BUG: please report to dccp@vger.kernel.org => prev = 0, last = 0 at net/dccp/ccids/lib/packet_history.c:417/tfrc_rx_hist_sample_rtt() CPU: 0 PID: 5886 Comm: syz-executor.0 Not tainted 6.4.0-rc1-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/14/2023 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e7/0x2d0 lib/dump_stack.c:106 tfrc_rx_hist_sample_rtt+0x374/0x460 net/dccp/ccids/lib/packet_history.c:414 ccid3_hc_rx_packet_recv+0x632/0xd30 net/dccp/ccids/ccid3.c:760 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+0xd1/0x1a0 net/dccp/ipv4.c:676 sk_backlog_rcv include/net/sock.h:1113 [inline] __sk_receive_skb+0x41e/0x9d0 net/core/sock.c:565 ip_protocol_deliver_rcu+0x5a3/0xd20 net/ipv4/ip_input.c:205 ip_local_deliver_finish+0x282/0x460 net/ipv4/ip_input.c:233 NF_HOOK+0x368/0x410 include/linux/netfilter.h:303 NF_HOOK+0x368/0x410 include/linux/netfilter.h:303 __netif_receive_skb_one_core net/core/dev.c:5491 [inline] __netif_receive_skb+0x1ca/0x530 net/core/dev.c:5605 process_backlog+0x34b/0x710 net/core/dev.c:5933 __napi_poll+0xc7/0x470 net/core/dev.c:6496 napi_poll net/core/dev.c:6563 [inline] net_rx_action+0x78b/0x1010 net/core/dev.c:6696 __do_softirq+0x2ab/0x908 kernel/softirq.c:571 do_softirq+0x166/0x250 kernel/softirq.c:472 __local_bh_enable_ip+0x1b5/0x1f0 kernel/softirq.c:396 rcu_read_unlock_bh include/linux/rcupdate.h:843 [inline] __dev_queue_xmit+0x1530/0x3750 net/core/dev.c:4271 dev_queue_xmit include/linux/netdevice.h:3085 [inline] neigh_hh_output include/net/neighbour.h:528 [inline] neigh_output include/net/neighbour.h:542 [inline] ip_finish_output2+0xcab/0x1250 net/ipv4/ip_output.c:229 dst_output include/net/dst.h:458 [inline] ip_local_out net/ipv4/ip_output.c:126 [inline] __ip_queue_xmit+0x12dc/0x1d80 net/ipv4/ip_output.c:533 dccp_transmit_skb+0xc85/0x10b0 net/dccp/output.c:138 dccp_xmit_packet+0x2ef/0x530 net/dccp/output.c:281 dccp_write_xmit+0x135/0x220 net/dccp/output.c:366 dccp_sendmsg+0x666/0x9e0 net/dccp/proto.c:788 sock_sendmsg_nosec net/socket.c:724 [inline] sock_sendmsg net/socket.c:747 [inline] ____sys_sendmsg+0x58f/0x890 net/socket.c:2503 ___sys_sendmsg net/socket.c:2557 [inline] __sys_sendmsg+0x2ad/0x390 net/socket.c:2586 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x41/0x90 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7f952608c0f9 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 f1 19 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 b8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f95253fe168 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007f95261abf80 RCX: 00007f952608c0f9 RDX: 000000000c004004 RSI: 0000000020004340 RDI: 0000000000000005 RBP: 00007f95260e7b39 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffe0f7b980f R14: 00007f95253fe300 R15: 0000000000022000