netlink: 'syz-executor1': attribute type 1 has an invalid length.
netlink: 4 bytes leftover after parsing attributes in process `syz-executor1'.
netlink: 'syz-executor3': attribute type 1 has an invalid length.
netlink: 4 bytes leftover after parsing attributes in process `syz-executor3'.
==================================================================
BUG: KASAN: use-after-free in __list_del_entry_valid+0xf1/0x100 lib/list_debug.c:51
Read of size 8 at addr ffff8801c1d5f950 by task syz-executor4/22275

CPU: 0 PID: 22275 Comm: syz-executor4 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
 do_iter_write+0x101/0x5f0 fs/read_write.c:954
 vfs_writev+0x1f1/0x360 fs/read_write.c:1004
 do_pwritev+0x1cc/0x280 fs/read_write.c:1093
 __do_sys_pwritev fs/read_write.c:1140 [inline]
 __se_sys_pwritev fs/read_write.c:1135 [inline]
 __x64_sys_pwritev+0x9a/0xf0 fs/read_write.c:1135
 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:00007fb21e924c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000128
RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 0000000000457569
RDX: 0000000000000001 RSI: 0000000020000240 RDI: 0000000000000004
RBP: 000000000072c0e0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fb21e9256d4
R13: 00000000004c38e4 R14: 00000000004d5d88 R15: 00000000ffffffff

The buggy address belongs to the page:
page:ffffea00070757c0 count:0 mapcount:0 mapping:0000000000000000 index:0x0
flags: 0x2fffc0000000000()
raw: 02fffc0000000000 0000000000000000 ffffffff07070101 0000000000000000
raw: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8801c1d5f800: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff8801c1d5f880: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff8801c1d5f900: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                                                 ^
 ffff8801c1d5f980: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff8801c1d5fa00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
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