Use struct sctp_assoc_value instead
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: 14230 Comm: syz-executor6 Not tainted 4.13.0-rc5+ #14
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
task: ffff8801c2278740 task.stack: ffff8801c2fe8000
RIP: 0010:fib_dump_info+0x3aa/0x1470 net/ipv4/fib_semantics.c:1317
RSP: 0018:ffff8801c2feedc0 EFLAGS: 00010206
RAX: dffffc0000000000 RBX: 0000000000000000 RCX: ffffc90003d5f000
RDX: 0000000000000006 RSI: 0000000000000002 RDI: 0000000000000030
RBP: ffff8801c2fef018 R08: ffffed0038e330f1 R09: ffffed0038e330f1
R10: 0000000000000001 R11: ffffed0038e330f0 R12: ffff8801c7198775
R13: 0000000000000000 R14: ffff8801c7198764 R15: ffff8801c9678bc0
FS:  00007feebc564700(0000) GS:ffff8801db200000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000020a2a000 CR3: 00000001c8a5c000 CR4: 00000000001406f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 inet_rtm_getroute+0xf9c/0x2d60 net/ipv4/route.c:2773
 rtnetlink_rcv_msg+0x51c/0x1090 net/core/rtnetlink.c:4234
 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:1743 [inline]
 new_sync_write fs/read_write.c:457 [inline]
 __vfs_write+0x684/0x970 fs/read_write.c:470
 vfs_write+0x189/0x510 fs/read_write.c:518
 SYSC_write fs/read_write.c:565 [inline]
 SyS_write+0xef/0x220 fs/read_write.c:557
 entry_SYSCALL_64_fastpath+0x1f/0xbe
RIP: 0033:0x4512e9
RSP: 002b:00007feebc563c08 EFLAGS: 00000216 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 0000000000718000 RCX: 00000000004512e9
RDX: 0000000000000025 RSI: 0000000020a2a000 RDI: 0000000000000005
RBP: 0000000000000086 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000216 R12: 0000000000000000
R13: 0000000000a6f7ef R14: 00007feebc5649c0 R15: 0000000000000000
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:1317 RSP: ffff8801c2feedc0
---[ end trace 11bdbf16eed5bcbf ]---