How to find Invalid Nonpaged memory address?
in [Device Drivers]
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From: ShivaP on 29 Apr 2008 02:41 Hi.. I have allocated memory from Nonpaged pool using ExAllocatePoolWithTag. I am passing the pointer to the allocated memory location into a function call, and sometime when tried to access the same, gives a SYSTEM_THREAD_EXCEPTION_NOT_HANDLED (7e) The allocated memory is not freed. The access violation happends randomly.. EXCEPTION_RECORD: badd0b3c -- (.exr ffffffffbadd0b3c) ExceptionAddress: b9ceb90c (mydriver!MyBox::MyBoxType+0x0000000c) ExceptionCode: c0000005 (Access violation) ExceptionFlags: 00000000 NumberParameters: 2 Parameter[0]: 00000000 Parameter[1]: 004d98a4 Attempt to read from address 004d98a4 Is there any way find out whether the address in the Nonpaged is valid or not.. I tried using MmIsAddressValid, it's mentioned in documentation that it's not recommended to use it.. also I am not able to compile with WDK 6000 build. Thanks..
From: Gianluca Varenni on 29 Apr 2008 11:52 "ShivaP" <ShivaP(a)discussions.microsoft.com> wrote in message news:C82E4ABB-8134-4AD8-AA01-A58E783FFBD9(a)microsoft.com... > Hi.. > > I have allocated memory from Nonpaged pool using ExAllocatePoolWithTag. > > I am passing the pointer to the allocated memory location into a function > call, and sometime when tried to access the same, gives a > SYSTEM_THREAD_EXCEPTION_NOT_HANDLED (7e) > > The allocated memory is not freed. The access violation happends > randomly.. > > EXCEPTION_RECORD: badd0b3c -- (.exr ffffffffbadd0b3c) > ExceptionAddress: b9ceb90c (mydriver!MyBox::MyBoxType+0x0000000c) > ExceptionCode: c0000005 (Access violation) > ExceptionFlags: 00000000 > NumberParameters: 2 > Parameter[0]: 00000000 > Parameter[1]: 004d98a4 > Attempt to read from address 004d98a4 > > Is there any way find out whether the address in the Nonpaged is valid or > not.. > No. If you are responsible for allocating/freeing that memory, you need to find out why that memory becomes invalid randomly. MmIsAddressValid is useless. By the time that function returns (and maybe tells you that the memory is valid) some other code in your driver (another thread? a dispatch routine?) can have freed that same chunk of memory. Have you tried turning the verifier on and see if it catches any issue? Hope it helps GV -- Gianluca Varenni, Windows DDK MVP CACE Technologies http://www.cacetech.com > I tried using MmIsAddressValid, it's mentioned in documentation that it's > not recommended to use it.. also I am not able to compile with WDK 6000 > build. > > Thanks..
From: Ivan Brugiolo [MSFT] on 5 May 2008 13:22
The address `004d98a4` does look like a user-mode address. Are you using the `Probe` macros and memcpy in a __try/__except in your user-to-kernel entry-point ? On average, you should either create a kernl copy of a structure, if small, or lock pages and create adequate mappings. -- -- This posting is provided "AS IS" with no warranties, and confers no rights. Use of any included script samples are subject to the terms specified at http://www.microsoft.com/info/cpyright.htm "ShivaP" <ShivaP(a)discussions.microsoft.com> wrote in message news:C82E4ABB-8134-4AD8-AA01-A58E783FFBD9(a)microsoft.com... > Hi.. > > I have allocated memory from Nonpaged pool using ExAllocatePoolWithTag. > > I am passing the pointer to the allocated memory location into a function > call, and sometime when tried to access the same, gives a > SYSTEM_THREAD_EXCEPTION_NOT_HANDLED (7e) > > The allocated memory is not freed. The access violation happends > randomly.. > > EXCEPTION_RECORD: badd0b3c -- (.exr ffffffffbadd0b3c) > ExceptionAddress: b9ceb90c (mydriver!MyBox::MyBoxType+0x0000000c) > ExceptionCode: c0000005 (Access violation) > ExceptionFlags: 00000000 > NumberParameters: 2 > Parameter[0]: 00000000 > Parameter[1]: 004d98a4 > Attempt to read from address 004d98a4 > > Is there any way find out whether the address in the Nonpaged is valid or > not.. > > I tried using MmIsAddressValid, it's mentioned in documentation that it's > not recommended to use it.. also I am not able to compile with WDK 6000 > build. > > Thanks.. |