------------[ cut here ]------------
WARNING: CPU: 1 PID: 9675 at net/ipv4/tcp_input.c:2613 tcp_cwnd_reduction net/ipv4/tcp_input.c:2613 [inline]
WARNING: CPU: 1 PID: 9675 at net/ipv4/tcp_input.c:2613 tcp_cong_control net/ipv4/tcp_input.c:3485 [inline]
WARNING: CPU: 1 PID: 9675 at net/ipv4/tcp_input.c:2613 tcp_ack+0x2ce6/0x42e0 net/ipv4/tcp_input.c:3889
Modules linked in:
CPU: 1 PID: 9675 Comm: syz-executor.0 Not tainted 5.16.0-rc6-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:tcp_cwnd_reduction net/ipv4/tcp_input.c:2613 [inline]
RIP: 0010:tcp_cong_control net/ipv4/tcp_input.c:3485 [inline]
RIP: 0010:tcp_ack+0x2ce6/0x42e0 net/ipv4/tcp_input.c:3889
Code: 04 01 84 c0 0f 85 d5 15 00 00 48 8b 84 24 a0 00 00 00 80 60 01 7f 49 bc 00 00 00 00 00 fc ff df e9 f7 dc ff ff e8 ba 9e d4 f8 <0f> 0b 49 bc 00 00 00 00 00 fc ff df e9 f0 f9 ff ff e8 a4 9e d4 f8
RSP: 0018:ffffc90005227520 EFLAGS: 00010283
RAX: ffffffff88afed56 RBX: ffff888077605d94 RCX: 0000000000040000
RDX: ffffc90002f52000 RSI: 00000000000032d4 RDI: 00000000000032d5
RBP: ffffc900052277d0 R08: ffffffff88afe1aa R09: ffffffff88b24c9b
R10: 0000000000000002 R11: ffff8880735ad700 R12: dffffc0000000000
R13: 0000000000000009 R14: 0000000000000000 R15: 0000000000005706
FS:  00007fcfea8a3700(0000) GS:ffff8880b9b00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ff88dc0a000 CR3: 0000000023356000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 tcp_rcv_established+0x7d7/0x22b0 net/ipv4/tcp_input.c:5936
 tcp_v4_do_rcv+0x3eb/0x950 net/ipv4/tcp_ipv4.c:1716
 sk_backlog_rcv include/net/sock.h:1030 [inline]
 __release_sock+0x1d8/0x4c0 net/core/sock.c:2768
 __sk_flush_backlog+0x22/0x30 net/core/sock.c:2788
 sk_flush_backlog include/net/sock.h:1117 [inline]
 tcp_sendmsg_locked+0x33fa/0x48a0 net/ipv4/tcp.c:1277
 tcp_sendmsg+0x2c/0x40 net/ipv4/tcp.c:1440
 sock_sendmsg_nosec net/socket.c:704 [inline]
 sock_sendmsg net/socket.c:724 [inline]
 __sys_sendto+0x42e/0x5b0 net/socket.c:2036
 __do_sys_sendto net/socket.c:2048 [inline]
 __se_sys_sendto net/socket.c:2044 [inline]
 __x64_sys_sendto+0xda/0xf0 net/socket.c:2044
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x44/0xd0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7fcfebf2de99
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 bc ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fcfea8a3168 EFLAGS: 00000246 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 00007fcfec040f60 RCX: 00007fcfebf2de99
RDX: 00000000fffffd46 RSI: 0000000020000240 RDI: 0000000000000003
RBP: 00007fcfebf87ff1 R08: 0000000000000000 R09: 00000000000001f4
R10: 00000000000081f4 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffc6c516fbf R14: 00007fcfea8a3300 R15: 0000000000022000
 </TASK>