kasan: CONFIG_KASAN_INLINE enabled
kasan: GPF could be caused by NULL-ptr deref or user memory access
general protection fault: 0000 [#1] SMP KASAN
Dumping ftrace buffer:
   (ftrace buffer empty)
Modules linked in:
CPU: 0 PID: 8434 Comm: syz-executor4 Not tainted 4.15.0-rc8+ #196
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:strlen+0x1f/0xa0 lib/string.c:479
RSP: 0018:ffff8801bc9a7820 EFLAGS: 00010282
RAX: 0000000041b58ab3 RBX: ffff8801cab16b40 RCX: 000000000836b156
RDX: dffffc0000000000 RSI: ffffc90001f85000 RDI: 0000000041b58ab3
RBP: ffff8801bc9a7838 R08: 1ffff10037934e6d R09: 0000000000000005
R10: ffff8801bc9a7828 R11: 0000000000000001 R12: ffff8801bc9a7958
R13: 0000000041b58ab3 R14: 0000000000000040 R15: 1ffff10037934f0f
FS:  00007f3d0c522700(0000) GS:ffff8801db200000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000020f7c000 CR3: 00000001c28ea002 CR4: 00000000001606f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 strlen include/linux/string.h:266 [inline]
 netlink_ack+0x120/0xa10 net/netlink/af_netlink.c:2357
 netlink_rcv_skb+0x2d1/0x400 net/netlink/af_netlink.c:2448
 genl_rcv+0x28/0x40 net/netlink/genetlink.c:635
 netlink_unicast_kernel net/netlink/af_netlink.c:1308 [inline]
 netlink_unicast+0x4c4/0x6b0 net/netlink/af_netlink.c:1334
 netlink_sendmsg+0xa4a/0xe60 net/netlink/af_netlink.c:1897
 sock_sendmsg_nosec net/socket.c:630 [inline]
 sock_sendmsg+0xca/0x110 net/socket.c:640
 sock_write_iter+0x31a/0x5d0 net/socket.c:909
 call_write_iter include/linux/fs.h:1772 [inline]
 new_sync_write fs/read_write.c:469 [inline]
 __vfs_write+0x684/0x970 fs/read_write.c:482
 vfs_write+0x189/0x510 fs/read_write.c:544
 SYSC_write fs/read_write.c:589 [inline]
 SyS_write+0xef/0x220 fs/read_write.c:581
 entry_SYSCALL_64_fastpath+0x29/0xa0
RIP: 0033:0x452e99
RSP: 002b:00007f3d0c521c58 EFLAGS: 00000212 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 000000000071bea0 RCX: 0000000000452e99
RDX: 0000000000000070 RSI: 0000000020f7c000 RDI: 0000000000000013
RBP: 000000000000000b R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000212 R12: 00000000006ee1a8
R13: 00000000ffffffff R14: 00007f3d0c5226d4 R15: 0000000000000000
Code: 37 ff ff ff 0f 1f 84 00 00 00 00 00 55 48 89 f9 48 ba 00 00 00 00 00 fc ff df 48 c1 e9 03 48 89 f8 48 89 e5 41 54 53 48 83 ec 08 <0f> b6 14 11 48 89 f9 83 e1 07 38 ca 7f 04 84 d2 75 4b 80 38 00 
RIP: strlen+0x1f/0xa0 lib/string.c:479 RSP: ffff8801bc9a7820
---[ end trace 1a6a39d689bd184e ]---