------------[ cut here ]------------
WARNING: CPU: 1 PID: 19 at net/ipv4/tcp_input.c:2613 tcp_cwnd_reduction+0x321/0x380 net/ipv4/tcp_input.c:2613
Modules linked in:
CPU: 1 PID: 19 Comm: ksoftirqd/1 Not tainted 5.16.0-rc2-next-20211125-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: 78 09 00 00 48 83 c4 18 5b 5d 41 5c 41 5d 41 5e 41 5f e9 a2 46 be f9 e8 9d 46 be f9 41 39 ec 41 0f 4e ec eb 89 e8 8f 46 be f9 <0f> 0b eb d6 e8 76 d5 08 fa e9 38 fd ff ff e8 6c d5 08 fa e9 20 fe
RSP: 0018:ffffc90000d97578 EFLAGS: 00010246
RAX: 0000000000000000 RBX: ffff88814b42b200 RCX: 0000000000000100
RDX: ffff8880119457c0 RSI: ffffffff87b99e51 RDI: 0000000000000003
RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000000
R10: ffffffff87b99ba8 R11: 0000000000000000 R12: 0000000000000001
R13: 0000000000000000 R14: 0000000000000004 R15: ffff88814b42b200
FS:  0000000000000000(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000021000000 CR3: 0000000060be8000 CR4: 00000000003526e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 00000000b8fecd19 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 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:1522
 tcp_v6_rcv+0x23be/0x2d10 net/ipv6/tcp_ipv6.c:1766
 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+0x27f/0x3b0 net/ipv6/ip6_input.c:297
 __netif_receive_skb_one_core+0x114/0x180 net/core/dev.c:5343
 __netif_receive_skb+0x24/0x1b0 net/core/dev.c:5457
 process_backlog+0x2a5/0x6c0 net/core/dev.c:5789
 __napi_poll+0xaf/0x440 net/core/dev.c:6357
 napi_poll net/core/dev.c:6424 [inline]
 net_rx_action+0x801/0xb40 net/core/dev.c:6511
 __do_softirq+0x29b/0x9c2 kernel/softirq.c:558
 run_ksoftirqd kernel/softirq.c:921 [inline]
 run_ksoftirqd+0x2d/0x60 kernel/softirq.c:913
 smpboot_thread_fn+0x645/0x9c0 kernel/smpboot.c:164
 kthread+0x405/0x4f0 kernel/kthread.c:345
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
 </TASK>