netlink: 3 bytes leftover after parsing attributes in process `syz-executor3'.
------------[ cut here ]------------
kernel BUG at mm/usercopy.c:72!
invalid opcode: 0000 [#1] SMP KASAN
Dumping ftrace buffer:
   (ftrace buffer empty)
Modules linked in:
CPU: 0 PID: 26072 Comm: syz-executor4 Not tainted 4.15.0-rc5+ #176
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:report_usercopy mm/usercopy.c:64 [inline]
RIP: 0010:__check_object_size+0x3a2/0x4f0 mm/usercopy.c:264
RSP: 0018:ffff8801c562fa30 EFLAGS: 00010286
RAX: 0000000000000062 RBX: ffffffff8592bb60 RCX: 0000000000000000
RDX: 0000000000000062 RSI: ffffc90002b95000 RDI: ffffed0038ac5f3a
RBP: ffff8801c562fb20 R08: 0000000000000000 R09: 0000000000000000
R10: 000000009d9a4930 R11: 0000000000000000 R12: ffffffff8592bb20
R13: ffff8801cb9b6dd0 R14: 00000000000003e8 R15: ffffea00072e6d80
FS:  00007f1284ece700(0000) GS:ffff8801db200000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffd88132f98 CR3: 00000001cf013006 CR4: 00000000001606f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 check_object_size include/linux/thread_info.h:112 [inline]
 check_copy_size include/linux/thread_info.h:143 [inline]
 copy_from_user include/linux/uaccess.h:146 [inline]
 ___sys_sendmsg+0x59c/0x8b0 net/socket.c:1995
 __sys_sendmsg+0xe5/0x210 net/socket.c:2052
 SYSC_sendmsg net/socket.c:2063 [inline]
 SyS_sendmsg+0x2d/0x50 net/socket.c:2059
 entry_SYSCALL_64_fastpath+0x23/0x9a
RIP: 0033:0x452ac9
RSP: 002b:00007f1284ecdc58 EFLAGS: 00000212 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 000000000071bea0 RCX: 0000000000452ac9
RDX: 0000000000008000 RSI: 0000000020260fc8 RDI: 0000000000000013
RBP: 000000000000054e R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000212 R12: 00000000006f5ff0
R13: 00000000ffffffff R14: 00007f1284ece6d4 R15: 0000000000000000
Code: 48 0f 44 da e8 70 5b c0 ff 48 8b 85 28 ff ff ff 4d 89 f1 4c 89 e9 4c 89 e2 48 89 de 48 c7 c7 20 bc 92 85 49 89 c0 e8 e6 10 aa ff <0f> 0b 48 c7 c0 e0 b9 92 85 eb 96 48 c7 c0 20 ba 92 85 eb 8d 48 
RIP: report_usercopy mm/usercopy.c:64 [inline] RSP: ffff8801c562fa30
RIP: __check_object_size+0x3a2/0x4f0 mm/usercopy.c:264 RSP: ffff8801c562fa30
---[ end trace 6660fbf3f8a1e92d ]---
Kernel panic - not syncing: Fatal exception
Dumping ftrace buffer:
   (ftrace buffer empty)
Kernel Offset: disabled
Rebooting in 86400 seconds..