:932
2 locks held by syz-executor.1/23819:
 #0: ffff888067b520e0 (&type->s_umount_key#58/1){+.+.}-{3:3}, at: alloc_super+0x1a7/0x860 fs/super.c:229
 #1: ffff88802ea90090 (&nilfs->ns_sem){++++}-{3:3}, at: init_nilfs+0x36/0x10e0 fs/nilfs2/the_nilfs.c:569

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

NMI backtrace for cpu 0
CPU: 0 PID: 1645 Comm: khungtaskd Not tainted 5.10.0-rc5-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x137/0x1be lib/dump_stack.c:118
 nmi_cpu_backtrace+0x16c/0x190 lib/nmi_backtrace.c:105
 nmi_trigger_cpumask_backtrace+0x191/0x2f0 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:209 [inline]
 watchdog+0xcde/0xd20 kernel/hung_task.c:294
 kthread+0x39a/0x3c0 kernel/kthread.c:292
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:296
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 2979 Comm: kworker/1:1H Not tainted 5.10.0-rc5-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: events_highpri snd_vmidi_output_work
RIP: 0010:check_wait_context kernel/locking/lockdep.c:4507 [inline]
RIP: 0010:__lock_acquire+0x5f8/0x5e90 kernel/locking/lockdep.c:4782
Code: 48 8d 04 5b 48 c1 e0 06 48 8d 98 80 8a c7 8e 48 ba 00 00 00 00 00 fc ff df 48 81 c3 ba 00 00 00 48 89 d8 48 c1 e8 03 8a 04 10 <84> c0 0f 85 bb 24 00 00 0f b7 1b 48 8b 44 24 48 8a 04 10 84 c0 0f
RSP: 0018:ffffc9000177f6f0 EFLAGS: 00000802
RAX: 1ffffffff1d9e000 RBX: ffffffff8ecf05fa RCX: ffffffff8158fc53
RDX: dffffc0000000000 RSI: 0000000000000008 RDI: ffffffff8ee9f438
RBP: ffffc9000177f8a0 R08: dffffc0000000000 R09: fffffbfff1dd3e88
R10: fffffbfff1dd3e88 R11: 0000000000000000 R12: ffff888019fb3480
R13: ffff888019fb3e30 R14: 0000000000000002 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fff4ff45ac7 CR3: 00000000151f5000 CR4: 00000000001526e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 lock_acquire+0x114/0x5e0 kernel/locking/lockdep.c:5437
 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
 _raw_spin_lock_irqsave+0x73/0xa0 kernel/locking/spinlock.c:159
 snd_seq_oss_readq_put_event sound/core/seq/oss/seq_oss_readq.c:145 [inline]
 snd_seq_oss_readq_puts+0xb5/0x340 sound/core/seq/oss/seq_oss_readq.c:100
 send_midi_event sound/core/seq/oss/seq_oss_midi.c:609 [inline]
 snd_seq_oss_midi_input+0x41a/0xd10 sound/core/seq/oss/seq_oss_midi.c:524
 snd_seq_deliver_single_event+0x4d4/0xbd0 sound/core/seq/seq_clientmgr.c:638
 deliver_to_subscribers sound/core/seq/seq_clientmgr.c:693 [inline]
 snd_seq_deliver_event+0x4aa/0x900 sound/core/seq/seq_clientmgr.c:828
 snd_seq_kernel_client_dispatch+0x1f6/0x2f0 sound/core/seq/seq_clientmgr.c:2323
 snd_vmidi_output_work+0x21b/0x3b0 sound/core/seq/seq_virmidi.c:150
 process_one_work+0x789/0xfc0 kernel/workqueue.c:2272
 worker_thread+0xaa4/0x1460 kernel/workqueue.c:2418
 kthread+0x39a/0x3c0 kernel/kthread.c:292
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:296