------------[ cut here ]------------ WARNING: CPU: 0 PID: 8925 at net/ipv4/tcp_input.c:2613 tcp_cwnd_reduction+0x329/0x390 net/ipv4/tcp_input.c:2613 Modules linked in: CPU: 0 PID: 8925 Comm: syz-executor.5 Not tainted 5.16.0-rc8-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:2613 Code: 80 09 00 00 48 83 c4 18 5b 5d 41 5c 41 5d 41 5e 41 5f e9 9a b2 c6 f9 e8 95 b2 c6 f9 44 39 e5 41 0f 4f ec eb 81 e8 87 b2 c6 f9 <0f> 0b eb d6 e8 8e 71 0d fa e9 33 fd ff ff e8 84 71 0d fa e9 1c fe RSP: 0018:ffffc90011adf6b8 EFLAGS: 00010216 RAX: 000000000001bf9b RBX: ffff88805a3cbfc0 RCX: ffffc90002d01000 RDX: 0000000000040000 RSI: ffffffff87b0dfa9 RDI: 0000000000000003 RBP: ffffc90011adf8b8 R08: 0000000000000000 R09: 0000000000000000 R10: ffffffff87b0dcfb R11: 0000000000000000 R12: 0000000000000012 R13: 0000000000000000 R14: 0000000000000008 R15: ffff88805a3cbfc0 FS: 0000000000000000(0000) GS:ffff8880b9d00000(0063) knlGS:00000000f58abb40 CS: 0010 DS: 002b ES: 002b CR0: 0000000080050033 CR2: 00000000f70215dc CR3: 0000000078c68000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: tcp_cong_control net/ipv4/tcp_input.c:3485 [inline] tcp_ack+0x40f4/0x5900 net/ipv4/tcp_input.c:3889 tcp_rcv_established+0x5d9/0x2130 net/ipv4/tcp_input.c:5936 tcp_v4_do_rcv+0x65a/0x970 net/ipv4/tcp_ipv4.c:1719 sk_backlog_rcv include/net/sock.h:1030 [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:1117 [inline] tcp_sendmsg_locked+0x2989/0x3040 net/ipv4/tcp.c:1277 tcp_sendmsg+0x2b/0x40 net/ipv4/tcp.c:1440 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] __ia32_sys_sendto+0xdb/0x1b0 net/socket.c:2044 do_syscall_32_irqs_on arch/x86/entry/common.c:112 [inline] __do_fast_syscall_32+0x65/0xf0 arch/x86/entry/common.c:178 do_fast_syscall_32+0x2f/0x70 arch/x86/entry/common.c:203 entry_SYSENTER_compat_after_hwframe+0x4d/0x5c RIP: 0023:0xf6eb1549 Code: 03 74 c0 01 10 05 03 74 b8 01 10 06 03 74 b4 01 10 07 03 74 b0 01 10 08 03 74 d8 01 00 00 00 00 00 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 8d b4 26 00 00 00 00 8d b4 26 00 00 00 00 RSP: 002b:00000000f58ab5bc EFLAGS: 00000296 ORIG_RAX: 0000000000000171 RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 0000000020f6f000 RDX: 00000000fffffea7 RSI: 0000000020000018 RDI: 0000000020b63fe4 RBP: 000000000000001c R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 ---------------- Code disassembly (best guess): 0: 03 74 c0 01 add 0x1(%rax,%rax,8),%esi 4: 10 05 03 74 b8 01 adc %al,0x1b87403(%rip) # 0x1b8740d a: 10 06 adc %al,(%rsi) c: 03 74 b4 01 add 0x1(%rsp,%rsi,4),%esi 10: 10 07 adc %al,(%rdi) 12: 03 74 b0 01 add 0x1(%rax,%rsi,4),%esi 16: 10 08 adc %cl,(%rax) 18: 03 74 d8 01 add 0x1(%rax,%rbx,8),%esi 1c: 00 00 add %al,(%rax) 1e: 00 00 add %al,(%rax) 20: 00 51 52 add %dl,0x52(%rcx) 23: 55 push %rbp 24: 89 e5 mov %esp,%ebp 26: 0f 34 sysenter 28: cd 80 int $0x80 * 2a: 5d pop %rbp <-- trapping instruction 2b: 5a pop %rdx 2c: 59 pop %rcx 2d: c3 retq 2e: 90 nop 2f: 90 nop 30: 90 nop 31: 90 nop 32: 8d b4 26 00 00 00 00 lea 0x0(%rsi,%riz,1),%esi 39: 8d b4 26 00 00 00 00 lea 0x0(%rsi,%riz,1),%esi