------------[ cut here ]------------ WARNING: CPU: 1 PID: 13789 at net/ipv4/tcp_input.c:2573 tcp_cwnd_reduction+0x329/0x390 net/ipv4/tcp_input.c:2573 Modules linked in: CPU: 1 PID: 13789 Comm: syz-executor.1 Not tainted 5.13.0-rc3-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 a6 e5 f9 e8 95 a6 e5 f9 44 39 e5 41 0f 4f ec eb 81 e8 87 a6 e5 f9 <0f> 0b eb d6 e8 ee a7 2a fa e9 33 fd ff ff e8 e4 a7 2a fa e9 1c fe RSP: 0018:ffffc9000395f6d0 EFLAGS: 00010216 RAX: 000000000002185a RBX: ffff88801c36de00 RCX: ffffc9000c3e1000 RDX: 0000000000040000 RSI: ffffffff878f3239 RDI: 0000000000000003 RBP: ffffc9000395f8d0 R08: 0000000000000000 R09: 0000000000000000 R10: ffffffff878f2f8b R11: 0000000000000000 R12: 0000000000000002 R13: 0000000000000000 R14: 0000000000000004 R15: ffff88801c36de00 FS: 00007f8511647700(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000970004 CR3: 000000002af5f000 CR4: 00000000001506f0 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+0x40b4/0x5970 net/ipv4/tcp_input.c:3843 tcp_rcv_established+0x56b/0x1eb0 net/ipv4/tcp_input.c:5872 tcp_v4_do_rcv+0x5d1/0x870 net/ipv4/tcp_ipv4.c:1694 sk_backlog_rcv include/net/sock.h:1020 [inline] __release_sock+0x134/0x3b0 net/core/sock.c:2550 __sk_flush_backlog+0x22/0x30 net/core/sock.c:2570 sk_flush_backlog include/net/sock.h:1107 [inline] tcp_sendmsg_locked+0x27e6/0x2e40 net/ipv4/tcp.c:1305 tcp_sendmsg+0x2b/0x40 net/ipv4/tcp.c:1458 inet_sendmsg+0x99/0xe0 net/ipv4/af_inet.c:821 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: 0033:0x4665d9 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:00007f8511647188 EFLAGS: 00000246 ORIG_RAX: 000000000000002c RAX: ffffffffffffffda RBX: 000000000056bf80 RCX: 00000000004665d9 RDX: 00000000fffffd46 RSI: 0000000020000240 RDI: 0000000000000003 RBP: 00000000004bfcb9 R08: 0000000000000000 R09: 00000000000001f4 R10: 00000000000081f4 R11: 0000000000000246 R12: 000000000056bf80 R13: 0000000000a9fb1f R14: 00007f8511647300 R15: 0000000000022000