Oops: general protection fault, probably for non-canonical address 0xdffffc0000000005: 0000 [#1] SMP KASAN NOPTI
KASAN: null-ptr-deref in range [0x0000000000000028-0x000000000000002f]
CPU: 3 UID: 0 PID: 17672 Comm: syz.4.3463 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
RIP: 0010:handshake_complete+0x31/0x390 net/handshake/request.c:288
Code: 56 41 55 49 89 d5 41 54 41 89 f4 55 53 48 89 fb e8 d4 fc 6f f6 48 8d 7b 28 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 0f 03 00 00 48 8b 6b 28 e8 dc 23 0e 00 48 b8 00
RSP: 0018:ffffc9000c1a74e8 EFLAGS: 00010206
RAX: dffffc0000000000 RBX: 0000000000000000 RCX: ffffc9002beca000
RDX: 0000000000000005 RSI: ffffffff8b4d245c RDI: 0000000000000028
RBP: ffffc9000c1a75b0 R08: 0000000000000000 R09: ffffed100d1cb750
R10: ffff888068e5ba83 R11: 000000000000001e R12: 00000000fffffffb
R13: 0000000000000000 R14: ffff888050ae4680 R15: ffff8880243b2500
FS:  0000000000000000(0000) GS:ffff888097ca8000(0063) knlGS:00000000f540db40
CS:  0010 DS: 002b ES: 002b CR0: 0000000080050033
CR2: 00000000f72c4d88 CR3: 0000000073eeb000 CR4: 0000000000352ef0
DR0: ffffffffffffffff DR1: 00000000000001f8 DR2: 0000000000000083
DR3: ffffffffefffff15 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 handshake_nl_accept_doit+0x2dc/0x910 net/handshake/netlink.c:129
 genl_family_rcv_msg_doit+0x209/0x2f0 net/netlink/genetlink.c:1115
 genl_family_rcv_msg net/netlink/genetlink.c:1195 [inline]
 genl_rcv_msg+0x55c/0x800 net/netlink/genetlink.c:1210
 netlink_rcv_skb+0x158/0x420 net/netlink/af_netlink.c:2552
 genl_rcv+0x28/0x40 net/netlink/genetlink.c:1219
 netlink_unicast_kernel net/netlink/af_netlink.c:1320 [inline]
 netlink_unicast+0x5aa/0x870 net/netlink/af_netlink.c:1346
 netlink_sendmsg+0x8c8/0xdd0 net/netlink/af_netlink.c:1896
 sock_sendmsg_nosec net/socket.c:718 [inline]
 __sock_sendmsg net/socket.c:733 [inline]
 ____sys_sendmsg+0xa5d/0xc30 net/socket.c:2608
 ___sys_sendmsg+0x134/0x1d0 net/socket.c:2662
 __sys_sendmsg+0x16d/0x220 net/socket.c:2694
 do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline]
 __do_fast_syscall_32+0x7c/0x370 arch/x86/entry/syscall_32.c:306
 do_fast_syscall_32+0x32/0x80 arch/x86/entry/syscall_32.c:331
 entry_SYSENTER_compat_after_hwframe+0x84/0x8e
RIP: 0023:0xf701d579
Code: b8 01 10 06 03 74 b4 01 10 07 03 74 b0 01 10 08 03 74 d8 01 00 00 00 00 00 00 00 00 00 00 00 00 00 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 8d b4 26 00 00 00 00 8d b4 26 00 00 00 00
RSP: 002b:00000000f540d55c EFLAGS: 00000296 ORIG_RAX: 0000000000000172
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000080000000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000296 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:handshake_complete+0x31/0x390 net/handshake/request.c:288
Code: 56 41 55 49 89 d5 41 54 41 89 f4 55 53 48 89 fb e8 d4 fc 6f f6 48 8d 7b 28 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 0f 03 00 00 48 8b 6b 28 e8 dc 23 0e 00 48 b8 00
RSP: 0018:ffffc9000c1a74e8 EFLAGS: 00010206
RAX: dffffc0000000000 RBX: 0000000000000000 RCX: ffffc9002beca000
RDX: 0000000000000005 RSI: ffffffff8b4d245c RDI: 0000000000000028
RBP: ffffc9000c1a75b0 R08: 0000000000000000 R09: ffffed100d1cb750
R10: ffff888068e5ba83 R11: 000000000000001e R12: 00000000fffffffb
R13: 0000000000000000 R14: ffff888050ae4680 R15: ffff8880243b2500
FS:  0000000000000000(0000) GS:ffff888097ca8000(0063) knlGS:00000000f540db40
CS:  0010 DS: 002b ES: 002b CR0: 0000000080050033
CR2: 00000000584094c0 CR3: 0000000073eeb000 CR4: 0000000000352ef0
DR0: ffffffffffffffff DR1: 00000000000001f8 DR2: 0000000000000083
DR3: ffffffffefffff15 DR6: 00000000ffff0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
   0:	56                   	push   %rsi
   1:	41 55                	push   %r13
   3:	49 89 d5             	mov    %rdx,%r13
   6:	41 54                	push   %r12
   8:	41 89 f4             	mov    %esi,%r12d
   b:	55                   	push   %rbp
   c:	53                   	push   %rbx
   d:	48 89 fb             	mov    %rdi,%rbx
  10:	e8 d4 fc 6f f6       	call   0xf66ffce9
  15:	48 8d 7b 28          	lea    0x28(%rbx),%rdi
  19:	48 b8 00 00 00 00 00 	movabs $0xdffffc0000000000,%rax
  20:	fc ff df
  23:	48 89 fa             	mov    %rdi,%rdx
  26:	48 c1 ea 03          	shr    $0x3,%rdx
* 2a:	80 3c 02 00          	cmpb   $0x0,(%rdx,%rax,1) <-- trapping instruction
  2e:	0f 85 0f 03 00 00    	jne    0x343
  34:	48 8b 6b 28          	mov    0x28(%rbx),%rbp
  38:	e8 dc 23 0e 00       	call   0xe2419
  3d:	48                   	rex.W
  3e:	b8                   	.byte 0xb8