syzbot

BUG: please report to dccp@vger.kernel.org => prev = 0, last = 0 at net/dccp/ccids/lib/packet_history.c:425/tfrc_rx_hist_sample_rtt()
CPU: 1 PID: 3930 Comm: syzkaller073310 Not tainted 4.15.0-rc8+ #267
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 <IRQ>
 __dump_stack lib/dump_stack.c:17 [inline]
 dump_stack+0x194/0x257 lib/dump_stack.c:53
 tfrc_rx_hist_sample_rtt+0x407/0x4d0 net/dccp/ccids/lib/packet_history.c:422
 ccid3_hc_rx_packet_recv+0x696/0xeb3 net/dccp/ccids/ccid3.c:765
 ccid_hc_rx_packet_recv net/dccp/ccid.h:185 [inline]
 dccp_deliver_input_to_ccids+0xd9/0x250 net/dccp/input.c:180
 dccp_rcv_established+0x88/0xb0 net/dccp/input.c:378
 dccp_v4_do_rcv+0x135/0x160 net/dccp/ipv4.c:653
 sk_backlog_rcv include/net/sock.h:907 [inline]
 __sk_receive_skb+0x33e/0xc20 net/core/sock.c:511
 dccp_v4_rcv+0xf65/0x1c90 net/dccp/ipv4.c:874
 ip_local_deliver_finish+0x2f1/0xc50 net/ipv4/ip_input.c:216
 NF_HOOK include/linux/netfilter.h:250 [inline]
 ip_local_deliver+0x1ce/0x6e0 net/ipv4/ip_input.c:257
 dst_input include/net/dst.h:466 [inline]
 ip_rcv_finish+0x959/0x1e30 net/ipv4/ip_input.c:397
 NF_HOOK include/linux/netfilter.h:250 [inline]
 ip_rcv+0xc5a/0x1840 net/ipv4/ip_input.c:493
 __netif_receive_skb_core+0x1a41/0x3460 net/core/dev.c:4473
 __netif_receive_skb+0x2c/0x1b0 net/core/dev.c:4538
 process_backlog+0x203/0x740 net/core/dev.c:5217
 napi_poll net/core/dev.c:5615 [inline]
 net_rx_action+0x792/0x1910 net/core/dev.c:5681
 __do_softirq+0x2d7/0xb85 kernel/softirq.c:285
 do_softirq_own_stack+0x2a/0x40 arch/x86/entry/entry_64.S:1150
 </IRQ>
 do_softirq.part.19+0x14d/0x190 kernel/softirq.c:329
 do_softirq kernel/softirq.c:177 [inline]
 __local_bh_enable_ip+0x1ee/0x230 kernel/softirq.c:182
 local_bh_enable include/linux/bottom_half.h:32 [inline]
 rcu_read_unlock_bh include/linux/rcupdate.h:727 [inline]
 ip_finish_output2+0x96e/0x1560 net/ipv4/ip_output.c:231
 ip_finish_output+0x864/0xd10 net/ipv4/ip_output.c:317
 NF_HOOK_COND include/linux/netfilter.h:239 [inline]
 ip_output+0x1d2/0x860 net/ipv4/ip_output.c:405
 dst_output include/net/dst.h:460 [inline]
 ip_local_out+0x95/0x160 net/ipv4/ip_output.c:124
 ip_queue_xmit+0x8c6/0x18e0 net/ipv4/ip_output.c:504
 dccp_transmit_skb+0x9ac/0x10f0 net/dccp/output.c:142
 dccp_xmit_packet+0x215/0x740 net/dccp/output.c:281
 dccp_write_xmit+0x17d/0x1d0 net/dccp/output.c:363
 dccp_sendmsg+0x6d0/0xa80 net/dccp/proto.c:808
 inet_sendmsg+0x11f/0x5e0 net/ipv4/af_inet.c:763
 sock_sendmsg_nosec net/socket.c:638 [inline]
 sock_sendmsg+0xca/0x110 net/socket.c:648
 ___sys_sendmsg+0x767/0x8b0 net/socket.c:2028
 __sys_sendmsg+0xe5/0x210 net/socket.c:2062
 SYSC_sendmsg net/socket.c:2073 [inline]
 SyS_sendmsg+0x2d/0x50 net/socket.c:2069
 entry_SYSCALL_64_fastpath+0x29/0xa0
RIP: 0033:0x446469
RSP: 002b:00007f97bc44dda8 EFLAGS: 00000293 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00000000006dbc3c RCX: 0000000000446469
RDX: 0000000000000080 RSI: 00000000206c8000 RDI: 0000000000000005
RBP: 00000000006dbc38 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000293 R12: f8e4cbe49e572d45
R13: 54c1b85d98aba1df R14: a6eaa24dbeb18c29 R15: 000000000000000c
net_ratelimit: 213 callbacks suppressed
dccp_close: ABORT with 24 bytes unread
dccp_close: ABORT with 24 bytes unread
dccp_close: ABORT with 24 bytes unread
dccp_close: ABORT with 24 bytes unread
dccp_close: ABORT with 24 bytes unread
dccp_close: ABORT with 24 bytes unread
dccp_close: ABORT with 24 bytes unread
dccp_close: ABORT with 24 bytes unread
dccp_close: ABORT with 24 bytes unread
dccp_close: ABORT with 24 bytes unread
net_ratelimit: 236 callbacks suppressed
dccp_close: ABORT with 24 bytes unread
dccp_close: ABORT with 24 bytes unread
dccp_close: ABORT with 24 bytes unread
dccp_close: ABORT with 24 bytes unread
dccp_close: ABORT with 24 bytes unread
dccp_close: ABORT with 24 bytes unread
dccp_close: ABORT with 24 bytes unread
dccp_close: ABORT with 24 bytes unread
dccp_close: ABORT with 24 bytes unread
dccp_close: ABORT with 24 bytes unread