syzbot

net_ratelimit: 5 callbacks suppressed
ccid3_first_li: No RTT estimate available, using fallback RTT
ccid3_first_li: X_recv==0
BUG: stored value of X_recv is zero at net/dccp/ccids/ccid3.c:691/ccid3_first_li()
CPU: 1 PID: 12461 Comm: syz-executor.1 Not tainted 6.7.0-syzkaller-04629-g3e7aeb78ab01 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/17/2023
Call Trace:
 <IRQ>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1e7/0x2d0 lib/dump_stack.c:106
 ccid3_first_li+0x34a/0x410 net/dccp/ccids/ccid3.c:691
 tfrc_lh_interval_add+0x598/0x7c0 net/dccp/ccids/lib/loss_interval.c:157
 tfrc_rx_handle_loss+0x759/0x1870 net/dccp/ccids/lib/packet_history.c:328
 ccid3_hc_rx_packet_recv+0x347/0xe60 net/dccp/ccids/ccid3.c:744
 ccid_hc_rx_packet_recv net/dccp/ccid.h:182 [inline]
 dccp_deliver_input_to_ccids net/dccp/input.c:176 [inline]
 dccp_rcv_established+0x1b7/0x310 net/dccp/input.c:374
 dccp_v4_do_rcv+0xff/0x1f0 net/dccp/ipv4.c:675
 sk_backlog_rcv include/net/sock.h:1092 [inline]
 __sk_receive_skb+0x41e/0x9d0 net/core/sock.c:567
 ip_protocol_deliver_rcu+0x208/0x3f0 net/ipv4/ip_input.c:205
 ip_local_deliver_finish+0x2b6/0x500 net/ipv4/ip_input.c:233
 NF_HOOK+0x3a1/0x450 include/linux/netfilter.h:314
 NF_HOOK+0x3a1/0x450 include/linux/netfilter.h:314
 __netif_receive_skb_one_core net/core/dev.c:5534 [inline]
 __netif_receive_skb+0x1ca/0x530 net/core/dev.c:5648
 process_backlog+0x385/0x760 net/core/dev.c:5976
 __napi_poll+0xc7/0x480 net/core/dev.c:6576
 napi_poll net/core/dev.c:6645 [inline]
 net_rx_action+0x78b/0x1010 net/core/dev.c:6778
 __do_softirq+0x2b8/0x939 kernel/softirq.c:553
 do_softirq+0x11b/0x1e0 kernel/softirq.c:454
 </IRQ>
 <TASK>
 __local_bh_enable_ip+0x1b7/0x1f0 kernel/softirq.c:381
 dccp_sendmsg+0x4de/0xb70 net/dccp/proto.c:803
 sock_sendmsg_nosec net/socket.c:730 [inline]
 __sock_sendmsg net/socket.c:745 [inline]
 ____sys_sendmsg+0x592/0x890 net/socket.c:2584
 ___sys_sendmsg net/socket.c:2638 [inline]
 __sys_sendmmsg+0x3b2/0x730 net/socket.c:2724
 __do_sys_sendmmsg net/socket.c:2753 [inline]
 __se_sys_sendmmsg net/socket.c:2750 [inline]
 __x64_sys_sendmmsg+0xa0/0xb0 net/socket.c:2750
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf5/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x63/0x6b
RIP: 0033:0x7f60a4c7cd29
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 00 00 90 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 b0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f60a5a120c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000133
RAX: ffffffffffffffda RBX: 00007f60a4dabf80 RCX: 00007f60a4c7cd29
RDX: 0000000000000002 RSI: 0000000020005180 RDI: 0000000000000004
RBP: 00007f60a4cc947a R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 000000000000000b R14: 00007f60a4dabf80 R15: 00007ffc16a36b88
 </TASK>
vkms_vblank_simulate: vblank timer overrun
vkms_vblank_simulate: vblank timer overrun