INFO: task syz-executor7:4966 blocked for more than 140 seconds.
      Not tainted 4.9.123-g8dd3fc2 #27
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor7   D27880  4966  14050 0x00000004
 ffff8801977d6000 0000000000000000 ffff8801d0273480 ffff8801d9a6b000
 ffff8801db321c18 ffff880199e1f720 ffffffff839f0dbd dffffc0000000000
 ffff8801bac0e110 ffff880199e1f6e0 00ff8801977d68c0 ffff8801db3224e8
Call Trace:
 [<ffffffff839f23bf>] schedule+0x7f/0x1b0 kernel/sched/core.c:3553
 [<ffffffff815cc3f2>] d_wait_lookup fs/dcache.c:2454 [inline]
 [<ffffffff815cc3f2>] d_alloc_parallel+0xeb2/0x17c0 fs/dcache.c:2536
 [<ffffffff8159953c>] lookup_slow+0x19c/0x470 fs/namei.c:1650
 [<ffffffff815a5b66>] walk_component+0x716/0x1bb0 fs/namei.c:1784
 [<ffffffff815a84c6>] lookup_last fs/namei.c:2266 [inline]
 [<ffffffff815a84c6>] path_lookupat.isra.41+0x186/0x410 fs/namei.c:2283
 [<ffffffff815adf77>] filename_lookup.part.55+0x177/0x370 fs/namei.c:2317
 [<ffffffff815ae333>] filename_lookup fs/namei.c:2310 [inline]
 [<ffffffff815ae333>] user_path_at_empty+0x53/0x70 fs/namei.c:2578
 [<ffffffff815f4a50>] user_path_at include/linux/namei.h:55 [inline]
 [<ffffffff815f4a50>] path_listxattr+0xa0/0x140 fs/xattr.c:643
 [<ffffffff815f63ca>] SYSC_listxattr fs/xattr.c:658 [inline]
 [<ffffffff815f63ca>] SyS_listxattr+0x2a/0x40 fs/xattr.c:655
 [<ffffffff81006316>] do_syscall_64+0x1a6/0x490 arch/x86/entry/common.c:282
 [<ffffffff83a01c93>] entry_SYSCALL_64_after_swapgs+0x5d/0xdb

Showing all locks held in the system:
2 locks held by khungtaskd/519:
 #0:  (rcu_read_lock){......}, at: [<ffffffff81368a9c>] check_hung_uninterruptible_tasks kernel/hung_task.c:168 [inline]
 #0:  (rcu_read_lock){......}, at: [<ffffffff81368a9c>] watchdog+0x11c/0xa20 kernel/hung_task.c:239
 #1:  (tasklist_lock){.+.+..}, at: [<ffffffff81428308>] debug_show_all_locks+0x79/0x218 kernel/locking/lockdep.c:4336
1 lock held by rsyslogd/3653:
 #0:  (&f->f_pos_lock){+.+.+.}, at: [<ffffffff815dc88c>] __fdget_pos+0xac/0xd0 fs/file.c:781
2 locks held by getty/3750:
 #0:  (&tty->ldisc_sem){++++++}, at: [<ffffffff839ffe62>] ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:367
 #1:  (&ldata->atomic_read_lock){+.+.+.}, at: [<ffffffff821253c2>] n_tty_read+0x202/0x16e0 drivers/tty/n_tty.c:2142
1 lock held by syz-executor7/4961:
 #0:  (&sb->s_type->i_mutex_key#19){++++++}, at: [<ffffffff815994e1>] inode_lock_shared include/linux/fs.h:776 [inline]
 #0:  (&sb->s_type->i_mutex_key#19){++++++}, at: [<ffffffff815994e1>] lookup_slow+0x141/0x470 fs/namei.c:1645
1 lock held by syz-executor7/4966:
 #0:  (&sb->s_type->i_mutex_key#19){++++++}, at: [<ffffffff815994e1>] inode_lock_shared include/linux/fs.h:776 [inline]
 #0:  (&sb->s_type->i_mutex_key#19){++++++}, at: [<ffffffff815994e1>] lookup_slow+0x141/0x470 fs/namei.c:1645
1 lock held by syz-executor7/4969:
 #0:  (&sb->s_type->i_mutex_key#19){++++++}, at: [<ffffffff815994e1>] inode_lock_shared include/linux/fs.h:776 [inline]
 #0:  (&sb->s_type->i_mutex_key#19){++++++}, at: [<ffffffff815994e1>] lookup_slow+0x141/0x470 fs/namei.c:1645

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

NMI backtrace for cpu 0
CPU: 0 PID: 519 Comm: khungtaskd Not tainted 4.9.123-g8dd3fc2 #27
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
 ffff8801d8647d08 ffffffff81eb9689 0000000000000000 0000000000000000
 0000000000000000 0000000000000001 ffffffff810b9fa0 ffff8801d8647d40
 ffffffff81ec49c7 0000000000000000 0000000000000000 0000000000000003
Call Trace:
 [<ffffffff81eb9689>] __dump_stack lib/dump_stack.c:15 [inline]
 [<ffffffff81eb9689>] dump_stack+0xc1/0x128 lib/dump_stack.c:51
 [<ffffffff81ec49c7>] nmi_cpu_backtrace.cold.2+0x48/0x87 lib/nmi_backtrace.c:99
 [<ffffffff81ec495a>] nmi_trigger_cpumask_backtrace+0x12a/0x14f lib/nmi_backtrace.c:60
 [<ffffffff810ba0a4>] arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:37
 [<ffffffff81369034>] trigger_all_cpu_backtrace include/linux/nmi.h:58 [inline]
 [<ffffffff81369034>] check_hung_task kernel/hung_task.c:125 [inline]
 [<ffffffff81369034>] check_hung_uninterruptible_tasks kernel/hung_task.c:182 [inline]
 [<ffffffff81369034>] watchdog+0x6b4/0xa20 kernel/hung_task.c:239
 [<ffffffff8119f3cd>] kthread+0x26d/0x300 kernel/kthread.c:211
 [<ffffffff83a01e5c>] ret_from_fork+0x5c/0x70 arch/x86/entry/entry_64.S:373
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 0 Comm: swapper/1 Not tainted 4.9.123-g8dd3fc2 #27
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
task: ffff8801d9a6b000 task.stack: ffff8801d9a80000
RIP: 0010:[<ffffffff8114d39f>] 
c [<ffffffff8114d39f>] is_idle_task include/linux/sched.h:2796 [inline]
RIP: 0010:[<ffffffff8114d39f>] 
c [<ffffffff8114d39f>] irq_enter+0x2f/0xd0 kernel/softirq.c:343
RSP: 0018:ffff8801db307fc8  EFLAGS: 00000802
RAX: 0000000000000000 RBX: ffff8801d9a6b000 RCX: 1ffffffff0886881
RDX: 1ffff1003b34d6a4 RSI: ffffffff81f2110b RDI: ffff8801d9a6b520
RBP: ffff8801db307fd0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000001 R14: ffffffff84c5f210 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff8801db300000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f8e10d9b000 CR3: 00000001c8f2e000 CR4: 00000000001606f0
DR0: 0000000020000000 DR1: 0000000020000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600
Stack:
 ffffffff84c4f0c8
c ffff8801db307fe8
c ffffffff83a063ba
c ffffffff84c4f0c8
c
 ffff8801d9a87d98
c ffffffff83a03f90
c ffff8801d9a87ce8
c <EOI> 
c 0000000000000000
c
 ffffffff84c5f210
c 0000000000000001
c 0000000000000000
c ffff8801d9a87d98
c
Call Trace:
 <IRQ> 
d [<ffffffff83a063ba>] smp_reschedule_interrupt+0xa/0x90 arch/x86/kernel/smp.c:267
 [<ffffffff83a03f90>] reschedule_interrupt+0xa0/0xb0 arch/x86/entry/entry_64.S:671
 <EOI> 
d [<ffffffff83a008c6>] ? native_safe_halt+0x6/0x10 arch/x86/include/asm/irqflags.h:55
 [<ffffffff839fff05>] arch_safe_halt arch/x86/include/asm/paravirt.h:104 [inline]
 [<ffffffff839fff05>] default_idle+0x55/0x360 arch/x86/kernel/process.c:437
 [<ffffffff8106ae20>] arch_cpu_idle+0x10/0x20 arch/x86/kernel/process.c:428
 [<ffffffff83a00d25>] default_idle_call+0x45/0x60 kernel/sched/idle.c:97
 [<ffffffff81225495>] cpuidle_idle_call kernel/sched/idle.c:155 [inline]
 [<ffffffff81225495>] cpu_idle_loop kernel/sched/idle.c:248 [inline]
 [<ffffffff81225495>] cpu_startup_entry+0x2b5/0x380 kernel/sched/idle.c:303
 [<ffffffff810af308>] start_secondary+0x328/0x400 arch/x86/kernel/smpboot.c:251
Code: 
c53 
ce8 
c46 
cfa 
c13 
c00 
c48 
cb8 
c00 
c00 
c00 
c00 
c00 
cfc 
cff 
cdf 
c65 
c48 
c8b 
c1c 
c25 
cc0 
c7d 
c01 
c00 
c48 
c8d 
cbb 
c20 
c05 
c00 
c00 
c48 
c89 
cfa 
c48 
cc1 
cea 
c03 
c0f 
cb6 
c04 
c02 
c<84> 
cc0 
c74 
c08 
c3c 
c03 
c0f 
c8e 
c86 
c00 
c00 
c00 
c8b 
c83 
c20 
c05 
c00 
c00 
c85 
cc0 
c75 
c