[reactos] 01/01: [NTOS:SE] Remove redundant ReturnLength NULL check

[George Bișoc]

https://git.reactos.org/?p=reactos.git;a=commitdiff;h=93381263a1f3bfffe70f7…

commit 93381263a1f3bfffe70f72bd63944bdff62f93e8
Author:     George Bișoc <george.bisoc(a)reactos.org>
AuthorDate: Mon Jun 13 19:28:12 2022 +0200
Commit:     George Bișoc <george.bisoc(a)reactos.org>
CommitDate: Mon Jun 13 19:28:12 2022 +0200

    [NTOS:SE] Remove redundant ReturnLength NULL check
    
    In NtQueryInformationToken function, remove the useless and redundant NULL check for
two primary reasons. First, DefaultQueryInfoBufferCheck already does the necessary probing
validation checks and second, ReturnLength must NEVER be NULL!
    If the caller does not respect the calling rules of NtQueryInformationToken, the
caller is expected to be miserably punished.
---
 ntoskrnl/se/tokencls.c | 78 ++++++++++++++------------------------------------
 1 file changed, 21 insertions(+), 57 deletions(-)

diff --git a/ntoskrnl/se/tokencls.c b/ntoskrnl/se/tokencls.c
index 50e81a9a453..2a6806ba3d8 100644
--- a/ntoskrnl/se/tokencls.c
+++ b/ntoskrnl/se/tokencls.c
@@ -450,8 +450,11 @@ SeQueryInformationToken(
  * Length of the token information buffer, in bytes.
  *
  * @param[out] ReturnLength
- * If specified in the call, the function returns the total length size of the token
- * information buffer..
+ * A pointer to a variable provided by the caller that receives the actual length
+ * of the buffer pointed by TokenInformation, in bytes. If TokenInformation is NULL
+ * and TokenInformationLength is 0, this parameter receives the required length
+ * needed to store the buffer information in memory. This parameter must not
+ * be NULL!
  *
  * @return
  * Returns STATUS_SUCCESS if information querying has completed successfully.
@@ -459,8 +462,9 @@ SeQueryInformationToken(
  * the token information buffer is not greater than the required length.
  * STATUS_INVALID_HANDLE is returned if the token handle is not a valid one.
  * STATUS_INVALID_INFO_CLASS is returned if the information class is not a valid
- * one (that is, the class doesn't belong to TOKEN_INFORMATION_CLASS). A failure
- * NTSTATUS code is returned otherwise.
+ * one (that is, the class doesn't belong to TOKEN_INFORMATION_CLASS).
+ * STATUS_ACCESS_VIOLATION is returned if ReturnLength is NULL. A failure NTSTATUS
+ * code is returned otherwise.
  */
 _Must_inspect_result_
 __kernel_entry
@@ -542,10 +546,7 @@ NtQueryInformationToken(
                         Status = STATUS_BUFFER_TOO_SMALL;
                     }
 
-                    if (ReturnLength != NULL)
-                    {
-                        *ReturnLength = RequiredLength;
-                    }
+                    *ReturnLength = RequiredLength;
                 }
                 _SEH2_EXCEPT(EXCEPTION_EXECUTE_HANDLER)
                 {
@@ -587,10 +588,7 @@ NtQueryInformationToken(
                         Status = STATUS_BUFFER_TOO_SMALL;
                     }
 
-                    if (ReturnLength != NULL)
-                    {
-                        *ReturnLength = RequiredLength;
-                    }
+                    *ReturnLength = RequiredLength;
                 }
                 _SEH2_EXCEPT(EXCEPTION_EXECUTE_HANDLER)
                 {
@@ -623,10 +621,7 @@ NtQueryInformationToken(
                         Status = STATUS_BUFFER_TOO_SMALL;
                     }
 
-                    if (ReturnLength != NULL)
-                    {
-                        *ReturnLength = RequiredLength;
-                    }
+                    *ReturnLength = RequiredLength;
                 }
                 _SEH2_EXCEPT(EXCEPTION_EXECUTE_HANDLER)
                 {
@@ -660,10 +655,7 @@ NtQueryInformationToken(
                         Status = STATUS_BUFFER_TOO_SMALL;
                     }
 
-                    if (ReturnLength != NULL)
-                    {
-                        *ReturnLength = RequiredLength;
-                    }
+                   *ReturnLength = RequiredLength;
                 }
                 _SEH2_EXCEPT(EXCEPTION_EXECUTE_HANDLER)
                 {
@@ -697,10 +689,7 @@ NtQueryInformationToken(
                         Status = STATUS_BUFFER_TOO_SMALL;
                     }
 
-                    if (ReturnLength != NULL)
-                    {
-                        *ReturnLength = RequiredLength;
-                    }
+                    *ReturnLength = RequiredLength;
                 }
                 _SEH2_EXCEPT(EXCEPTION_EXECUTE_HANDLER)
                 {
@@ -742,10 +731,7 @@ NtQueryInformationToken(
                         Status = STATUS_BUFFER_TOO_SMALL;
                     }
 
-                    if (ReturnLength != NULL)
-                    {
-                        *ReturnLength = RequiredLength;
-                    }
+                    *ReturnLength = RequiredLength;
                 }
                 _SEH2_EXCEPT(EXCEPTION_EXECUTE_HANDLER)
                 {
@@ -774,10 +760,7 @@ NtQueryInformationToken(
                         Status = STATUS_BUFFER_TOO_SMALL;
                     }
 
-                    if (ReturnLength != NULL)
-                    {
-                        *ReturnLength = RequiredLength;
-                    }
+                   *ReturnLength = RequiredLength;
                 }
                 _SEH2_EXCEPT(EXCEPTION_EXECUTE_HANDLER)
                 {
@@ -806,10 +789,7 @@ NtQueryInformationToken(
                         Status = STATUS_BUFFER_TOO_SMALL;
                     }
 
-                    if (ReturnLength != NULL)
-                    {
-                        *ReturnLength = RequiredLength;
-                    }
+                    *ReturnLength = RequiredLength;
                 }
                 _SEH2_EXCEPT(EXCEPTION_EXECUTE_HANDLER)
                 {
@@ -846,10 +826,7 @@ NtQueryInformationToken(
                         Status = STATUS_BUFFER_TOO_SMALL;
                     }
 
-                    if (ReturnLength != NULL)
-                    {
-                        *ReturnLength = RequiredLength;
-                    }
+                    *ReturnLength = RequiredLength;
                 }
                 _SEH2_EXCEPT(EXCEPTION_EXECUTE_HANDLER)
                 {
@@ -887,10 +864,7 @@ NtQueryInformationToken(
                         Status = STATUS_BUFFER_TOO_SMALL;
                     }
 
-                    if (ReturnLength != NULL)
-                    {
-                        *ReturnLength = RequiredLength;
-                    }
+                    *ReturnLength = RequiredLength;
                 }
                 _SEH2_EXCEPT(EXCEPTION_EXECUTE_HANDLER)
                 {
@@ -919,10 +893,7 @@ NtQueryInformationToken(
                         Status = STATUS_BUFFER_TOO_SMALL;
                     }
 
-                    if (ReturnLength != NULL)
-                    {
-                        *ReturnLength = RequiredLength;
-                    }
+                    *ReturnLength = RequiredLength;
                 }
                 _SEH2_EXCEPT(EXCEPTION_EXECUTE_HANDLER)
                 {
@@ -969,10 +940,7 @@ NtQueryInformationToken(
                         Status = STATUS_BUFFER_TOO_SMALL;
                     }
 
-                    if (ReturnLength != NULL)
-                    {
-                        *ReturnLength = RequiredLength;
-                    }
+                    *ReturnLength = RequiredLength;
                 }
                 _SEH2_EXCEPT(EXCEPTION_EXECUTE_HANDLER)
                 {
@@ -1018,11 +986,7 @@ NtQueryInformationToken(
                     {
                         /* Buffer size was already verified, no need to check here again
*/
                         *(PULONG)TokenInformation = SessionId;
-
-                        if (ReturnLength != NULL)
-                        {
-                            *ReturnLength = sizeof(ULONG);
-                        }
+                        *ReturnLength = RequiredLength;
                     }
                     _SEH2_EXCEPT(EXCEPTION_EXECUTE_HANDLER)
                     {