syzbot

INFO: task syz-executor.3:16565 blocked for more than 143 seconds.
      Not tainted 5.10.0-rc2-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor.3  state:D stack:25720 pid:16565 ppid:  8484 flags:0x00004004
Call Trace:
 context_switch kernel/sched/core.c:3774 [inline]
 __schedule+0x92c/0xcb0 kernel/sched/core.c:4523
 schedule+0x14b/0x200 kernel/sched/core.c:4601
 schedule_timeout+0x15c/0x250 kernel/time/timer.c:1871
 gfs2_gl_hash_clear+0x128/0x380 fs/gfs2/glock.c:1989
 gfs2_fill_super+0x2aa7/0x3db0 fs/gfs2/ops_fstype.c:1233
 get_tree_bdev+0x3e9/0x5f0 fs/super.c:1344
 gfs2_get_tree+0x4c/0x1f0 fs/gfs2/ops_fstype.c:1256
 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
Code: Unable to access opcode bytes at RIP 0x4608e0.
RSP: 002b:00007f033bf9ca88 EFLAGS: 00000202 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007f033bf9cb20 RCX: 000000000046090a
RDX: 0000000020000000 RSI: 0000000020000100 RDI: 00007f033bf9cae0
RBP: 00007f033bf9cae0 R08: 00007f033bf9cb20 R09: 0000000020000000
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000020000000
R13: 0000000020000100 R14: 0000000020000200 R15: 0000000020047a20

Showing all locks held in the system:
8 locks held by kworker/u4:4/1028:
1 lock held by khungtaskd/1643:
 #0: ffffffff8bae6800 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30 arch/x86/pci/mmconfig_64.c:151
1 lock held by in:imklog/8167:
 #0: ffff888019343c70 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x24b/0x2e0 fs/file.c:932
1 lock held by syz-executor.3/16565:
 #0: ffff8880243680e0 (&type->s_umount_key#65/1){+.+.}-{3:3}, at: alloc_super+0x1a7/0x860 fs/super.c:229

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

NMI backtrace for cpu 0
CPU: 0 PID: 1643 Comm: khungtaskd Not tainted 5.10.0-rc2-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+0xcb0/0xcf0 kernel/hung_task.c:294
 kthread+0x36b/0x390 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: 4881 Comm: systemd-journal Not tainted 5.10.0-rc2-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:rcu_lockdep_current_cpu_online+0xd8/0x100 kernel/rcu/tree.c:1156
Code: c6 70 4c 89 f0 48 c1 e8 03 42 80 3c 38 00 74 08 4c 89 f7 e8 ca 6b 55 00 49 23 1e 0f 95 c0 65 ff 0d e9 63 a0 7e 74 06 5b 41 5e <41> 5f c3 e8 9f c0 9e ff eb f3 48 c7 c7 20 ae ae 8b 48 89 de e8 7f
RSP: 0018:ffffc9000133fd18 EFLAGS: 00000282
RAX: 1ffffffff175d401 RBX: 0000000000000000 RCX: 0000000080000001
RDX: 0000000000000000 RSI: 0000000000000002 RDI: ffff8880b9d35658
RBP: 0000000000000002 R08: dffffc0000000000 R09: fffffbfff19dc46e
R10: fffffbfff19dc46e R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: dffffc0000000000
FS:  00007fab182728c0(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fab15795020 CR3: 00000000119fc000 CR4: 00000000001506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 rcu_read_lock_held_common kernel/rcu/update.c:110 [inline]
 rcu_read_lock_sched_held+0x2c/0xb0 kernel/rcu/update.c:121
 trace_lock_acquire+0x6b/0x180 include/trace/events/lock.h:13
 lock_acquire+0x39/0x5e0 kernel/locking/lockdep.c:5407
 rcu_lock_acquire+0x2a/0x30 include/linux/rcupdate.h:248
 rcu_read_lock include/linux/rcupdate.h:641 [inline]
 mntput_no_expire+0x7e/0xce0 fs/namespace.c:1143
 do_faccessat+0x580/0x870 fs/open.c:457
 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x7fab1752e9c7
Code: 83 c4 08 48 3d 01 f0 ff ff 73 01 c3 48 8b 0d c8 d4 2b 00 f7 d8 64 89 01 48 83 c8 ff c3 66 0f 1f 44 00 00 b8 15 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d a1 d4 2b 00 f7 d8 64 89 01 48
RSP: 002b:00007ffdbf3bb118 EFLAGS: 00000246 ORIG_RAX: 0000000000000015
RAX: ffffffffffffffda RBX: 00007ffdbf3be030 RCX: 00007fab1752e9c7
RDX: 00007fab17f9fa00 RSI: 0000000000000000 RDI: 000055625c8ea9a3
RBP: 00007ffdbf3bb150 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000069 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007ffdbf3be030 R15: 00007ffdbf3bb640