syzbot

INFO: task syz-executor.3:27881 blocked for more than 143 seconds.
      Not tainted 5.16.0-rc1-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor.3  state:D stack:25392 pid:27881 ppid: 10207 flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:4972 [inline]
 __schedule+0xb72/0x1460 kernel/sched/core.c:6253
 schedule+0x12b/0x1f0 kernel/sched/core.c:6326
 blk_mq_freeze_queue_wait+0x105/0x190 block/blk-mq.c:178
 __loop_clr_fd+0x1c6/0x9b0 drivers/block/loop.c:1122
 loop_clr_fd drivers/block/loop.c:1237 [inline]
 lo_ioctl+0x107b/0x1f40 drivers/block/loop.c:1562
 blkdev_ioctl+0x3ac/0x790 block/ioctl.c:609
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:874 [inline]
 __se_sys_ioctl+0xfb/0x170 fs/ioctl.c:860
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x44/0xd0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7f04480e18a7
RSP: 002b:00007f0445635fa8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000020000180 RCX: 00007f04480e18a7
RDX: 0000000000000000 RSI: 0000000000004c01 RDI: 0000000000000008
RBP: 00007f04456366bc R08: 00007f0445636040 R09: 0000000020000000
R10: 0000000000000001 R11: 0000000000000246 R12: ffffffffffffffff
R13: 0000000000000005 R14: 00007f0445636000 R15: 0000000020000380
 </TASK>
INFO: task syz-executor.3:27908 blocked for more than 143 seconds.
      Not tainted 5.16.0-rc1-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor.3  state:D stack:27088 pid:27908 ppid: 10207 flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:4972 [inline]
 __schedule+0xb72/0x1460 kernel/sched/core.c:6253
 schedule+0x12b/0x1f0 kernel/sched/core.c:6326
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6385
 __mutex_lock_common+0xd1f/0x2590 kernel/locking/mutex.c:680
 __mutex_lock kernel/locking/mutex.c:740 [inline]
 mutex_lock_nested+0x1a/0x20 kernel/locking/mutex.c:792
 blkdev_get_by_dev+0xfc/0xb80 block/bdev.c:819
 blkdev_open+0x137/0x2f0 block/fops.c:501
 do_dentry_open+0x78b/0x1020 fs/open.c:822
 do_open fs/namei.c:3426 [inline]
 path_openat+0x2896/0x3660 fs/namei.c:3559
 do_filp_open+0x277/0x4f0 fs/namei.c:3586
 do_sys_openat2+0x13b/0x500 fs/open.c:1212
 do_sys_open fs/open.c:1228 [inline]
 __do_sys_openat fs/open.c:1244 [inline]
 __se_sys_openat fs/open.c:1239 [inline]
 __x64_sys_openat+0x243/0x290 fs/open.c:1239
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x44/0xd0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7f0448094a04
RSP: 002b:00007f0445614ed0 EFLAGS: 00000293 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007f044812b970 RCX: 00007f0448094a04
RDX: 0000000000000002 RSI: 00007f0445615000 RDI: 00000000ffffff9c
RBP: 00007f0445615000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000002
R13: 0000000000000007 R14: 0000000020000180 R15: 0000000000000000
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/27:
 #0: ffffffff8cb1dc00 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30
1 lock held by in:imklog/6215:
 #0: ffff8880718760f0 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x24e/0x2f0 fs/file.c:990
2 locks held by kworker/u4:10/10788:
2 locks held by systemd-udevd/27524:
 #0: ffff88801b38d918 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev+0xfc/0xb80 block/bdev.c:819
 #1: ffff88801b389360 (&lo->lo_mutex){+.+.}-{3:3}, at: lo_open+0x68/0x100 drivers/block/loop.c:1733
1 lock held by syz-executor.3/27881:
 #0: ffff88801b389360 (&lo->lo_mutex){+.+.}-{3:3}, at: __loop_clr_fd+0x6d/0x9b0 drivers/block/loop.c:1106
1 lock held by syz-executor.3/27908:
 #0: ffff88801b38d918 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev+0xfc/0xb80 block/bdev.c:819

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

NMI backtrace for cpu 0
CPU: 0 PID: 27 Comm: khungtaskd Not tainted 5.16.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1dc/0x2d8 lib/dump_stack.c:106
 nmi_cpu_backtrace+0x45f/0x490 lib/nmi_backtrace.c:111
 nmi_trigger_cpumask_backtrace+0x16a/0x280 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:210 [inline]
 watchdog+0xc82/0xcd0 kernel/hung_task.c:295
 kthread+0x468/0x490 kernel/kthread.c:327
 ret_from_fork+0x1f/0x30
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 2954 Comm: systemd-journal Not tainted 5.16.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:__lock_acquire+0x1d66/0x2b00 kernel/locking/lockdep.c:5054
Code: 0d 45 31 ff 48 be 00 00 00 00 00 fc ff df 48 c7 84 24 c0 00 00 00 0e 36 e0 45 48 8b 84 24 b8 00 00 00 48 c7 04 06 00 00 00 00 <65> 48 8b 04 25 28 00 00 00 48 3b 84 24 00 01 00 00 0f 85 df 0c 00
RSP: 0018:ffffc90001b0f780 EFLAGS: 00000083
RAX: 1ffff92000361f08 RBX: ffff88807b4dc450 RCX: ffff88807b4dc458
RDX: 0000000000000000 RSI: dffffc0000000000 RDI: ffffffff8ff99ee8
RBP: ffffc90001b0f8d0 R08: dffffc0000000000 R09: fffffbfff1ff33de
R10: fffffbfff1ff33de R11: 0000000000000000 R12: ffff88807b4dba00
R13: ffff88807b4dc488 R14: ffffffff8f8e5c40 R15: 0000000000000001
FS:  00007f1b0d84d8c0(0000) GS:ffff8880b9b00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f1b0ad8a020 CR3: 000000001ce10000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 lock_acquire+0x19f/0x4d0 kernel/locking/lockdep.c:5637
 __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline]
 _raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:154
 spin_lock include/linux/spinlock.h:349 [inline]
 fast_dput fs/dcache.c:764 [inline]
 dput+0x313/0x6e0 fs/dcache.c:875
 path_put fs/namei.c:557 [inline]
 terminate_walk+0x3dc/0x570 fs/namei.c:676
 path_parentat fs/namei.c:2504 [inline]
 filename_parentat+0x2be/0x7b0 fs/namei.c:2519
 filename_create+0xf4/0x4e0 fs/namei.c:3637
 do_mkdirat+0xae/0x530 fs/namei.c:3898
 __do_sys_mkdir fs/namei.c:3929 [inline]
 __se_sys_mkdir fs/namei.c:3927 [inline]
 __x64_sys_mkdir+0x6a/0x80 fs/namei.c:3927
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x44/0xd0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7f1b0cb08687
Code: 00 b8 ff ff ff ff c3 0f 1f 40 00 48 8b 05 09 d8 2b 00 64 c7 00 5f 00 00 00 b8 ff ff ff ff c3 0f 1f 40 00 b8 53 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d e1 d7 2b 00 f7 d8 64 89 01 48
RSP: 002b:00007ffece61c808 EFLAGS: 00000293 ORIG_RAX: 0000000000000053
RAX: ffffffffffffffda RBX: 00007ffece61f720 RCX: 00007f1b0cb08687
RDX: 00007f1b0d579a00 RSI: 00000000000001ed RDI: 000056299aad48a0
RBP: 00007ffece61c840 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000069 R11: 0000000000000293 R12: 0000000000000000
R13: 0000000000000000 R14: 00007ffece61f720 R15: 00007ffece61cd30
 </TASK>
----------------
Code disassembly (best guess), 1 bytes skipped:
   0:	45 31 ff             	xor    %r15d,%r15d
   3:	48 be 00 00 00 00 00 	movabs $0xdffffc0000000000,%rsi
   a:	fc ff df
   d:	48 c7 84 24 c0 00 00 	movq   $0x45e0360e,0xc0(%rsp)
  14:	00 0e 36 e0 45
  19:	48 8b 84 24 b8 00 00 	mov    0xb8(%rsp),%rax
  20:	00
  21:	48 c7 04 06 00 00 00 	movq   $0x0,(%rsi,%rax,1)
  28:	00
* 29:	65 48 8b 04 25 28 00 	mov    %gs:0x28,%rax <-- trapping instruction
  30:	00 00
  32:	48 3b 84 24 00 01 00 	cmp    0x100(%rsp),%rax
  39:	00
  3a:	0f                   	.byte 0xf
  3b:	85 df                	test   %ebx,%edi
  3d:	0c 00                	or     $0x0,%al