==================================================================
BUG: KASAN: use-after-free in __list_del_entry_valid+0xf1/0x100 lib/list_debug.c:51
Read of size 8 at addr ffff880183d17b70 by task syz-executor0/23150

CPU: 0 PID: 23150 Comm: syz-executor0 Not tainted 4.20.0-rc1-next-20181109+ #110
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+0x244/0x39d lib/dump_stack.c:113
 print_address_description.cold.7+0x9/0x1ff mm/kasan/report.c:256
 kasan_report_error mm/kasan/report.c:354 [inline]
 kasan_report.cold.8+0x242/0x309 mm/kasan/report.c:412
 __asan_report_load8_noabort+0x14/0x20 mm/kasan/report.c:433
 __list_del_entry_valid+0xf1/0x100 lib/list_debug.c:51
 __list_del_entry include/linux/list.h:117 [inline]
 list_del_init include/linux/list.h:159 [inline]
 __locks_delete_block fs/locks.c:683 [inline]
 locks_delete_block+0xce/0x3d0 fs/locks.c:716
 locks_mandatory_area+0x48b/0x6a0 fs/locks.c:1398
 rw_verify_area+0x2f2/0x360 fs/read_write.c:386
 vfs_write+0x149/0x560 fs/read_write.c:544
 ksys_write+0x101/0x260 fs/read_write.c:598
 __do_sys_write fs/read_write.c:610 [inline]
 __se_sys_write fs/read_write.c:607 [inline]
 __x64_sys_write+0x73/0xb0 fs/read_write.c:607
 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x457569
Code: fd b3 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 cb b3 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007f935232dc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000457569
RDX: 0000000000000018 RSI: 0000000020000080 RDI: 0000000000000004
RBP: 000000000072c040 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f935232e6d4
R13: 00000000004c5609 R14: 00000000004d9500 R15: 00000000ffffffff

kasan: CONFIG_KASAN_INLINE enabled
kasan: GPF could be caused by NULL-ptr deref or user memory access
general protection fault: 0000 [#1] PREEMPT SMP KASAN
CPU: 0 PID: 23150 Comm: syz-executor0 Not tainted 4.20.0-rc1-next-20181109+ #110
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:print_address_description.cold.7+0x111/0x1ff mm/kasan/report.c:261
Code: ff ff a8 01 0f 84 e5 00 00 00 48 83 e8 01 48 8b 00 f6 c4 02 0f 84 66 ff ff ff 4d 8b 74 24 18 48 89 d8 49 89 dd 49 8b 4c 24 28 <41> 8b 7e 14 48 29 c8 48 99 48 f7 ff 41 8b 46 24 49 29 d5 83 e8 01
RSP: 0018:ffff88017a6df8e0 EFLAGS: 00010002
RAX: ffff880183d17b70 RBX: ffff880183d17b70 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffffffff8165ba15 RDI: 0000000000000005
RBP: ffff88017a6df908 R08: ffff8801bab80540 R09: ffffed003b5c3ef8
R10: ffffed003b5c3ef8 R11: ffff8801dae1f7c7 R12: ffffea00060f45c0
R13: ffff880183d17b70 R14: dead000000000400 R15: ffff88017a6dfa58
FS:  00007f935232e700(0000) GS:ffff8801dae00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f49ebb42db8 CR3: 00000001be545000 CR4: 00000000001426f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 kasan_report_error mm/kasan/report.c:354 [inline]
 kasan_report.cold.8+0x242/0x309 mm/kasan/report.c:412
 __asan_report_load8_noabort+0x14/0x20 mm/kasan/report.c:433
 __list_del_entry_valid+0xf1/0x100 lib/list_debug.c:51
 __list_del_entry include/linux/list.h:117 [inline]
 list_del_init include/linux/list.h:159 [inline]
 __locks_delete_block fs/locks.c:683 [inline]
 locks_delete_block+0xce/0x3d0 fs/locks.c:716
 locks_mandatory_area+0x48b/0x6a0 fs/locks.c:1398
 rw_verify_area+0x2f2/0x360 fs/read_write.c:386
 vfs_write+0x149/0x560 fs/read_write.c:544
 ksys_write+0x101/0x260 fs/read_write.c:598
 __do_sys_write fs/read_write.c:610 [inline]
 __se_sys_write fs/read_write.c:607 [inline]
 __x64_sys_write+0x73/0xb0 fs/read_write.c:607
 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x457569
Code: fd b3 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 cb b3 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007f935232dc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000457569
RDX: 0000000000000018 RSI: 0000000020000080 RDI: 0000000000000004
RBP: 000000000072c040 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f935232e6d4
R13: 00000000004c5609 R14: 00000000004d9500 R15: 00000000ffffffff
Modules linked in:
---[ end trace 086b15867e8a958d ]---
RIP: 0010:print_address_description.cold.7+0x111/0x1ff mm/kasan/report.c:261
Code: ff ff a8 01 0f 84 e5 00 00 00 48 83 e8 01 48 8b 00 f6 c4 02 0f 84 66 ff ff ff 4d 8b 74 24 18 48 89 d8 49 89 dd 49 8b 4c 24 28 <41> 8b 7e 14 48 29 c8 48 99 48 f7 ff 41 8b 46 24 49 29 d5 83 e8 01
RSP: 0018:ffff88017a6df8e0 EFLAGS: 00010002
RAX: ffff880183d17b70 RBX: ffff880183d17b70 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffffffff8165ba15 RDI: 0000000000000005
RBP: ffff88017a6df908 R08: ffff8801bab80540 R09: ffffed003b5c3ef8
R10: ffffed003b5c3ef8 R11: ffff8801dae1f7c7 R12: ffffea00060f45c0
R13: ffff880183d17b70 R14: dead000000000400 R15: ffff88017a6dfa58
FS:  00007f935232e700(0000) GS:ffff8801dae00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f49ebb42db8 CR3: 00000001be545000 CR4: 00000000001426f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400