------------[ cut here ]------------
WARNING: CPU: 0 PID: 17085 at net/ipv4/tcp_input.c:2613 tcp_cwnd_reduction+0x321/0x380 net/ipv4/tcp_input.c:2613
Modules linked in:
CPU: 0 PID: 17085 Comm: syz-executor.2 Not tainted 5.16.0-rc5-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:tcp_cwnd_reduction+0x321/0x380 net/ipv4/tcp_input.c:2613
Code: 80 09 00 00 48 83 c4 18 5b 5d 41 5c 41 5d 41 5e 41 5f e9 02 a6 c6 f9 e8 fd a5 c6 f9 41 39 ec 41 0f 4e ec eb 89 e8 ef a5 c6 f9 <0f> 0b eb d6 e8 26 67 0d fa e9 38 fd ff ff e8 1c 67 0d fa e9 20 fe
RSP: 0018:ffffc900000076b0 EFLAGS: 00010246

RAX: 0000000000000000 RBX: ffff88802131bfc0 RCX: 0000000000000100
RDX: ffff888061b8ba00 RSI: ffffffff87b10571 RDI: 0000000000000003
RBP: 0000000000000012 R08: 0000000000000000 R09: 0000000000000000
R10: ffffffff87b102c8 R11: 0000000000000000 R12: 0000000000000012
R13: 0000000000000000 R14: 0000000000000004 R15: ffff88802131bfc0
FS:  00007fe460cd7700(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000021000000 CR3: 0000000078377000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 tcp_cong_control net/ipv4/tcp_input.c:3485 [inline]
 tcp_ack+0x4160/0x5920 net/ipv4/tcp_input.c:3889
 tcp_rcv_established+0x5d7/0x2130 net/ipv4/tcp_input.c:5936
 tcp_v6_do_rcv+0x461/0x1320 net/ipv6/tcp_ipv6.c:1521
 tcp_v6_rcv+0x236d/0x2cb0 net/ipv6/tcp_ipv6.c:1764
 ip6_protocol_deliver_rcu+0x2e9/0x1ca0 net/ipv6/ip6_input.c:422
 ip6_input_finish+0x62/0x170 net/ipv6/ip6_input.c:463
 NF_HOOK include/linux/netfilter.h:307 [inline]
 NF_HOOK include/linux/netfilter.h:301 [inline]
 ip6_input+0x9c/0xd0 net/ipv6/ip6_input.c:472
 dst_input include/net/dst.h:460 [inline]
 ip6_rcv_finish net/ipv6/ip6_input.c:76 [inline]
 NF_HOOK include/linux/netfilter.h:307 [inline]
 NF_HOOK include/linux/netfilter.h:301 [inline]
 ipv6_rcv+0x28c/0x3c0 net/ipv6/ip6_input.c:297
 __netif_receive_skb_one_core+0x114/0x180 net/core/dev.c:5465
 __netif_receive_skb+0x24/0x1b0 net/core/dev.c:5579
 process_backlog+0x2a5/0x6c0 net/core/dev.c:6455
 __napi_poll+0xaf/0x440 net/core/dev.c:7023
 napi_poll net/core/dev.c:7090 [inline]
 net_rx_action+0x801/0xb40 net/core/dev.c:7177
 __do_softirq+0x29b/0x9c2 kernel/softirq.c:558
 do_softirq.part.0+0xde/0x130 kernel/softirq.c:459
 </IRQ>
 <TASK>
 do_softirq kernel/softirq.c:451 [inline]
 __local_bh_enable_ip+0x102/0x120 kernel/softirq.c:383
 tcp_sendmsg+0x36/0x40 net/ipv4/tcp.c:1441
 inet6_sendmsg+0x99/0xe0 net/ipv6/af_inet6.c:644
 sock_sendmsg_nosec net/socket.c:704 [inline]
 sock_sendmsg+0xcf/0x120 net/socket.c:724
 __sys_sendto+0x21c/0x320 net/socket.c:2036
 __do_sys_sendto net/socket.c:2048 [inline]
 __se_sys_sendto net/socket.c:2044 [inline]
 __x64_sys_sendto+0xdd/0x1b0 net/socket.c:2044
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7fe462361e99
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:00007fe460cd7168 EFLAGS: 00000246 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 00007fe462474f60 RCX: 00007fe462361e99
RDX: fffffffffffffea7 RSI: 0000000020f6f000 RDI: 0000000000000004
RBP: 00007fe4623bbff1 R08: 0000000020b63fe4 R09: 000000000000001c
R10: 0000000020000004 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fe4629a8b1f R14: 00007fe460cd7300 R15: 0000000000022000
 </TASK>