<div>Hello,</div><div><br></div><div>Just recently saw this message in my syslog, using drbd 8.4.1. As you can also see I'm runing as Xen dom0. The crash seems to be in the ip_route_output_slow call... is this a kernel bug or a drbd problem? I also attached the error in a text file for convenience.</div>
<div><br></div><div>I noticed that Lars patched drbd 8.3 with a comment regarding a null pointer dereference, could this be that issue? I really would love to use 8.3, but I'm reliant on the drbd volume minor numbers going above 255. Would anyone possibly know a way to tweak 8.3 to allow larger minor numbers?</div>
<div><br></div><div>Thanks,</div><div><br></div><div>Chris</div><div><br></div><div>The error:</div><div><br></div><div>Jun 26 10:17:45 vicks0 kernel: [239010.496650] BUG: unable to handle kernel NULL pointer dereference at 00000000000000c0</div>
<div>Jun 26 10:17:45 vicks0 kernel: [239010.496814] IP: [<ffffffff815707d5>] ip_route_output_slow+0x345/0x540</div><div>Jun 26 10:17:45 vicks0 kernel: [239010.496908] PGD 1ecb894067 PUD 1ecaf06067 PMD 0</div><div>Jun 26 10:17:45 vicks0 kernel: [239010.496996] Oops: 0000 [#1] SMP</div>
<div>Jun 26 10:17:45 vicks0 kernel: [239010.497069] CPU 1</div><div>Jun 26 10:17:45 vicks0 kernel: [239010.497080] Modules linked in: iptable_nat nf_nat nf_conntrack_ipv4 nf_conntrack nf_defrag_ipv4 ebt_arp ebt_ip xt_physdev iptable_filter ip_tables drbd(O) libcrc32c bonding ebtable_broute bridge stp ebtable_filter ebtables x_tables psmouse amd64_edac_mod serio_raw edac_core fam15h_power joydev sp5100_tco edac_mce_amd k10temp i2c_piix4 xen_wdt mac_hid xen_pciback xen_netback xen_gntdev xen_gntalloc xenfs xen_evtchn xen_blkback lp parport dm_snapshot usbhid hid mpt2sas(O) pata_atiixp scsi_transport_sas raid_class ixgbe(O) dca e1000e</div>
<div>Jun 26 10:17:45 vicks0 kernel: [239010.497877]</div><div>Jun 26 10:17:45 vicks0 kernel: [239010.497931] Pid: 27041, comm: drbd_r_r4537 Tainted: G O 3.2.0-23-generic #36-Ubuntu ASUSTeK Computer INC. KGP(M)E-D16/KGP(M)E-D16</div>
<div>Jun 26 10:17:45 vicks0 kernel: [239010.498084] RIP: e030:[<ffffffff815707d5>] [<ffffffff815707d5>] ip_route_output_slow+0x345/0x540</div><div>Jun 26 10:17:45 vicks0 kernel: [239010.498210] RSP: e02b:ffff8809ef679820 EFLAGS: 00010246</div>
<div>Jun 26 10:17:45 vicks0 kernel: [239010.498281] RAX: 0000000000000000 RBX: ffff8809f0d14658 RCX: 0000000000000000</div><div>Jun 26 10:17:45 vicks0 kernel: [239010.498395] RDX: ffff880c7801f440 RSI: 0000000000000000 RDI: ffff880c7801f440</div>
<div>Jun 26 10:17:45 vicks0 kernel: [239010.498509] RBP: ffff8809ef6798b0 R08: 00000000ac1111b9 R09: 0000000000000000</div><div>Jun 26 10:17:45 vicks0 kernel: [239010.498624] R10: ffff8809ef679858 R11: 00000000ac1111b9 R12: 00000000b91110ac</div>
<div>Jun 26 10:17:45 vicks0 kernel: [239010.498738] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000</div><div>Jun 26 10:17:45 vicks0 kernel: [239010.498857] FS: 00007f0fa16c1700(0000) GS:ffff881f9e0aa000(0000) knlGS:0000000000000000</div>
<div>Jun 26 10:17:45 vicks0 kernel: [239010.498976] CS: e033 DS: 0000 ES: 0000 CR0: 000000008005003b</div><div>Jun 26 10:17:45 vicks0 kernel: [239010.499048] CR2: 00000000000000c0 CR3: 0000001ec6b02000 CR4: 0000000000000660</div>
<div>Jun 26 10:17:45 vicks0 kernel: [239010.499167] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000</div><div>Jun 26 10:17:45 vicks0 kernel: [239010.499282] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400</div>
<div>Jun 26 10:17:45 vicks0 kernel: [239010.499397] Process drbd_r_r4537 (pid: 27041, threadinfo ffff8809ef678000, task ffff881ecd352de0)</div><div>Jun 26 10:17:45 vicks0 kernel: [239010.499519] Stack:</div><div>Jun 26 10:17:45 vicks0 kernel: [239010.499573] ffff8809ef679840 ffffffff81578909 ffff8809f25d9f00 ffff8809ef679858</div>
<div>Jun 26 10:17:45 vicks0 kernel: [239010.499708] ffff880900000000 b91111ac81578a6c ffff8809ef679860 ffff8809fd010010</div><div>Jun 26 10:17:45 vicks0 kernel: [239010.499842] ffff880c7801f440 ffff881ec7d8a440 ffff8809eb336598 ffff881ec9e15140</div>
<div>Jun 26 10:17:45 vicks0 kernel: [239010.499977] Call Trace:</div><div>Jun 26 10:17:45 vicks0 kernel: [239010.500040] [<ffffffff81578909>] ? ip_local_out+0x29/0x30</div><div>Jun 26 10:17:45 vicks0 kernel: [239010.500069] [<ffffffff815718a0>] __ip_route_output_key+0xb0/0x1b0</div>
<div>Jun 26 10:17:45 vicks0 kernel: [239010.500069] [<ffffffff815719c7>] ip_route_output_flow+0x27/0x70</div><div>Jun 26 10:17:45 vicks0 kernel: [239010.500069] [<ffffffff81578cbe>] ip_queue_xmit+0x3ae/0x410</div>
<div>Jun 26 10:17:45 vicks0 kernel: [239010.500069] [<ffffffff81590d99>] tcp_transmit_skb+0x359/0x580</div><div>Jun 26 10:17:45 vicks0 kernel: [239010.500069] [<ffffffff815926ac>] tcp_send_ack+0x8c/0xe0</div>
<div>Jun 26 10:17:45 vicks0 kernel: [239010.500069] [<ffffffff81583680>] tcp_cleanup_rbuf+0x70/0x120</div><div>Jun 26 10:17:45 vicks0 kernel: [239010.500069] [<ffffffff8158457b>] tcp_recvmsg+0x63b/0xba0</div>
<div>Jun 26 10:17:45 vicks0 kernel: [239010.500069] [<ffffffff815a853b>] inet_recvmsg+0x6b/0x80</div><div>Jun 26 10:17:45 vicks0 kernel: [239010.500069] [<ffffffff8165c579>] ? _raw_spin_unlock_bh+0x19/0x20</div>
<div>Jun 26 10:17:45 vicks0 kernel: [239010.500069] [<ffffffff8152780d>] sock_recvmsg+0x11d/0x140</div><div>Jun 26 10:17:45 vicks0 kernel: [239010.500069] [<ffffffff8100a29d>] ? xen_force_evtchn_callback+0xd/0x10</div>
<div>Jun 26 10:17:45 vicks0 kernel: [239010.500069] [<ffffffff8100aa82>] ? check_events+0x12/0x20</div><div>Jun 26 10:17:45 vicks0 kernel: [239010.500069] [<ffffffff8100aa6f>] ? xen_restore_fl_direct_reloc+0x4/0x4</div>
<div>Jun 26 10:17:45 vicks0 kernel: [239010.500069] [<ffffffff81004c62>] ? xen_mc_flush+0xb2/0x1c0</div><div>Jun 26 10:17:45 vicks0 kernel: [239010.500069] [<ffffffff81003ec3>] ? xen_write_msr_safe+0xa3/0xc0</div>
<div>Jun 26 10:17:45 vicks0 kernel: [239010.500069] [<ffffffff81012728>] ? __switch_to+0x138/0x360</div><div>Jun 26 10:17:45 vicks0 kernel: [239010.500069] [<ffffffffa0217712>] drbd_recv+0x82/0x140 [drbd]</div>
<div>Jun 26 10:17:45 vicks0 kernel: [239010.500069] [<ffffffffa02177e6>] drbd_recv_all+0x16/0x40 [drbd]</div><div>Jun 26 10:17:45 vicks0 kernel: [239010.500069] [<ffffffffa0217834>] drbd_recv_all_warn+0x24/0x70 [drbd]</div>
<div>Jun 26 10:17:45 vicks0 kernel: [239010.500069] [<ffffffffa021a93f>] read_in_block+0x16f/0x350 [drbd]</div><div>Jun 26 10:17:45 vicks0 kernel: [239010.500069] [<ffffffffa0217712>] ? drbd_recv+0x82/0x140 [drbd]</div>
<div>Jun 26 10:17:45 vicks0 kernel: [239010.500069] [<ffffffffa021b979>] recv_resync_read+0x29/0x230 [drbd]</div><div>Jun 26 10:17:45 vicks0 kernel: [239010.500069] [<ffffffffa021bc1c>] receive_RSDataReply+0x9c/0x250 [drbd]</div>
<div>Jun 26 10:17:45 vicks0 kernel: [239010.500069] [<ffffffffa0217834>] ? drbd_recv_all_warn+0x24/0x70 [drbd]</div><div>Jun 26 10:17:45 vicks0 kernel: [239010.500069] [<ffffffffa021f8d6>] drbdd+0xb6/0x170 [drbd]</div>
<div>Jun 26 10:17:45 vicks0 kernel: [239010.500069] [<ffffffffa0220e30>] drbdd_init+0x40/0xb0 [drbd]</div><div>Jun 26 10:17:45 vicks0 kernel: [239010.500069] [<ffffffffa02294c9>] drbd_thread_setup+0xa9/0x160 [drbd]</div>
<div>Jun 26 10:17:45 vicks0 kernel: [239010.500069] [<ffffffff81056183>] ? finish_task_switch+0x53/0xf0</div><div>Jun 26 10:17:45 vicks0 kernel: [239010.500069] [<ffffffff81666bf4>] kernel_thread_helper+0x4/0x10</div>
<div>Jun 26 10:17:45 vicks0 kernel: [239010.500069] [<ffffffff81664ca3>] ? int_ret_from_sys_call+0x7/0x1b</div><div>Jun 26 10:17:45 vicks0 kernel: [239010.500069] [<ffffffff8165c97c>] ? retint_restore_args+0x5/0x6</div>
<div>Jun 26 10:17:45 vicks0 kernel: [239010.500069] [<ffffffff81666bf0>] ? gs_change+0x13/0x13</div><div>Jun 26 10:17:45 vicks0 kernel: [239010.500069] Code: 83 79 18 01 7e 08 3c 01 0f 84 da 01 00 00 44 8b 6b 18 45 85 ed 0f 84 db 00 00 00 0f b6 4d a9 48 8d 04 c9 45 31 ff 4c 8b 6c c2 60 <41> 8b 85 c0 00 00 00 89 03 e9 cf fd ff ff 0f 1f 44 00 00 31 d2</div>
<div>Jun 26 10:17:45 vicks0 kernel: [239010.500069] RIP [<ffffffff815707d5>] ip_route_output_slow+0x345/0x540</div><div>Jun 26 10:17:45 vicks0 kernel: [239010.500069] RSP <ffff8809ef679820></div><div>Jun 26 10:17:45 vicks0 kernel: [239010.500069] CR2: 00000000000000c0</div>
<div>Jun 26 10:17:45 vicks0 kernel: [239010.500069] ---[ end trace 903d87b699d75f9f ]---</div>