------------[ cut here ]------------
WARNING: CPU: 1 PID: 17656 at net/ipv4/tcp_input.c:2573 tcp_cwnd_reduction+0x329/0x390 net/ipv4/tcp_input.c:2573
Modules linked in:
CPU: 1 PID: 17656 Comm: syz-executor.5 Not tainted 5.12.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:tcp_cwnd_reduction+0x329/0x390 net/ipv4/tcp_input.c:2573
Code: 38 09 00 00 48 83 c4 18 5b 5d 41 5c 41 5d 41 5e 41 5f e9 9a f6 ef f9 e8 95 f6 ef f9 44 39 e5 41 0f 4f ec eb 81 e8 87 f6 ef f9 <0f> 0b eb d6 e8 0e d6 33 fa e9 33 fd ff ff e8 04 d6 33 fa e9 1c fe
RSP: 0018:ffffc9001637f590 EFLAGS: 00010246
RAX: 0000000000040000 RBX: ffff88801d2c0000 RCX: ffffc90013df9000
RDX: 0000000000040000 RSI: ffffffff87846789 RDI: 0000000000000003
RBP: ffffc9001637f790 R08: 0000000000000000 R09: 0000000000000000
R10: ffffffff878464db R11: 0000000000000000 R12: 0000000000000007
R13: 0000000000000000 R14: 0000000000000008 R15: ffff88801d2c0000
FS:  00007f7a77b00700(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f60cd1ab718 CR3: 000000008452e000 CR4: 00000000001506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 tcp_cong_control net/ipv4/tcp_input.c:3439 [inline]
 tcp_ack+0x40ac/0x5970 net/ipv4/tcp_input.c:3843
 tcp_rcv_established+0x56b/0x1eb0 net/ipv4/tcp_input.c:5872
 tcp_v6_do_rcv+0x41d/0x12b0 net/ipv6/tcp_ipv6.c:1490
 sk_backlog_rcv include/net/sock.h:1020 [inline]
 __release_sock+0x134/0x3b0 net/core/sock.c:2550
 release_sock+0x54/0x1b0 net/core/sock.c:3074
 sk_stream_wait_memory+0x608/0xed0 net/core/stream.c:145
 tls_sw_sendmsg+0x57b/0x1800 net/tls/tls_sw.c:1087
 inet6_sendmsg+0x99/0xe0 net/ipv6/af_inet6.c:642
 sock_sendmsg_nosec net/socket.c:654 [inline]
 sock_sendmsg+0xcf/0x120 net/socket.c:674
 __sys_sendto+0x21c/0x320 net/socket.c:1977
 __do_sys_sendto net/socket.c:1989 [inline]
 __se_sys_sendto net/socket.c:1985 [inline]
 __x64_sys_sendto+0xdd/0x1b0 net/socket.c:1985
 do_syscall_64+0x3a/0xb0 arch/x86/entry/common.c:47
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x4665f9
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:00007f7a77b00188 EFLAGS: 00000246 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 000000000056bf60 RCX: 00000000004665f9
RDX: 00000000e0ffffff RSI: 00000000200005c0 RDI: 0000000000000003
RBP: 00000000004bfce1 R08: 0000000000000000 R09: 00000000000000d8
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056bf60
R13: 0000000000a9fb1f R14: 00007f7a77b00300 R15: 0000000000022000