Unable to handle kernel NULL pointer dereference at virtual address 00000000
 printing eip:
c021a1fd
*pde = 00000000
Oops: 0000 [#1]
PREEMPT 
CPU:    0
EIP:    0060:[<c021a1fd>]    Not tainted VLI
EFLAGS: 00010246
EIP is at generic_ide_ioctl+0x30d/0x7a0
eax: 00000000   ebx: bffffb68   ecx: f7ff1040   edx: 00000000
esi: bffffb60   edi: 00000ced   ebp: f7577f68   esp: f7577f38
ds: 007b   es: 007b   ss: 0068
Process fdisk (pid: 398, threadinfo=f7576000 task=f7628670)
Stack: c0326f5f 0000064e 00000000 000b2345 c043f4a8 f7577f68 401363a8 bffffb00 
       f7577fbc f7ff1040 bffffb60 f759d0fc f7577f90 c0202a90 f7ff1040 00000301 
       bffffb60 bffffb60 00002200 00000301 f76043c0 ffffffe7 f7577fbc c016d5c4 
Call Trace:
 [<c0202a90>] blkdev_ioctl+0x90/0x3ca
 [<c016d5c4>] sys_ioctl+0xf4/0x2b0
 [<c02fe977>] syscall_call+0x7/0xb

Code: 00 00 c7 04 24 5f 6f 32 c0 e8 30 64 f0 ff 83 c3 04 83 c3 04 19 c0 39 5e 18 83 d8 00 85 c0 75 1a 8b 4d 08 31 c0 8b 75 10 8b 51 38 <8b> 12 89 56 04 31 d2 85 c0 0f 84 61 fd ff ff ba f2 ff ff ff e9