INFO: task syz-executor0:28096 blocked for more than 120 seconds.
      Not tainted 4.9.105-ga56900fa #39
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor0   D28312 28096  12030 0x00000004
 ffff8801c62a1800 0000000000000000 ffff8801c53b2f40 ffffffff84629800
 ffff8801db221c18 ffff880186767ac8 ffffffff839e8c1d ffff880186767ae8
 ffff880183c060c8 0000000000000000 0000000000000000 ffff8801db2224e8
Call Trace:
 [<ffffffff839ea21f>] schedule+0x7f/0x1b0 kernel/sched/core.c:3557
 [<ffffffff839f5858>] __rwsem_down_write_failed_common kernel/locking/rwsem-xadd.c:526 [inline]
 [<ffffffff839f5858>] rwsem_down_write_failed+0x598/0x990 kernel/locking/rwsem-xadd.c:555
 [<ffffffff81ee8487>] call_rwsem_down_write_failed+0x17/0x30 arch/x86/lib/rwsem.S:105
 [<ffffffff8122c760>] __down_write arch/x86/include/asm/rwsem.h:125 [inline]
 [<ffffffff8122c760>] down_write_nested+0x60/0xa0 kernel/locking/rwsem.c:174
 [<ffffffff815aa28a>] inode_lock_nested include/linux/fs.h:801 [inline]
 [<ffffffff815aa28a>] filename_create+0x17a/0x490 fs/namei.c:3639
 [<ffffffff815ac961>] user_path_create fs/namei.c:3697 [inline]
 [<ffffffff815ac961>] SYSC_mkdirat fs/namei.c:3841 [inline]
 [<ffffffff815ac961>] SyS_mkdirat fs/namei.c:3833 [inline]
 [<ffffffff815ac961>] SYSC_mkdir fs/namei.c:3860 [inline]
 [<ffffffff815ac961>] SyS_mkdir+0xb1/0x260 fs/namei.c:3858
 [<ffffffff81006316>] do_syscall_64+0x1a6/0x490 arch/x86/entry/common.c:282
 [<ffffffff839f9b13>] 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: [<ffffffff81366b9c>] check_hung_uninterruptible_tasks kernel/hung_task.c:168 [inline]
 #0:  (rcu_read_lock){......}, at: [<ffffffff81366b9c>] watchdog+0x11c/0xa20 kernel/hung_task.c:239
 #1:  (tasklist_lock){.+.?..}, at: [<ffffffff81426180>] debug_show_all_locks+0x79/0x218 kernel/locking/lockdep.c:4336
2 locks held by getty/3775:
 #0:  (&tty->ldisc_sem){++++++}, at: [<ffffffff839f7cc2>] ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:367
 #1:  (&ldata->atomic_read_lock){+.+...}, at: [<ffffffff82120062>] n_tty_read+0x202/0x16e0 drivers/tty/n_tty.c:2133
2 locks held by syz-executor0/28096:
 #0:  (sb_writers#21){.+.+.+}, at: [<ffffffff815e0c9f>] sb_start_write include/linux/fs.h:1573 [inline]
 #0:  (sb_writers#21){.+.+.+}, at: [<ffffffff815e0c9f>] mnt_want_write+0x3f/0xb0 fs/namespace.c:391
 #1:  (&sb->s_type->i_mutex_key#21/1){+.+.+.}, at: [<ffffffff815aa28a>] inode_lock_nested include/linux/fs.h:801 [inline]
 #1:  (&sb->s_type->i_mutex_key#21/1){+.+.+.}, at: [<ffffffff815aa28a>] filename_create+0x17a/0x490 fs/namei.c:3639

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

NMI backtrace for cpu 0
CPU: 0 PID: 519 Comm: khungtaskd Not tainted 4.9.105-ga56900fa #39
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
 ffff8801d8fafd08 ffffffff81eb41a9 0000000000000000 0000000000000000
 0000000000000000 0000000000000001 ffffffff810b96a0 ffff8801d8fafd40
 ffffffff81ebf4a7 0000000000000000 0000000000000000 0000000000000003
Call Trace:
 [<ffffffff81eb41a9>] __dump_stack lib/dump_stack.c:15 [inline]
 [<ffffffff81eb41a9>] dump_stack+0xc1/0x128 lib/dump_stack.c:51
 [<ffffffff81ebf4a7>] nmi_cpu_backtrace.cold.2+0x48/0x87 lib/nmi_backtrace.c:99
 [<ffffffff81ebf43a>] nmi_trigger_cpumask_backtrace+0x12a/0x14f lib/nmi_backtrace.c:60
 [<ffffffff810b97a4>] arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:37
 [<ffffffff81367134>] trigger_all_cpu_backtrace include/linux/nmi.h:58 [inline]
 [<ffffffff81367134>] check_hung_task kernel/hung_task.c:125 [inline]
 [<ffffffff81367134>] check_hung_uninterruptible_tasks kernel/hung_task.c:182 [inline]
 [<ffffffff81367134>] watchdog+0x6b4/0xa20 kernel/hung_task.c:239
 [<ffffffff8119d04d>] kthread+0x26d/0x300 kernel/kthread.c:211
 [<ffffffff839f9cdc>] 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: 28080 Comm: syz-executor0 Not tainted 4.9.105-ga56900fa #39
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
task: ffff880187748000 task.stack: ffff8801d0538000
RIP: 0010:[<ffffffff8135eeb0>] 
c [<ffffffff8135eeb0>] __sanitizer_cov_trace_pc+0x0/0x50
RSP: 0018:ffff8801db307d98  EFLAGS: 00000097
RAX: 0000000000010002 RBX: 0000000000000001 RCX: 1ffffffff0886481
RDX: 0000000000000000 RSI: ffffffff81f1bc0b RDI: ffffffff85b2d700
RBP: ffff8801db307da0 R08: ffff8801877489b0 R09: 0000000000000001
R10: 0000000000000000 R11: 1ffff10030ee9131 R12: ffffffff813f9a80
R13: ffff8801db31c900 R14: dffffc0000000000 R15: dffffc0000000000
FS:  00007f18474e1700(0000) GS:ffff8801db300000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fbdf49bf000 CR3: 00000001d6e22000 CR4: 00000000001606f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Stack:
 ffffffff81f1bd49
c ffff8801db307dd0
c ffffffff812845dc
c ffff8801db307dd0
c
 ffffffff84870a60
c ffffffff813f9a80
c ffff8801db31c900
c ffff8801db307de8
c
 ffffffff8127c526
c ffff8801ba062bc8
c ffff8801db307f20
c ffffffff812a527a
c
Call Trace:
 [<ffffffff812845dc>] rcu_lockdep_current_cpu_online+0x3c/0x140 kernel/rcu/tree.c:1105
 [<ffffffff8127c526>] rcu_read_lock_sched_held+0x96/0x120 kernel/rcu/update.c:109
 [<ffffffff812a527a>] trace_hrtimer_expire_entry include/trace/events/timer.h:212 [inline]
 [<ffffffff812a527a>] __run_hrtimer kernel/time/hrtimer.c:1254 [inline]
 [<ffffffff812a527a>] __hrtimer_run_queues+0xa6a/0xe50 kernel/time/hrtimer.c:1319
 [<ffffffff812a60c1>] hrtimer_interrupt+0x1b1/0x430 kernel/time/hrtimer.c:1353
 [<ffffffff810b1e54>] local_apic_timer_interrupt+0x74/0xa0 arch/x86/kernel/apic/apic.c:935
 [<ffffffff839ff2dc>] smp_apic_timer_interrupt+0x7c/0xa0 arch/x86/kernel/apic/apic.c:959
 [<ffffffff839fb470>] apic_timer_interrupt+0xa0/0xb0 arch/x86/entry/entry_64.S:648
 <EOI> 
d [<ffffffff81ec3f56>] ? radix_tree_lookup_slot+0x46/0xc0 lib/radix-tree.c:722
 [<ffffffff81438ffe>] find_get_entry+0x8e/0x540 mm/filemap.c:1095
 [<ffffffff8143a3eb>] pagecache_get_page+0x4b/0x720 mm/filemap.c:1203
 [<ffffffff81625669>] find_or_create_page include/linux/pagemap.h:309 [inline]
 [<ffffffff81625669>] grow_dev_page fs/buffer.c:1005 [inline]
 [<ffffffff81625669>] grow_buffers fs/buffer.c:1078 [inline]
 [<ffffffff81625669>] __getblk_slow fs/buffer.c:1105 [inline]
 [<ffffffff81625669>] __getblk_gfp+0x249/0x710 fs/buffer.c:1386
 [<ffffffff81628f4d>] __bread_gfp+0x2d/0x270 fs/buffer.c:1420
 [<ffffffff818b7178>] sb_bread include/linux/buffer_head.h:300 [inline]
 [<ffffffff818b7178>] fat__get_entry+0x4c8/0x8f0 fs/fat/dir.c:100
 [<ffffffff818b9e01>] fat_get_entry fs/fat/dir.c:128 [inline]
 [<ffffffff818b9e01>] fat_get_short_entry+0x131/0x2a0 fs/fat/dir.c:876
 [<ffffffff818ba35d>] fat_scan+0xfd/0x340 fs/fat/dir.c:961
 [<ffffffff818e1969>] msdos_find+0xf9/0x2d0 fs/fat/namei_msdos.c:128
 [<ffffffff818e2285>] msdos_lookup+0x135/0x250 fs/fat/namei_msdos.c:208
 [<ffffffff815940bc>] lookup_real fs/namei.c:1522 [inline]
 [<ffffffff815940bc>] __lookup_hash+0x11c/0x190 fs/namei.c:1542
 [<ffffffff815aa2b6>] filename_create+0x1a6/0x490 fs/namei.c:3640
 [<ffffffff815ac961>] user_path_create fs/namei.c:3697 [inline]
 [<ffffffff815ac961>] SYSC_mkdirat fs/namei.c:3841 [inline]
 [<ffffffff815ac961>] SyS_mkdirat fs/namei.c:3833 [inline]
 [<ffffffff815ac961>] SYSC_mkdir fs/namei.c:3860 [inline]
 [<ffffffff815ac961>] SyS_mkdir+0xb1/0x260 fs/namei.c:3858
 [<ffffffff81006316>] do_syscall_64+0x1a6/0x490 arch/x86/entry/common.c:282
 [<ffffffff839f9b13>] entry_SYSCALL_64_after_swapgs+0x5d/0xdb
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