Re: [ros-dev] [ros-diffs] [hbelusca] 57504: [NTOSKRNL] Rearrange the NtQuerySystemEnvironmentValue code to have successive logical checks.

[Timo Kreuzer]

This changes the logic. I'm not sure how exact the previous version was, 
but these changes should be tested.


Am 06.10.2012 21:50, schrieb hbelusca(a)svn.reactos.org:
>   Author: hbelusca
>  Date: Sat Oct  6 19:50:17 2012
>  New Revision: 57504
>
>  URL: http://svn.reactos.org/svn/reactos?rev=57504&view=rev
>  Log:
>  [NTOSKRNL]
>  Rearrange the NtQuerySystemEnvironmentValue code to have successive logical checks.
>
>  Modified:
>       trunk/reactos/ntoskrnl/ex/sysinfo.c
>
>  Modified: trunk/reactos/ntoskrnl/ex/sysinfo.c
>  URL:
> http://svn.reactos.org/svn/reactos/trunk/reactos/ntoskrnl/ex/sysinfo.c?rev=…
>  ==============================================================================
>  --- trunk/reactos/ntoskrnl/ex/sysinfo.c [iso-8859-1] (original)
>  +++ trunk/reactos/ntoskrnl/ex/sysinfo.c [iso-8859-1] Sat Oct  6 19:50:17 2012
>  @@ -235,44 +235,40 @@
>                _SEH2_YIELD(return _SEH2_GetExceptionCode());
>            }
>            _SEH2_END;
>  -
>  -    }
>  -
>  -    /* Allocate a buffer for the value */
>  -    AnsiValueBuffer = ExAllocatePoolWithTag(NonPagedPool, ValueBufferLength,
> 'pmeT');
>  -    if (AnsiValueBuffer == NULL)
>  -    {
>  -        return STATUS_INSUFFICIENT_RESOURCES;
>  -    }
>  -
>  -    /*
>  -     * Copy the name to kernel space if necessary and convert it to ANSI.
>  -     */
>  +    }
>  +
>  +    /* According to NTInternals the SeSystemEnvironmentName privilege is required! */
>  +    if (!SeSinglePrivilegeCheck(SeSystemEnvironmentPrivilege, PreviousMode))
>  +    {
>  +        DPRINT1("NtQuerySystemEnvironmentValue: Caller requires the
> SeSystemEnvironmentPrivilege privilege!\n");
>  +        return STATUS_PRIVILEGE_NOT_HELD;
>  +    }
>  +
>  +    /* Copy the name to kernel space if necessary */
>        Status = ProbeAndCaptureUnicodeString(&WName, PreviousMode, VariableName);
>        if (!NT_SUCCESS(Status))
>        {
>            return Status;
>        }
>    
>  -    /*
>  -     * according to ntinternals the SeSystemEnvironmentName privilege is required!
>  -     */
>  -    if (!SeSinglePrivilegeCheck(SeSystemEnvironmentPrivilege, PreviousMode))
>  -    {
>  -        ReleaseCapturedUnicodeString(&WName, PreviousMode);
>  -        DPRINT1("NtQuerySystemEnvironmentValue: Caller requires the
> SeSystemEnvironmentPrivilege privilege!\n");
>  -        return STATUS_PRIVILEGE_NOT_HELD;
>  -    }
>  -
>  -    /* Convert the value name to ansi and release the captured unicode string */
>  +    /* Convert the name to ANSI and release the captured UNICODE string */
>        Status = RtlUnicodeStringToAnsiString(&AName, &WName, TRUE);
>        ReleaseCapturedUnicodeString(&WName, PreviousMode);
>        if (!NT_SUCCESS(Status)) return Status;
>    
>  -    /* Get the environment variable */
>  +    /* Allocate a buffer for the ANSI environment variable */
>  +    AnsiValueBuffer = ExAllocatePoolWithTag(NonPagedPool, ValueBufferLength,
> 'pmeT');
>  +    if (AnsiValueBuffer == NULL)
>  +    {
>  +        RtlFreeAnsiString(&AName);
>  +        return STATUS_INSUFFICIENT_RESOURCES;
>  +    }
>  +
>  +    /* Get the environment variable and free the ANSI name */
>        Result = HalGetEnvironmentVariable(AName.Buffer,
>                                           (USHORT)ValueBufferLength,
>                                           AnsiValueBuffer);
>  +    RtlFreeAnsiString(&AName);
>    
>        /* Check if we had success */
>        if (Result == ESUCCESS)
>  @@ -280,13 +276,13 @@
>            /* Copy the result back to the caller. */
>            _SEH2_TRY
>            {
>  -            /* Initialize ansi string from the result */
>  +            /* Initialize ANSI string from the result */
>                RtlInitAnsiString(&AValue, AnsiValueBuffer);
>    
>  -            /* Initialize a unicode string from the callers buffer */
>  +            /* Initialize a UNICODE string from the callers buffer */
>                RtlInitEmptyUnicodeString(&WValue, ValueBuffer, ValueBufferLength);
>    
>  -            /* Convert the result to unicode */
>  +            /* Convert the result to UNICODE */
>                Status = RtlAnsiStringToUnicodeString(&WValue, &AValue, FALSE);
>    
>                if (ReturnLength != NULL)
>  @@ -305,8 +301,7 @@
>            Status = STATUS_UNSUCCESSFUL;
>        }
>    
>  -    /* Cleanup allocated resources. */
>  -    RtlFreeAnsiString(&AName);
>  +    /* Free the allocated ANSI value buffer */
>        ExFreePoolWithTag(AnsiValueBuffer, 'pmeT');
>    
>        return Status;
>
>
>