BUG: unable to handle kernel NULL pointer dereference at 0000000000000010 at clone_endio+0x34

Issue

• Kernel panic occurred with the following messages:

BUG: unable to handle kernel NULL pointer dereference at 0000000000000010
IP: [<ffffffffa0002444>] clone_endio+0x34/0xd0 [dm_mod]
PGD 8002d6067 PUD 7ff163067 PMD 0 
Oops: 0000 [#1] SMP 
last sysfs file: /sys/devices/system/cpu/online
CPU 0 
Modules linked in: autofs4 nfs lockd fscache auth_rpcgss nfs_acl sunrpc ipv6 ppdev parport_pc parport sg joydev microcode serio_raw xen_netfront i2c_piix4 i2c_core ext4 jbd2 mbcache sr_mod cdrom xen_blkfront pata_acpi ata_generic ata_piix dm_mirror dm_region_hash dm_log dm_mod [last unloaded: scsi_wait_scan]

Pid: 0, comm: swapper Not tainted 2.6.32-573.el6.x86_64 #1 Xen HVM domU
RIP: 0010:[<ffffffffa0002444>]  [<ffffffffa0002444>] clone_endio+0x34/0xd0 [dm_mod]
RSP: 0018:ffff880028203bc8  EFLAGS: 00010046
RAX: ffffffffa0002410 RBX: 0000000000000000 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffff880028203bf8 R08: ffff880452d42060 R09: 0000000000000000
R10: ffff8807fd6581c0 R11: ffff88002804d000 R12: ffff8804555c0cc0
R13: ffff8807fd6a7c00 R14: 0000000000000000 R15: ffff880804181700
FS:  0000000000000000(0000) GS:ffff880028200000(0000) knlGS:0000000000000000
CS:  0010 DS: 0018 ES: 0018 CR0: 000000008005003b
CR2: 0000000000000010 CR3: 00000007ff921000 CR4: 00000000001406f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Process swapper (pid: 0, threadinfo ffffffff81a00000, task ffffffff81a95020)
Stack:
 ffff880028203be8 ffff8804555c0cc0 0000000000000000 ffff880452d42060
<d> 0000000000000000 0000000000000000 ffff880028203c08 ffffffff811cbccd
<d> ffff880028203c38 ffffffff812729ab ffff880028203c68 ffff8804555c0cc0
Call Trace:
 <IRQ> 
 [<ffffffff811cbccd>] bio_endio+0x1d/0x40
 [<ffffffff812729ab>] req_bio_endio+0x9b/0xe0
 [<ffffffff81273ef7>] blk_update_request+0x117/0x4c0
 [<ffffffff812742c7>] blk_update_bidi_request+0x27/0xa0
 [<ffffffff812753de>] __blk_end_request_all+0x2e/0x60
 [<ffffffff81279771>] blk_flush_complete_seq+0x251/0x290
 [<ffffffff812799e5>] flush_end_io+0x115/0x1b0
 [<ffffffff812751eb>] blk_finish_request+0x9b/0x260
 [<ffffffff813351de>] ? add_disk_randomness+0x2e/0x30
 [<ffffffff812753fb>] __blk_end_request_all+0x4b/0x60
 [<ffffffffa004f67a>] blkif_interrupt+0x64a/0x860 [xen_blkfront]
 [<ffffffff810ed980>] handle_IRQ_event+0x60/0x170
 [<ffffffff810f02ee>] handle_edge_irq+0xde/0x180
 [<ffffffff8132a469>] __xen_evtchn_do_upcall+0x1b9/0x1f0
 [<ffffffff8132aa3f>] xen_evtchn_do_upcall+0x2f/0x50
 [<ffffffff8100c4b3>] xen_hvm_callback_vector+0x13/0x20
 <EOI> 
 [<ffffffff8104301b>] ? native_safe_halt+0xb/0x10
 [<ffffffff810167ed>] default_idle+0x4d/0xb0
 [<ffffffff81009fe6>] cpu_idle+0xb6/0x110
 [<ffffffff8151ee5a>] rest_init+0x7a/0x80
 [<ffffffff81c38122>] start_kernel+0x424/0x431
 [<ffffffff81c3733a>] x86_64_start_reservations+0x125/0x129
 [<ffffffff81c37453>] x86_64_start_kernel+0x115/0x124
Code: 89 5d d8 4c 89 65 e0 4c 89 6d e8 4c 89 75 f0 4c 89 7d f8 0f 1f 44 00 00 4c 8b 6f 58 49 89 fc 85 f6 89 f3 49 8b 7d 08 4d 8b 7d 00 <48> 8b 47 10 4d 8b 37 48 8b 40 48 75 0e 41 f6 44 24 18 01 ba fb 
RIP  [<ffffffffa0002444>] clone_endio+0x34/0xd0 [dm_mod]
 RSP <ffff880028203bc8>
CR2: 0000000000000010
---[ end trace bd921e8389362d94 ]---