Oops: general protection fault, probably for non-canonical address 0xdffffc0000000005: 0000 [#1] SMP KASAN PTI
KASAN: null-ptr-deref in range [0x0000000000000028-0x000000000000002f]
CPU: 1 UID: 0 PID: 4741 Comm: syz.2.13511 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
RIP: 0010:handshake_complete+0x36/0x350
Code: 54 53 48 83 ec 10 48 89 54 24 08 89 f5 49 89 ff 49 bd 00 00 00 00 00 fc ff df e8 05 d1 59 f6 49 8d 5f 28 48 89 d8 48 c1 e8 03 <42> 80 3c 28 00 74 08 48 89 df e8 1b 77 c1 f6 48 8b 1b 4c 8d 63 30
RSP: 0018:ffffc90003f472e0 EFLAGS: 00010206
RAX: 0000000000000005 RBX: 0000000000000028 RCX: 0000000000080000
RDX: ffffc90023ea6000 RSI: 000000000000017c RDI: 000000000000017d
RBP: 00000000fffffffb R08: ffff888175125883 R09: 1ffff1102ea24b10
R10: dffffc0000000000 R11: ffffed102ea24b11 R12: ffff88816b5a7c10
R13: dffffc0000000000 R14: dffffc0000000000 R15: 0000000000000000
FS:  00007fa6770986c0(0000) GS:ffff8882a9a1f000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fa677097ff8 CR3: 000000019a5d6000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 handshake_nl_accept_doit+0x3f1/0x820
 genl_family_rcv_msg_doit+0x22a/0x330
 genl_rcv_msg+0x61c/0x7a0
 netlink_rcv_skb+0x232/0x4b0
 genl_rcv+0x28/0x40
 netlink_unicast+0x80f/0x9b0
 netlink_sendmsg+0x813/0xb40
 __sock_sendmsg+0x21c/0x270
 ____sys_sendmsg+0x4d7/0x810
 ___sys_sendmsg+0x2a5/0x360
 __x64_sys_sendmsg+0x1bd/0x2a0
 do_syscall_64+0xf0/0xf80
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fa67619acb9
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 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 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fa677098028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007fa676405fa0 RCX: 00007fa67619acb9
RDX: 0000000000000000 RSI: 0000200000000000 RDI: 0000000000000003
RBP: 00007fa676208bf7 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fa676406038 R14: 00007fa676405fa0 R15: 00007ffd42b8b4c8
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:handshake_complete+0x36/0x350
Code: 54 53 48 83 ec 10 48 89 54 24 08 89 f5 49 89 ff 49 bd 00 00 00 00 00 fc ff df e8 05 d1 59 f6 49 8d 5f 28 48 89 d8 48 c1 e8 03 <42> 80 3c 28 00 74 08 48 89 df e8 1b 77 c1 f6 48 8b 1b 4c 8d 63 30
RSP: 0018:ffffc90003f472e0 EFLAGS: 00010206
RAX: 0000000000000005 RBX: 0000000000000028 RCX: 0000000000080000
RDX: ffffc90023ea6000 RSI: 000000000000017c RDI: 000000000000017d
RBP: 00000000fffffffb R08: ffff888175125883 R09: 1ffff1102ea24b10
R10: dffffc0000000000 R11: ffffed102ea24b11 R12: ffff88816b5a7c10
R13: dffffc0000000000 R14: dffffc0000000000 R15: 0000000000000000
FS:  00007fa6770986c0(0000) GS:ffff8882a9a1f000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fa677097ff8 CR3: 000000019a5d6000 CR4: 00000000000006f0
