BUG: please report to dccp@vger.kernel.org => prev = 0, last = 0 at net/dccp/ccids/lib/packet_history.c:414/tfrc_rx_hist_sample_rtt() CPU: 0 PID: 32580 Comm: syz-executor.0 Not tainted 5.11.0-rc7-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:79 [inline] dump_stack+0x107/0x163 lib/dump_stack.c:120 tfrc_rx_hist_sample_rtt+0x4a5/0x4b0 net/dccp/ccids/lib/packet_history.c:414 ccid3_hc_rx_packet_recv+0x5b8/0xe90 net/dccp/ccids/ccid3.c:760 ccid_hc_rx_packet_recv net/dccp/ccid.h:182 [inline] dccp_deliver_input_to_ccids+0xe1/0x260 net/dccp/input.c:176 dccp_rcv_established net/dccp/input.c:374 [inline] dccp_rcv_established+0x107/0x160 net/dccp/input.c:364 dccp_v4_do_rcv+0x130/0x190 net/dccp/ipv4.c:657 sk_backlog_rcv include/net/sock.h:1016 [inline] __sk_receive_skb+0x29d/0x830 net/core/sock.c:509 dccp_v4_rcv+0xe8b/0x1850 net/dccp/ipv4.c:880 ip_protocol_deliver_rcu+0x5c/0x8a0 net/ipv4/ip_input.c:204 ip_local_deliver_finish+0x20a/0x370 net/ipv4/ip_input.c:231 NF_HOOK include/linux/netfilter.h:301 [inline] NF_HOOK include/linux/netfilter.h:295 [inline] ip_local_deliver+0x1b3/0x200 net/ipv4/ip_input.c:252 dst_input include/net/dst.h:458 [inline] ip_rcv_finish+0x1da/0x2f0 net/ipv4/ip_input.c:429 NF_HOOK include/linux/netfilter.h:301 [inline] NF_HOOK include/linux/netfilter.h:295 [inline] ip_rcv+0xaa/0xd0 net/ipv4/ip_input.c:540 __netif_receive_skb_one_core+0x114/0x180 net/core/dev.c:5371 __netif_receive_skb+0x27/0x1c0 net/core/dev.c:5485 process_backlog+0x232/0x6c0 net/core/dev.c:6359 __napi_poll+0xaf/0x440 net/core/dev.c:6905 napi_poll net/core/dev.c:6972 [inline] net_rx_action+0x806/0xb40 net/core/dev.c:7050 __do_softirq+0x29b/0x9f6 kernel/softirq.c:343 asm_call_irq_on_stack+0xf/0x20 __run_on_irqstack arch/x86/include/asm/irq_stack.h:26 [inline] run_on_irqstack_cond arch/x86/include/asm/irq_stack.h:77 [inline] do_softirq_own_stack+0xaa/0xd0 arch/x86/kernel/irq_64.c:77 do_softirq kernel/softirq.c:246 [inline] do_softirq+0xb5/0xe0 kernel/softirq.c:233 __local_bh_enable_ip+0xf4/0x110 kernel/softirq.c:196 local_bh_enable include/linux/bottom_half.h:32 [inline] rcu_read_unlock_bh include/linux/rcupdate.h:737 [inline] ip_finish_output2+0x88b/0x21b0 net/ipv4/ip_output.c:231 __ip_finish_output net/ipv4/ip_output.c:308 [inline] __ip_finish_output+0x396/0x640 net/ipv4/ip_output.c:290 ip_finish_output+0x35/0x200 net/ipv4/ip_output.c:318 NF_HOOK_COND include/linux/netfilter.h:290 [inline] ip_output+0x196/0x310 net/ipv4/ip_output.c:432 dst_output include/net/dst.h:448 [inline] ip_local_out net/ipv4/ip_output.c:126 [inline] __ip_queue_xmit+0x8e9/0x1a00 net/ipv4/ip_output.c:533 dccp_transmit_skb+0x973/0x12c0 net/dccp/output.c:138 dccp_xmit_packet+0x270/0x750 net/dccp/output.c:281 dccp_write_xmit+0x16d/0x1d0 net/dccp/output.c:366 dccp_sendmsg+0x920/0xc90 net/dccp/proto.c:794 inet_sendmsg+0x99/0xe0 net/ipv4/af_inet.c:817 sock_sendmsg_nosec net/socket.c:652 [inline] sock_sendmsg+0xcf/0x120 net/socket.c:672 ____sys_sendmsg+0x331/0x810 net/socket.c:2345 ___sys_sendmsg+0xf3/0x170 net/socket.c:2399 __sys_sendmmsg+0x195/0x470 net/socket.c:2489 __do_sys_sendmmsg net/socket.c:2518 [inline] __se_sys_sendmmsg net/socket.c:2515 [inline] __x64_sys_sendmmsg+0x99/0x100 net/socket.c:2515 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x465b09 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 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 bc ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007efddf34a188 EFLAGS: 00000246 ORIG_RAX: 0000000000000133 RAX: ffffffffffffffda RBX: 000000000056c008 RCX: 0000000000465b09 RDX: 0000000004000017 RSI: 0000000020001e80 RDI: 0000000000000004 RBP: 00000000004b069f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056c008 R13: 00007fffe39788df R14: 00007efddf34a300 R15: 0000000000022000 BUG: please report to dccp@vger.kernel.org => prev = 0, last = 0 at net/dccp/ccids/lib/packet_history.c:414/tfrc_rx_hist_sample_rtt() CPU: 0 PID: 32653 Comm: syz-executor.5 Not tainted 5.11.0-rc7-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:79 [inline] dump_stack+0x107/0x163 lib/dump_stack.c:120 tfrc_rx_hist_sample_rtt+0x4a5/0x4b0 net/dccp/ccids/lib/packet_history.c:414 ccid3_hc_rx_packet_recv+0x5b8/0xe90 net/dccp/ccids/ccid3.c:760 ccid_hc_rx_packet_recv net/dccp/ccid.h:182 [inline] dccp_deliver_input_to_ccids+0xe1/0x260 net/dccp/input.c:176 dccp_rcv_established net/dccp/input.c:374 [inline] dccp_rcv_established+0x107/0x160 net/dccp/input.c:364 dccp_v4_do_rcv+0x130/0x190 net/dccp/ipv4.c:657 sk_backlog_rcv include/net/sock.h:1016 [inline] __sk_receive_skb+0x29d/0x830 net/core/sock.c:509 dccp_v4_rcv+0xe8b/0x1850 net/dccp/ipv4.c:880 ip_protocol_deliver_rcu+0x5c/0x8a0 net/ipv4/ip_input.c:204 ip_local_deliver_finish+0x20a/0x370 net/ipv4/ip_input.c:231 NF_HOOK include/linux/netfilter.h:301 [inline] NF_HOOK include/linux/netfilter.h:295 [inline] ip_local_deliver+0x1b3/0x200 net/ipv4/ip_input.c:252 dst_input include/net/dst.h:458 [inline] ip_rcv_finish+0x1da/0x2f0 net/ipv4/ip_input.c:429 NF_HOOK include/linux/netfilter.h:301 [inline] NF_HOOK include/linux/netfilter.h:295 [inline] ip_rcv+0xaa/0xd0 net/ipv4/ip_input.c:540 __netif_receive_skb_one_core+0x114/0x180 net/core/dev.c:5371 __netif_receive_skb+0x27/0x1c0 net/core/dev.c:5485 process_backlog+0x232/0x6c0 net/core/dev.c:6359 __napi_poll+0xaf/0x440 net/core/dev.c:6905 napi_poll net/core/dev.c:6972 [inline] net_rx_action+0x806/0xb40 net/core/dev.c:7050 __do_softirq+0x29b/0x9f6 kernel/softirq.c:343 asm_call_irq_on_stack+0xf/0x20 __run_on_irqstack arch/x86/include/asm/irq_stack.h:26 [inline] run_on_irqstack_cond arch/x86/include/asm/irq_stack.h:77 [inline] do_softirq_own_stack+0xaa/0xd0 arch/x86/kernel/irq_64.c:77 do_softirq kernel/softirq.c:246 [inline] do_softirq+0xb5/0xe0 kernel/softirq.c:233 __local_bh_enable_ip+0xf4/0x110 kernel/softirq.c:196 local_bh_enable include/linux/bottom_half.h:32 [inline] rcu_read_unlock_bh include/linux/rcupdate.h:737 [inline] ip_finish_output2+0x88b/0x21b0 net/ipv4/ip_output.c:231 __ip_finish_output net/ipv4/ip_output.c:308 [inline] __ip_finish_output+0x396/0x640 net/ipv4/ip_output.c:290 ip_finish_output+0x35/0x200 net/ipv4/ip_output.c:318 NF_HOOK_COND include/linux/netfilter.h:290 [inline] ip_output+0x196/0x310 net/ipv4/ip_output.c:432 dst_output include/net/dst.h:448 [inline] ip_local_out net/ipv4/ip_output.c:126 [inline] __ip_queue_xmit+0x8e9/0x1a00 net/ipv4/ip_output.c:533 dccp_transmit_skb+0x973/0x12c0 net/dccp/output.c:138 dccp_xmit_packet+0x270/0x750 net/dccp/output.c:281 dccp_write_xmit+0x16d/0x1d0 net/dccp/output.c:366 dccp_sendmsg+0x920/0xc90 net/dccp/proto.c:794 inet_sendmsg+0x99/0xe0 net/ipv4/af_inet.c:817 sock_sendmsg_nosec net/socket.c:652 [inline] sock_sendmsg+0xcf/0x120 net/socket.c:672 ____sys_sendmsg+0x331/0x810 net/socket.c:2345 ___sys_sendmsg+0xf3/0x170 net/socket.c:2399 __sys_sendmmsg+0x195/0x470 net/socket.c:2489 __do_sys_sendmmsg net/socket.c:2518 [inline] __se_sys_sendmmsg net/socket.c:2515 [inline] __x64_sys_sendmmsg+0x99/0x100 net/socket.c:2515 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x465b09 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 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 bc ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fa236890188 EFLAGS: 00000246 ORIG_RAX: 0000000000000133 RAX: ffffffffffffffda RBX: 000000000056c008 RCX: 0000000000465b09 RDX: 0000000004000017 RSI: 0000000020001e80 RDI: 0000000000000004 RBP: 00000000004b069f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056c008 R13: 00007fffe9adcd7f R14: 00007fa236890300 R15: 0000000000022000