INFO: task syz-executor0:8859 blocked for more than 140 seconds.
      Not tainted 4.19.0-rc7+ #50
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor0   D18920  8859      1 0x00000004
Call Trace:
 context_switch kernel/sched/core.c:2825 [inline]
 __schedule+0x86c/0x1ed0 kernel/sched/core.c:3473
 schedule+0xfe/0x460 kernel/sched/core.c:3517
 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3575
 __mutex_lock_common kernel/locking/mutex.c:1002 [inline]
 __mutex_lock+0xbe7/0x1700 kernel/locking/mutex.c:1072
 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1087
 vfat_lookup+0xf1/0x640 fs/fat/namei_vfat.c:709
 __lookup_slow+0x2b5/0x540 fs/namei.c:1671
 lookup_slow+0x57/0x80 fs/namei.c:1688
 walk_component+0x92b/0x25c0 fs/namei.c:1810
 link_path_walk.part.40+0xa61/0x1530 fs/namei.c:2141
 link_path_walk fs/namei.c:2072 [inline]
 path_openat+0x270/0x5160 fs/namei.c:3533
 do_filp_open+0x255/0x380 fs/namei.c:3564
 do_sys_open+0x568/0x700 fs/open.c:1063
 __do_sys_open fs/open.c:1081 [inline]
 __se_sys_open fs/open.c:1076 [inline]
 __x64_sys_open+0x7e/0xc0 fs/open.c:1076
 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x4555a0
Code: Bad RIP value.
RSP: 002b:00007fffae9fcf50 EFLAGS: 00000206 ORIG_RAX: 0000000000000002
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00000000004555a0
RDX: 0000000000000000 RSI: 0000000000090800 RDI: 00000000004bc2ce
RBP: 000000000000082a R08: 0000000000000001 R09: 0000000001dd6940
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000
R13: 000000000007e104 R14: 0000000000000277 R15: 0000000000000000
INFO: lockdep is turned off.
NMI backtrace for cpu 0
CPU: 0 PID: 982 Comm: khungtaskd Not tainted 4.19.0-rc7+ #50
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+0x1c4/0x2b4 lib/dump_stack.c:113
 nmi_cpu_backtrace.cold.3+0x63/0xa2 lib/nmi_backtrace.c:101
 nmi_trigger_cpumask_backtrace+0x1b3/0x1ed lib/nmi_backtrace.c:62
 arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:38
 trigger_all_cpu_backtrace include/linux/nmi.h:144 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:204 [inline]
 watchdog+0xb3e/0x1050 kernel/hung_task.c:265
 kthread+0x35a/0x420 kernel/kthread.c:246
 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:413
Sending NMI from CPU 0 to CPUs 1:
INFO: NMI handler (nmi_cpu_backtrace_handler) took too long to run: 1.910 msecs
NMI backtrace for cpu 1
CPU: 1 PID: 23869 Comm: syz-executor0 Not tainted 4.19.0-rc7+ #50
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:__sanitizer_cov_trace_const_cmp4+0x0/0x20 kernel/kcov.c:183
Code: a6 fe ff ff 5d c3 0f 1f 40 00 55 0f b7 d6 0f b7 f7 bf 03 00 00 00 48 89 e5 48 8b 4d 08 e8 88 fe ff ff 5d c3 66 0f 1f 44 00 00 <55> 89 f2 89 fe bf 05 00 00 00 48 89 e5 48 8b 4d 08 e8 6a fe ff ff
RSP: 0018:ffff880178fb63c0 EFLAGS: 00000246
RAX: 0000000000000004 RBX: 0000000000000002 RCX: 0000000000000004
RDX: 0000000000000000 RSI: 0000000000000002 RDI: 0000000000000000
RBP: ffff880178fb66f8 R08: fffff94000d6a45f R09: fffff94000d6a45e
R10: fffff94000d6a45e R11: ffffea0006b522f7 R12: 1ffff1002f1f6c92
R13: ffff880178fb66d0 R14: 0000000000000002 R15: dffffc0000000000
FS:  0000000001dd6940(0000) GS:ffff8801daf00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffffff600400 CR3: 00000001d26cc000 CR4: 00000000001426e0
Call Trace:
 pagecache_get_page+0x12f/0xf00 mm/filemap.c:1541
 find_or_create_page include/linux/pagemap.h:322 [inline]
 grow_dev_page fs/buffer.c:947 [inline]
 grow_buffers fs/buffer.c:1016 [inline]
 __getblk_slow fs/buffer.c:1043 [inline]
 __getblk_gfp+0x3b0/0xd50 fs/buffer.c:1320
 __bread_gfp+0x2d/0x300 fs/buffer.c:1354
 sb_bread include/linux/buffer_head.h:307 [inline]
 fat__get_entry+0x5a6/0xa40 fs/fat/dir.c:101
 fat_get_entry fs/fat/dir.c:129 [inline]
 fat_search_long+0x33b/0x1570 fs/fat/dir.c:477
 vfat_find+0x16d/0x1a0 fs/fat/namei_vfat.c:697
 vfat_lookup+0x107/0x640 fs/fat/namei_vfat.c:711
 __lookup_slow+0x2b5/0x540 fs/namei.c:1671
 lookup_slow+0x57/0x80 fs/namei.c:1688
 walk_component+0x92b/0x25c0 fs/namei.c:1810
 link_path_walk.part.40+0xa61/0x1530 fs/namei.c:2141
 link_path_walk fs/namei.c:2072 [inline]
 path_openat+0x270/0x5160 fs/namei.c:3533
 do_filp_open+0x255/0x380 fs/namei.c:3564
 do_sys_open+0x568/0x700 fs/open.c:1063
 __do_sys_open fs/open.c:1081 [inline]
 __se_sys_open fs/open.c:1076 [inline]
 __x64_sys_open+0x7e/0xc0 fs/open.c:1076
 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x4111b0
Code: 01 f0 ff ff 0f 83 e0 17 00 00 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 83 3d fd 4d 63 00 00 75 14 b8 02 00 00 00 0f 05 <48> 3d 01 f0 ff ff 0f 83 b4 17 00 00 c3 48 83 ec 08 e8 8a fa ff ff
RSP: 002b:00007fffae9fcae8 EFLAGS: 00000246 ORIG_RAX: 0000000000000002
RAX: ffffffffffffffda RBX: 00007fffae9fcb11 RCX: 00000000004111b0
RDX: 00007fffae9fcb16 RSI: 0000000000080001 RDI: 00000000004bc3d8
RBP: 00007fffae9fcb10 R08: 0000000000000000 R09: 0000000000000001
R10: 0000000000000075 R11: 0000000000000246 R12: 00000000004bc3d8
R13: 0000000000000000 R14: 0000000000000277 R15: 0000000000000000