kasan: CONFIG_KASAN_INLINE enabled
kasan: GPF could be caused by NULL-ptr deref or user memory accessgeneral protection fault: 0000 [#1] PREEMPT SMP KASAN
Dumping ftrace buffer:
   (ftrace buffer empty)
Modules linked in:
CPU: 1 PID: 9956 Comm: syz-executor0 Not tainted 4.4.131-gaa3863d #41
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
task: ffff8801d9270000 task.stack: ffff8801d98b0000
RIP: 0010:[<ffffffff833a9a64>]  [<ffffffff833a9a64>] hstcp_ssthresh+0x94/0xf0 net/ipv4/tcp_highspeed.c:156
RSP: 0018:ffff8801d98b7860  EFLAGS: 00010203
RAX: 0000000000000002 RBX: 00000000ff0ecaba RCX: 00000000ef8d0e8a
RDX: dffffc0000000000 RSI: ffffffff833a99e1 RDI: 000000077c687454
RBP: ffff8801d98b7870 R08: ffff8801d9270900 R09: 0000000000000001
R10: 0000000000000000 R11: 0000000000000000 R12: ffffffff84a243e0
R13: ffff8800aed31118 R14: 0000000000000000 R15: ffff8800b50bc360
FS:  00007fdc3a5f6700(0000) GS:ffff8801db300000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b2bc25000 CR3: 00000001cf585000 CR4: 00000000001606f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Stack:
 ffffffff832a1e65 ffff8800aed30a80 ffff8801d98b78a0 ffffffff83250005
 ffff8801bc008000 ffff8800aed30a80 0000000000000002 ffff8800aed31120
 ffff8801d98b78b8 ffffffff83250258 ffff8800aed30a80 ffff8801d98b7a00
Call Trace:
 [<ffffffff83250005>] tcp_init_cwnd_reduction net/ipv4/tcp_input.c:2470 [inline]
 [<ffffffff83250005>] tcp_enter_cwr.part.28+0x245/0x420 net/ipv4/tcp_input.c:2524
 [<ffffffff83250258>] tcp_enter_cwr+0x78/0x90 net/ipv4/tcp_input.c:2522
 [<ffffffff83280055>] tcp_transmit_skb+0x2385/0x2bf0 net/ipv4/tcp_output.c:1034
 [<ffffffff83287d69>] tcp_connect+0x1d59/0x2c60 net/ipv4/tcp_output.c:3276
 [<ffffffff83299801>] tcp_v4_connect+0xf31/0x1890 net/ipv4/tcp_ipv4.c:246
 [<ffffffff832f7a09>] __inet_stream_connect+0x2a9/0xc30 net/ipv4/af_inet.c:615
 [<ffffffff832f83e5>] inet_stream_connect+0x55/0xa0 net/ipv4/af_inet.c:676
 [<ffffffff82f1d6b8>] SYSC_connect+0x1b8/0x300 net/socket.c:1557
 [<ffffffff82f1fff4>] SyS_connect+0x24/0x30 net/socket.c:1538
 [<ffffffff838bfe65>] entry_SYSCALL_64_fastpath+0x22/0x9e
Code: 07 83 c2 03 38 ca 7c 04 84 c9 75 62 48 ba 00 00 00 00 00 fc ff df 8b 9b e8 06 00 00 48 8d 3c dd 84 1e f2 83 48 89 f9 48 c1 e9 03 <0f> b6 0c 11 48 89 fa 83 e2 07 83 c2 03 38 ca 7c 04 84 c9 75 21 
RIP  [<ffffffff833a9a64>] hstcp_ssthresh+0x94/0xf0 net/ipv4/tcp_highspeed.c:156
 RSP <ffff8801d98b7860>
---[ end trace 5a96b71cba5087c9 ]---