1: kd> .bugcheck
Bugcheck code 000000C2
Arguments 00000000`00000007 00000000`00001200 00000000`0502030a ffffc001`928dbce0
//Pool block being freed twice
1: kd> k
Child-SP RetAddr Call Site
ffffd001`393507a8 fffff801`496aef56 nt!KeBugCheckEx
ffffd001`393507b0 fffff801`6abcc75e nt!ExFreePool+0x26a
ffffd001`393508a0 ffffe001`dfa43200 ctxusbm+0x1375e
ffffd001`393508a8 ffffe001`dfa43010 0xffffe001`dfa43200
ffffd001`393508b0 00000000`de060000 0xffffe001`dfa43010
ffffd001`393508b8 ffffd001`00000002 0xde060000
ffffd001`393508c0 ffffd001`393508b8 0xffffd001`00000002
ffffd001`393508c8 00000000`e000071b 0xffffd001`393508b8
ffffd001`393508d0 00000000`00000000 0xe000071b
1: kd> !pool ffffc001928dbce0
Pool page ffffc001928dbce0 region is Unknown
ffffc001928db000 size: 510 previous size: 0 (Allocated) Ntff
ffffc001928db510 size: 30 previous size: 510 (Allocated) Ntf0
ffffc001928db540 size: 10 previous size: 30 (Free) Free
ffffc001928db550 size: 40 previous size: 10 (Allocated) GDmp
ffffc001928db590 size: 40 previous size: 40 (Allocated) GDmp
ffffc001928db5d0 size: 160 previous size: 40 (Allocated) FMfn
ffffc001928db730 size: 40 previous size: 160 (Allocated) GDmp
ffffc001928db770 size: b0 previous size: 40 (Allocated) CMNb
ffffc001928db820 size: 10 previous size: b0 (Free) Free
ffffc001928db830 size: 40 previous size: 10 (Allocated) NtFs
ffffc001928db870 size: 30 previous size: 40 (Allocated) Ntf0
ffffc001928db8a0 size: 70 previous size: 30 (Allocated) AtmA
ffffc001928db910 size: 20 previous size: 70 (Free) Free
ffffc001928db930 size: 60 previous size: 20 (Allocated) GDKx
ffffc001928db990 size: 10 previous size: 60 (Free) Free
ffffc001928db9a0 size: 40 previous size: 10 (Allocated) GDmp
ffffc001928db9e0 size: 40 previous size: 40 (Allocated) GDmp
ffffc001928dba20 size: a0 previous size: 40 (Free ) Sect
ffffc001928dbac0 size: a0 previous size: a0 (Free) DxgK
ffffc001928dbb60 size: 90 previous size: a0 (Allocated) FSim
ffffc001928dbbf0 size: 40 previous size: 90 (Allocated) Ppsu
ffffc001928dbc30 size: a0 previous size: 40 (Free) Sect
*ffffc001928dbcd0 size: 20 previous size: a0 (Free ) *CTXf
Owning component : Unknown (update pooltag.txt)
ffffc001928dbcf0 size: 60 previous size: 20 (Free) CMpb
ffffc001928dbd50 size: 30 previous size: 60 (Allocated) GDbv
ffffc001928dbd80 size: 40 previous size: 30 (Free ) ObHd
ffffc001928dbdc0 size: 30 previous size: 40 (Allocated) Ntf0
ffffc001928dbdf0 size: 210 previous size: 30 (Allocated) FMfn
1: kd> dc 502030a
00000000`0502030a ???????? ???????? ???????? ???????? ????????????????
00000000`0502031a ???????? ???????? ???????? ???????? ????????????????
00000000`0502032a ???????? ???????? ???????? ???????? ????????????????
00000000`0502033a ???????? ???????? ???????? ???????? ????????????????
00000000`0502034a ???????? ???????? ???????? ???????? ????????????????
00000000`0502035a ???????? ???????? ???????? ???????? ????????????????
00000000`0502036a ???????? ???????? ???????? ???????? ????????????????
00000000`0502037a ???????? ???????? ???????? ???????? ????????????????
1: kd> lmvm ctxusbm
start end module name
fffff801`6abb9000 fffff801`6abd7200 ctxusbm T (no symbols)
Loaded symbol image file: ctxusbm.sys
Image path: \SystemRoot\system32\DRIVERS\ctxusbm.sys
Image name: ctxusbm.sys
Timestamp: Mon Oct 13 11:19:50 2014 (543BA746)
CheckSum: 000224A3
ImageSize: 0001E200
Translations: 0000.04b0 0000.04e4 0409.04b0 0409.04e4