On Thu, Dec 20, 2018 at 02:55:03AM -0800, syzbot wrote: > Hello, > > syzbot found the following crash on: > > HEAD commit: 6531e115b7ab Merge branch 'akpm' (patches from Andrew) > git tree: upstream > console output: https://syzkaller.appspot.com/x/log.txt?x=13b0bd5d400000 > kernel config: https://syzkaller.appspot.com/x/.config?x=c8970c89a0efbb23 > dashboard link: https://syzkaller.appspot.com/bug?extid=3c8a843d9de82272915b > compiler: gcc (GCC) 8.0.1 20180413 (experimental) > > Unfortunately, I don't have any reproducer for this crash yet. > > IMPORTANT: if you fix the bug, please add the following tag to the commit: > Reported-by: syzbot+3c8a843d9de82272915b@xxxxxxxxxxxxxxxxxxxxxxxxx > > bond0: enslaved VLAN challenged slave lo. Adding VLANs will be blocked as > long as lo is part of bond bond0 > bond0: lo is up - this may be due to an out of date ifenslave > A link change request failed with some changes committed already. Interface > lo may have been left with an inconsistent configuration, please check. > BUG: please report to dccp@xxxxxxxxxxxxxxx => prev = 10, last = 10 at > net/dccp/ccids/lib/packet_history.c:425/tfrc_rx_hist_sample_rtt() > CPU: 0 PID: 9 Comm: ksoftirqd/0 Not tainted 4.20.0-rc6+ #374 > 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+0x244/0x39d lib/dump_stack.c:113 > tfrc_rx_hist_sample_rtt.cold.3+0x54/0x5c > net/dccp/ccids/lib/packet_history.c:422 > ccid3_hc_rx_packet_recv+0x5c4/0xeb0 net/dccp/ccids/ccid3.c:767 > ccid_hc_rx_packet_recv net/dccp/ccid.h:185 [inline] > dccp_deliver_input_to_ccids+0xf0/0x280 net/dccp/input.c:180 > dccp_rcv_established+0x87/0xb0 net/dccp/input.c:378 > dccp_v4_do_rcv+0x153/0x180 net/dccp/ipv4.c:656 > sk_backlog_rcv include/net/sock.h:932 [inline] > __sk_receive_skb+0x3e5/0xec0 net/core/sock.c:473 > dccp_v4_rcv+0x10f9/0x1f58 net/dccp/ipv4.c:877 > ip_local_deliver_finish+0x2e9/0xda0 net/ipv4/ip_input.c:215 > NF_HOOK include/linux/netfilter.h:289 [inline] > ip_local_deliver+0x1e9/0x750 net/ipv4/ip_input.c:256 > dst_input include/net/dst.h:450 [inline] > ip_rcv_finish+0x1f9/0x300 net/ipv4/ip_input.c:415 > NF_HOOK include/linux/netfilter.h:289 [inline] > ip_rcv+0xed/0x600 net/ipv4/ip_input.c:524 > __netif_receive_skb_one_core+0x14d/0x200 net/core/dev.c:4946 > __netif_receive_skb+0x2c/0x1e0 net/core/dev.c:5056 > process_backlog+0x24e/0x7a0 net/core/dev.c:5864 > napi_poll net/core/dev.c:6287 [inline] > net_rx_action+0x7fa/0x19b0 net/core/dev.c:6353 > __do_softirq+0x308/0xb7e kernel/softirq.c:292 > run_ksoftirqd+0x5e/0x100 kernel/softirq.c:654 > smpboot_thread_fn+0x68b/0xa00 kernel/smpboot.c:164 > kthread+0x35a/0x440 kernel/kthread.c:246 > ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352 > IPv6: ADDRCONF(NETDEV_CHANGE): vcan0: link becomes ready > IPVS: ftp: loaded support on port[0] = 21 > dccp_close: ABORT with 36864 bytes unread > bond0: enslaved VLAN challenged slave lo. Adding VLANs will be blocked as > long as lo is part of bond bond0 > bond0: lo is up - this may be due to an out of date ifenslave > A link change request failed with some changes committed already. Interface > lo may have been left with an inconsistent configuration, please check. > IPv6: ADDRCONF(NETDEV_CHANGE): vcan0: link becomes ready > IPv6: ADDRCONF(NETDEV_CHANGE): vcan0: link becomes ready > bond0: enslaved VLAN challenged slave lo. Adding VLANs will be blocked as > long as lo is part of bond bond0 > bond0: lo is up - this may be due to an out of date ifenslave > A link change request failed with some changes committed already. Interface > lo may have been left with an inconsistent configuration, please check. > IPVS: ftp: loaded support on port[0] = 21 > bond0: enslaved VLAN challenged slave lo. Adding VLANs will be blocked as > long as lo is part of bond bond0 > bond0: lo is up - this may be due to an out of date ifenslave > A link change request failed with some changes committed already. Interface > lo may have been left with an inconsistent configuration, please check. > IPv6: ADDRCONF(NETDEV_CHANGE): vcan0: link becomes ready > IPVS: ftp: loaded support on port[0] = 21 > IPv6: ADDRCONF(NETDEV_CHANGE): vcan0: link becomes ready > bond0: enslaved VLAN challenged slave lo. Adding VLANs will be blocked as > long as lo is part of bond bond0 > bond0: lo is up - this may be due to an out of date ifenslave > A link change request failed with some changes committed already. Interface > lo may have been left with an inconsistent configuration, please check. > IPv6: ADDRCONF(NETDEV_CHANGE): vcan0: link becomes ready > bond0: enslaved VLAN challenged slave lo. Adding VLANs will be blocked as > long as lo is part of bond bond0 > bond0: lo is up - this may be due to an out of date ifenslave > IPVS: ftp: loaded support on port[0] = 21 > A link change request failed with some changes committed already. Interface > lo may have been left with an inconsistent configuration, please check. > IPv6: ADDRCONF(NETDEV_CHANGE): vcan0: link becomes ready > bond0: enslaved VLAN challenged slave lo. Adding VLANs will be blocked as > long as lo is part of bond bond0 > bond0: lo is up - this may be due to an out of date ifenslave > A link change request failed with some changes committed already. Interface > lo may have been left with an inconsistent configuration, please check. > IPVS: ftp: loaded support on port[0] = 21 > IPv6: ADDRCONF(NETDEV_CHANGE): vcan0: link becomes ready > bond0: enslaved VLAN challenged slave lo. Adding VLANs will be blocked as > long as lo is part of bond bond0 > bond0: lo is up - this may be due to an out of date ifenslave > IPVS: ftp: loaded support on port[0] = 21 > A link change request failed with some changes committed already. Interface > lo may have been left with an inconsistent configuration, please check. > IPv6: ADDRCONF(NETDEV_CHANGE): vcan0: link becomes ready > IPVS: ftp: loaded support on port[0] = 21 > IPv6: ADDRCONF(NETDEV_CHANGE): vcan0: link becomes ready > bond0: enslaved VLAN challenged slave lo. Adding VLANs will be blocked as > long as lo is part of bond bond0 > bond0: lo is up - this may be due to an out of date ifenslave > IPVS: ftp: loaded support on port[0] = 21 > A link change request failed with some changes committed already. Interface > lo may have been left with an inconsistent configuration, please check. > IPv6: ADDRCONF(NETDEV_CHANGE): vcan0: link becomes ready > IPVS: ftp: loaded support on port[0] = 21 > IPv6: ADDRCONF(NETDEV_CHANGE): vcan0: link becomes ready > bond0: enslaved VLAN challenged slave lo. Adding VLANs will be blocked as > long as lo is part of bond bond0 > bond0: lo is up - this may be due to an out of date ifenslave > A link change request failed with some changes committed already. Interface > lo may have been left with an inconsistent configuration, please check. > IPVS: ftp: loaded support on port[0] = 21 > IPv6: ADDRCONF(NETDEV_CHANGE): vcan0: link becomes ready > bond0: enslaved VLAN challenged slave lo. Adding VLANs will be blocked as > long as lo is part of bond bond0 > bond0: lo is up - this may be due to an out of date ifenslave > A link change request failed with some changes committed already. Interface > lo may have been left with an inconsistent configuration, please check. > IPv6: ADDRCONF(NETDEV_CHANGE): vcan0: link becomes ready > IPv6: ADDRCONF(NETDEV_CHANGE): vcan0: link becomes ready > bond0: enslaved VLAN challenged slave lo. Adding VLANs will be blocked as > long as lo is part of bond bond0 > bond0: lo is up - this may be due to an out of date ifenslave > A link change request failed with some changes committed already. Interface > lo may have been left with an inconsistent configuration, please check. > > > --- > This bug is generated by a bot. It may contain errors. > See https://goo.gl/tpsmEJ for more information about syzbot. > syzbot engineers can be reached at syzkaller@xxxxxxxxxxxxxxxx. > > syzbot will keep track of this bug report. See: > https://goo.gl/tpsmEJ#bug-status-tracking for how to communicate with > syzbot. > > -- > You received this message because you are subscribed to the Google Groups "syzkaller-bugs" group. > To unsubscribe from this group and stop receiving emails from it, send an email to syzkaller-bugs+unsubscribe@xxxxxxxxxxxxxxxx. > To view this discussion on the web visit https://groups.google.com/d/msgid/syzkaller-bugs/0000000000007664bf057d71f6d7%40google.com. > For more options, visit https://groups.google.com/d/optout. #syz dup: BUG: please report to dccp@xxxxxxxxxxxxxxx => prev = 0, last = 0 at net/dccp/ccids/lib/packet_history.c:LINE/tfrc_rx_hist_sample_rtt() Still occurring, see existing thread with reproducer here: https://groups.google.com/d/msg/syzkaller-bugs/u5nq3PdPkIc/M7tbibYVCQAJ - Eric
