BUG: please report to dccp@vger.kernel.org => prev = 0, last = 0 at net/dccp/ccids/lib/packet_history.c:422/tfrc_rx_hist_sample_rtt() CPU: 1 PID: 28030 Comm: syz-executor.4 Not tainted 5.1.0+ #5 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x172/0x1f0 lib/dump_stack.c:113 tfrc_rx_hist_sample_rtt.cold+0x56/0x61 net/dccp/ccids/lib/packet_history.c:422 ccid3_hc_rx_packet_recv+0x5c6/0xeb0 net/dccp/ccids/ccid3.c:767 ccid_hc_rx_packet_recv net/dccp/ccid.h:185 [inline] dccp_deliver_input_to_ccids+0xee/0x280 net/dccp/input.c:180 dccp_rcv_established net/dccp/input.c:378 [inline] dccp_rcv_established+0x83/0xb0 net/dccp/input.c:368 dccp_v4_do_rcv+0x139/0x190 net/dccp/ipv4.c:659 sk_backlog_rcv include/net/sock.h:950 [inline] __sk_receive_skb+0x33a/0xbe0 net/core/sock.c:528 dccp_v4_rcv+0xeaa/0x1bf1 net/dccp/ipv4.c:880 ip_protocol_deliver_rcu+0x74c/0x940 net/ipv4/ip_input.c:211 ip_local_deliver_finish+0x23b/0x390 net/ipv4/ip_input.c:238 NF_HOOK include/linux/netfilter.h:305 [inline] NF_HOOK include/linux/netfilter.h:299 [inline] ip_local_deliver+0x1e9/0x520 net/ipv4/ip_input.c:259 dst_input include/net/dst.h:439 [inline] ip_rcv_finish+0x1e1/0x300 net/ipv4/ip_input.c:420 NF_HOOK include/linux/netfilter.h:305 [inline] NF_HOOK include/linux/netfilter.h:299 [inline] ip_rcv+0xe8/0x3f0 net/ipv4/ip_input.c:530 __netif_receive_skb_one_core+0x18d/0x1f0 net/core/dev.c:4990 __netif_receive_skb+0x2c/0x1d0 net/core/dev.c:5104 process_backlog+0x206/0x750 net/core/dev.c:5944 napi_poll net/core/dev.c:6367 [inline] net_rx_action+0x4fa/0x1070 net/core/dev.c:6433 __do_softirq+0x266/0x95a kernel/softirq.c:293 do_softirq_own_stack+0x2a/0x40 arch/x86/entry/entry_64.S:1026 do_softirq.part.0+0x11a/0x170 kernel/softirq.c:338 do_softirq kernel/softirq.c:330 [inline] __local_bh_enable_ip+0x211/0x270 kernel/softirq.c:190 local_bh_enable include/linux/bottom_half.h:32 [inline] rcu_read_unlock_bh include/linux/rcupdate.h:684 [inline] ip_finish_output2+0x952/0x24e0 net/ipv4/ip_output.c:228 ip_finish_output+0x734/0xd50 net/ipv4/ip_output.c:314 NF_HOOK_COND include/linux/netfilter.h:294 [inline] ip_output+0x21f/0x670 net/ipv4/ip_output.c:402 dst_output include/net/dst.h:433 [inline] ip_local_out+0xc4/0x1b0 net/ipv4/ip_output.c:124 __ip_queue_xmit+0x86f/0x1bf0 net/ipv4/ip_output.c:502 ip_queue_xmit+0x5a/0x70 include/net/ip.h:202 dccp_transmit_skb+0xca5/0x12c0 net/dccp/output.c:142 dccp_xmit_packet+0x1f6/0x660 net/dccp/output.c:281 dccp_write_xmit+0x181/0x1e0 net/dccp/output.c:363 dccp_sendmsg+0xa60/0xd00 net/dccp/proto.c:816 inet_sendmsg+0x147/0x5e0 net/ipv4/af_inet.c:802 sock_sendmsg_nosec net/socket.c:660 [inline] sock_sendmsg+0xf2/0x170 net/socket.c:671 __sys_sendto+0x262/0x380 net/socket.c:1964 __do_sys_sendto net/socket.c:1976 [inline] __se_sys_sendto net/socket.c:1972 [inline] __x64_sys_sendto+0xe1/0x1a0 net/socket.c:1972 do_syscall_64+0x103/0x670 arch/x86/entry/common.c:298 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x458da9 Code: ad b8 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 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 0f 83 7b b8 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f756cdcfc78 EFLAGS: 00000246 ORIG_RAX: 000000000000002c RAX: ffffffffffffffda RBX: 0000000000000006 RCX: 0000000000458da9 RDX: 00000000000000c5 RSI: 0000000020000300 RDI: 0000000000000004 RBP: 000000000073c040 R08: 0000000000000000 R09: 0000000000000000 R10: 000000000400c000 R11: 0000000000000246 R12: 00007f756cdd06d4 R13: 00000000004c682f R14: 00000000004db468 R15: 00000000ffffffff protocol 88fb is buggy, dev hsr_slave_0 protocol 88fb is buggy, dev hsr_slave_1