audit: type=1326 audit(1525672928.830:16): auid=4294967295 uid=0 gid=0 ses=4294967295 subj=kernel pid=20602 comm="syz-executor7" exe="/root/syz-executor7" sig=31 arch=c000003e syscall=202 compat=0 ip=0x455979 code=0x0 audit: type=1326 audit(1525672928.860:17): auid=4294967295 uid=0 gid=0 ses=4294967295 subj=kernel pid=20602 comm="syz-executor7" exe="/root/syz-executor7" sig=31 arch=c000003e syscall=202 compat=0 ip=0x455979 code=0x0 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: 0 PID: 20568 Comm: syz-executor4 Not tainted 4.4.131-g6ec0e3f #35 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 task: ffff8800b04f4800 task.stack: ffff8800b0098000 RIP: 0010:[] [] hstcp_ssthresh+0x94/0xf0 net/ipv4/tcp_highspeed.c:156 RSP: 0018:ffff8800b009f860 EFLAGS: 00010207 RAX: 0000000000000002 RBX: 00000000ddadb214 RCX: 00000000ce2bf5d4 RDX: dffffc0000000000 RSI: ffffffff833a9871 RDI: 00000006715faea4 RBP: ffff8800b009f870 R08: ffff8800b04f5100 R09: 0000000000000001 R10: 0000000000000000 R11: 0000000000000000 R12: ffffffff84a243a0 R13: ffff8800b0d41b98 R14: 0000000000000000 R15: ffff8800b3c394e0 FS: 00007f2b690f4700(0000) GS:ffff8801db200000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b2bc22000 CR3: 00000001ccac8000 CR4: 00000000001606f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Stack: ffffffff832a1cf5 ffff8800b0d41500 ffff8800b009f8a0 ffffffff8324fe95 ffff8800a5213b80 ffff8800b0d41500 0000000000000002 ffff8800b0d41ba0 ffff8800b009f8b8 ffffffff832500e8 ffff8800b0d41500 ffff8800b009fa00 Call Trace: [] tcp_init_cwnd_reduction net/ipv4/tcp_input.c:2470 [inline] [] tcp_enter_cwr.part.28+0x245/0x420 net/ipv4/tcp_input.c:2524 [] tcp_enter_cwr+0x78/0x90 net/ipv4/tcp_input.c:2522 [] tcp_transmit_skb+0x2385/0x2bf0 net/ipv4/tcp_output.c:1034 [] tcp_connect+0x1d59/0x2c60 net/ipv4/tcp_output.c:3276 [] tcp_v4_connect+0xf31/0x1890 net/ipv4/tcp_ipv4.c:246 [] __inet_stream_connect+0x2a9/0xc30 net/ipv4/af_inet.c:615 [] inet_stream_connect+0x55/0xa0 net/ipv4/af_inet.c:676 [] SYSC_connect+0x1b8/0x300 net/socket.c:1557 [] SyS_connect+0x24/0x30 net/socket.c:1538 [] 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 04 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 [] hstcp_ssthresh+0x94/0xf0 net/ipv4/tcp_highspeed.c:156 RSP ---[ end trace e07fbf1f9f432a18 ]---