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: 4238 Comm: syz-executor1 Not tainted 4.13.0-rc5-next-20170816+ #4
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
task: ffff88003d168340 task.stack: ffff880039f78000
RIP: 0010:fib_dump_info+0x3aa/0x1470 net/ipv4/fib_semantics.c:1315
RSP: 0018:ffff880039f7ec08 EFLAGS: 00010206
RAX: dffffc0000000000 RBX: 00000000000000fe RCX: ffffc90001e61000
RDX: 0000000000000006 RSI: 0000000000000002 RDI: 0000000000000030
RBP: ffff880039f7ee60 R08: ffffed0006ee2861 R09: ffffed0006ee2861
R10: 0000000000000001 R11: ffffed0006ee2860 R12: ffff8800377142f5
R13: 0000000000000000 R14: ffff8800377142e4 R15: ffff880036f53280
FS:  00007f71cb823700(0000) GS:ffff88003ec00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000020d24fd7 CR3: 000000006b4c0000 CR4: 00000000000026f0
Call Trace:
 inet_rtm_getroute+0xf9c/0x2d60 net/ipv4/route.c:2773
 rtnetlink_rcv_msg+0x733/0x1090 net/core/rtnetlink.c:4246
 netlink_rcv_skb+0x216/0x440 net/netlink/af_netlink.c:2397
 rtnetlink_rcv+0x1c/0x20 net/core/rtnetlink.c:4258
 netlink_unicast_kernel net/netlink/af_netlink.c:1265 [inline]
 netlink_unicast+0x4e8/0x6f0 net/netlink/af_netlink.c:1291
 netlink_sendmsg+0xa4a/0xe60 net/netlink/af_netlink.c:1854
 sock_sendmsg_nosec net/socket.c:633 [inline]
 sock_sendmsg+0xca/0x110 net/socket.c:643
 sock_write_iter+0x31a/0x5d0 net/socket.c:912
 call_write_iter include/linux/fs.h:1742 [inline]
 do_iter_readv_writev+0x525/0x7f0 fs/read_write.c:650
 do_iter_write+0x154/0x540 fs/read_write.c:929
 vfs_writev+0x18a/0x340 fs/read_write.c:975
 do_writev+0xfc/0x2a0 fs/read_write.c:1011
 SYSC_writev fs/read_write.c:1084 [inline]
 SyS_writev+0x27/0x30 fs/read_write.c:1081
 entry_SYSCALL_64_fastpath+0x1f/0xbe
RIP: 0033:0x446739
RSP: 002b:00007f71cb822c08 EFLAGS: 00000296 ORIG_RAX: 0000000000000014
RAX: ffffffffffffffda RBX: 0000000000000019 RCX: 0000000000446739
RDX: 0000000000000001 RSI: 0000000020268000 RDI: 0000000000000019
RBP: 0000000000708000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000296 R12: 00000000ffffffff
R13: 0000000000000630 R14: 00000000006e26f0 R15: 0000000000000048
Code: 0f b6 b5 e4 fd ff ff 48 8b 85 f0 fd ff ff 40 88 70 17 48 8b 45 28 48 8d 78 30 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <0f> b6 04 02 84 c0 74 08 3c 03 0f 8e 8d 0e 00 00 48 8b 45 28 44 
RIP: fib_dump_info+0x3aa/0x1470 net/ipv4/fib_semantics.c:1315 RSP: ffff880039f7ec08
---[ end trace 4fd0edfd40a365d6 ]---