------------[ cut here ]------------ WARNING: CPU: 1 PID: 32625 at net/ipv4/tcp_input.c:2613 tcp_cwnd_reduction+0x321/0x380 net/ipv4/tcp_input.c:2613 Modules linked in: CPU: 1 PID: 32625 Comm: syz-executor.1 Not tainted 5.15.0-rc6-next-20211025-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 12 66 bc f9 e8 0d 66 bc f9 41 39 ec 41 0f 4e ec eb 89 e8 ff 65 bc f9 <0f> 0b eb d6 e8 36 14 03 fa e9 38 fd ff ff e8 2c 14 03 fa e9 20 fe RSP: 0018:ffffc90004e2f6d0 EFLAGS: 00010216 RAX: 000000000001b1ab RBX: ffff8880734b9800 RCX: ffffc9000617a000 RDX: 0000000000040000 RSI: ffffffff87bb3ac1 RDI: 0000000000000003 RBP: 0000000000000002 R08: 0000000000000000 R09: 0000000000000000 R10: ffffffff87bb3818 R11: 0000000000000000 R12: 0000000000000002 R13: 0000000000000000 R14: 0000000000000004 R15: ffff8880734b9800 FS: 00007fee3713c700(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b2e724000 CR3: 000000004650b000 CR4: 00000000003506e0 Call Trace: tcp_cong_control net/ipv4/tcp_input.c:3485 [inline] tcp_ack+0x3fc1/0x5720 net/ipv4/tcp_input.c:3889 tcp_rcv_established+0x5d7/0x2130 net/ipv4/tcp_input.c:5936 tcp_v4_do_rcv+0x5d4/0x880 net/ipv4/tcp_ipv4.c:1713 sk_backlog_rcv include/net/sock.h:1025 [inline] __release_sock+0x134/0x3b0 net/core/sock.c:2768 __sk_flush_backlog+0x22/0x30 net/core/sock.c:2788 sk_flush_backlog include/net/sock.h:1112 [inline] tcp_sendmsg_locked+0x2864/0x2f90 net/ipv4/tcp.c:1287 tcp_sendmsg+0x2b/0x40 net/ipv4/tcp.c:1443 inet_sendmsg+0x99/0xe0 net/ipv4/af_inet.c:817 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: 0033:0x7fee39bc6a39 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:00007fee3713c188 EFLAGS: 00000246 ORIG_RAX: 000000000000002c RAX: ffffffffffffffda RBX: 00007fee39cc9f60 RCX: 00007fee39bc6a39 RDX: 00000000fffffd46 RSI: 0000000020000240 RDI: 0000000000000003 RBP: 00007fee39c20e8f R08: 0000000000000000 R09: 00000000000001f4 R10: 00000000000081f4 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffcb302ea1f R14: 00007fee3713c300 R15: 0000000000022000