[weiden] 20455: protect access to buffers with SEH in NtSetSecurityObject and NtQuerySecurityObject and ask for the proper access rights

protect access to buffers with SEH in NtSetSecurityObject and
NtQuerySecurityObject and ask for the proper access rights
Modified: trunk/reactos/ntoskrnl/include/internal/se.h
Modified: trunk/reactos/ntoskrnl/ob/security.c
Modified: trunk/reactos/ntoskrnl/se/semgr.c
  _____  

Modified: trunk/reactos/ntoskrnl/include/internal/se.h
--- trunk/reactos/ntoskrnl/include/internal/se.h	2005-12-30
01:39:34 UTC (rev 20454)
+++ trunk/reactos/ntoskrnl/include/internal/se.h	2005-12-30
01:41:02 UTC (rev 20455)
@@ -274,6 +274,14 @@

     KeLeaveCriticalRegion();
\
   while(0)
 
+VOID STDCALL
+SeQuerySecurityAccessMask(IN SECURITY_INFORMATION SecurityInformation,
+                          OUT PACCESS_MASK DesiredAccess);
+
+VOID STDCALL
+SeSetSecurityAccessMask(IN SECURITY_INFORMATION SecurityInformation,
+                        OUT PACCESS_MASK DesiredAccess);
+
 #endif /* __NTOSKRNL_INCLUDE_INTERNAL_SE_H */
 
 /* EOF */
  _____  

Modified: trunk/reactos/ntoskrnl/ob/security.c
--- trunk/reactos/ntoskrnl/ob/security.c	2005-12-30 01:39:34 UTC
(rev 20454)
+++ trunk/reactos/ntoskrnl/ob/security.c	2005-12-30 01:41:02 UTC
(rev 20455)
@@ -159,47 +159,74 @@

 		      IN ULONG Length,
 		      OUT PULONG ResultLength)
 {
-  POBJECT_HEADER Header;
-  PVOID Object;
-  NTSTATUS Status;
+    KPROCESSOR_MODE PreviousMode;
+    PVOID Object;
+    POBJECT_HEADER Header;
+    ACCESS_MASK DesiredAccess = (ACCESS_MASK)0;
+    NTSTATUS Status = STATUS_SUCCESS;
 
-  PAGED_CODE();
+    PAGED_CODE();
 
-  DPRINT("NtQuerySecurityObject() called\n");
+    PreviousMode = ExGetPreviousMode();
 
-  Status = ObReferenceObjectByHandle(Handle,
-				     (SecurityInformation &
SACL_SECURITY_INFORMATION) ? ACCESS_SYSTEM_SECURITY : 0,
-				     NULL,
-				     KeGetPreviousMode(),
-				     &Object,
-				     NULL);
-  if (!NT_SUCCESS(Status))
+    if (PreviousMode != KernelMode)
     {
-      DPRINT1("ObReferenceObjectByHandle() failed (Status %lx)\n",
Status);
-      return Status;
+        _SEH_TRY
+        {
+            ProbeForWrite(SecurityDescriptor,
+                          Length,
+                          sizeof(ULONG));
+            ProbeForWriteUlong(ResultLength);
+        }
+        _SEH_HANDLE
+        {
+            Status = _SEH_GetExceptionCode();
+        }
+        _SEH_END;
+
+        if (!NT_SUCCESS(Status)) return Status;
     }
 
-  Header = BODY_TO_HEADER(Object);
-  if (Header->Type == NULL)
+    /* get the required access rights for the operation */
+    SeQuerySecurityAccessMask(SecurityInformation,
+                              &DesiredAccess);
+
+    Status = ObReferenceObjectByHandle(Handle,
+                                       DesiredAccess,
+                                       NULL,
+                                       PreviousMode,
+                                       &Object,
+                                       NULL);
+
+    if (NT_SUCCESS(Status))
     {
-      DPRINT1("Invalid object type\n");
-      ObDereferenceObject(Object);
-      return STATUS_UNSUCCESSFUL;
-    }
+        Header = BODY_TO_HEADER(Object);
+        ASSERT(Header->Type != NULL);
 
-      *ResultLength = Length;
-      Status = Header->Type->TypeInfo.SecurityProcedure(Object,
-					    QuerySecurityDescriptor,
-					    SecurityInformation,
-					    SecurityDescriptor,
-					    ResultLength,
-                        NULL,
-                        NonPagedPool,
-                        NULL);
+        Status = Header->Type->TypeInfo.SecurityProcedure(Object,
+
QuerySecurityDescriptor,
+
SecurityInformation,
+
SecurityDescriptor,
+                                                          &Length,
+
&Header->SecurityDescriptor,
+
Header->Type->TypeInfo.PoolType,
+
&Header->Type->TypeInfo.GenericMapping);
 
-  ObDereferenceObject(Object);
+        ObDereferenceObject(Object);
 
-  return Status;
+        /* return the required length */
+        _SEH_TRY
+        {
+            *ResultLength = Length;
+        }
+        _SEH_HANDLE
+        {
+            Status = _SEH_GetExceptionCode();
+        }
+        _SEH_END;
+    }
+
+    return Status;
 }
 
 
@@ -211,46 +238,81 @@
 		    IN SECURITY_INFORMATION SecurityInformation,
 		    IN PSECURITY_DESCRIPTOR SecurityDescriptor)
 {
-  POBJECT_HEADER Header;
-  PVOID Object;
-  NTSTATUS Status;
+    KPROCESSOR_MODE PreviousMode;
+    PVOID Object;
+    POBJECT_HEADER Header;
+    SECURITY_DESCRIPTOR_RELATIVE *CapturedSecurityDescriptor;
+    ACCESS_MASK DesiredAccess = (ACCESS_MASK)0;
+    NTSTATUS Status;
 
-  PAGED_CODE();
+    PAGED_CODE();
 
-  DPRINT("NtSetSecurityObject() called\n");
+    /* make sure the caller doesn't pass a NULL security descriptor! */
+    if (SecurityDescriptor == NULL)
+    {
+        return STATUS_ACCESS_DENIED;
+    }
 
-  Status = ObReferenceObjectByHandle(Handle,
-				     (SecurityInformation &
SACL_SECURITY_INFORMATION) ? ACCESS_SYSTEM_SECURITY : 0,
-				     NULL,
-				     KeGetPreviousMode(),
-				     &Object,
-				     NULL);
-  if (!NT_SUCCESS(Status))
+    PreviousMode = ExGetPreviousMode();
+
+    /* capture and make a copy of the security descriptor */
+    Status = SeCaptureSecurityDescriptor(SecurityDescriptor,
+                                         PreviousMode,
+                                         PagedPool,
+                                         TRUE,
+
(PSECURITY_DESCRIPTOR*)&CapturedSecurityDescriptor);
+    if (!NT_SUCCESS(Status))
     {
-      DPRINT1("ObReferenceObjectByHandle() failed (Status %lx)\n",
Status);
-      return Status;
+        DPRINT1("Capturing the security descriptor failed! Status:
0x%lx\n", Status);
+        return Status;
     }
 
-  Header = BODY_TO_HEADER(Object);
-  if (Header->Type == NULL)
+    /* make sure the security descriptor passed by the caller
+       is valid for the operation we're about to perform */
+    if (((SecurityInformation & OWNER_SECURITY_INFORMATION) &&
+         (CapturedSecurityDescriptor->Owner == 0)) ||
+        ((SecurityInformation & GROUP_SECURITY_INFORMATION) &&
+         (CapturedSecurityDescriptor->Group == 0)))
     {
-      DPRINT1("Invalid object type\n");
-      ObDereferenceObject(Object);
-      return STATUS_UNSUCCESSFUL;
+        Status = STATUS_INVALID_SECURITY_DESCR;
     }
+    else
+    {
+        /* get the required access rights for the operation */
+        SeSetSecurityAccessMask(SecurityInformation,
+                                &DesiredAccess);
 
-      Status = Header->Type->TypeInfo.SecurityProcedure(Object,
-					    SetSecurityDescriptor,
-					    SecurityInformation,
-					    SecurityDescriptor,
-					    NULL,
-                        NULL,
-                        NonPagedPool,
-                        NULL);
+        Status = ObReferenceObjectByHandle(Handle,
+                                           DesiredAccess,
+                                           NULL,
+                                           PreviousMode,
+                                           &Object,
+                                           NULL);
 
-  ObDereferenceObject(Object);
+        if (NT_SUCCESS(Status))
+        {
+            Header = BODY_TO_HEADER(Object);
+            ASSERT(Header->Type != NULL);
 
-  return Status;
+            Status = Header->Type->TypeInfo.SecurityProcedure(Object,
+
SetSecurityDescriptor,
+
SecurityInformation,
+
(PSECURITY_DESCRIPTOR)SecurityDescriptor,
+                                                              NULL,
+
&Header->SecurityDescriptor,
+
Header->Type->TypeInfo.PoolType,
+
&Header->Type->TypeInfo.GenericMapping);
+
+            ObDereferenceObject(Object);
+        }
+    }
+
+    /* release the descriptor */
+
SeReleaseSecurityDescriptor((PSECURITY_DESCRIPTOR)CapturedSecurityDescri
ptor,
+                                PreviousMode,
+                                TRUE);
+
+    return Status;
 }
 
 
  _____  

Modified: trunk/reactos/ntoskrnl/se/semgr.c
--- trunk/reactos/ntoskrnl/se/semgr.c	2005-12-30 01:39:34 UTC (rev
20454)
+++ trunk/reactos/ntoskrnl/se/semgr.c	2005-12-30 01:41:02 UTC (rev
20455)
@@ -1037,7 +1037,7 @@

 	      OUT PACCESS_MASK GrantedAccess,
 	      OUT PNTSTATUS AccessStatus)
 {
-  SECURITY_SUBJECT_CONTEXT SubjectSecurityContext;
+  SECURITY_SUBJECT_CONTEXT SubjectSecurityContext = {0};
   KPROCESSOR_MODE PreviousMode;
   PTOKEN Token;
   NTSTATUS Status;
@@ -1082,8 +1082,6 @@
       return STATUS_ACCESS_VIOLATION;
     }
 
-  RtlZeroMemory(&SubjectSecurityContext,
-		sizeof(SECURITY_SUBJECT_CONTEXT));
   SubjectSecurityContext.ClientToken = Token;
   SubjectSecurityContext.ImpersonationLevel =
Token->ImpersonationLevel;
 
@@ -1118,4 +1116,37 @@
   return Status;
 }
 
+VOID STDCALL
+SeQuerySecurityAccessMask(IN SECURITY_INFORMATION SecurityInformation,
+                          OUT PACCESS_MASK DesiredAccess)
+{
+    if (SecurityInformation & (OWNER_SECURITY_INFORMATION |
+                               GROUP_SECURITY_INFORMATION |
DACL_SECURITY_INFORMATION))
+    {
+        *DesiredAccess |= READ_CONTROL;
+    }
+    if (SecurityInformation & SACL_SECURITY_INFORMATION)
+    {
+        *DesiredAccess |= ACCESS_SYSTEM_SECURITY;
+    }
+}
+
+VOID STDCALL
+SeSetSecurityAccessMask(IN SECURITY_INFORMATION SecurityInformation,
+                        OUT PACCESS_MASK DesiredAccess)
+{
+    if (SecurityInformation & (OWNER_SECURITY_INFORMATION |
GROUP_SECURITY_INFORMATION))
+    {
+        *DesiredAccess |= WRITE_OWNER;
+    }
+    if (SecurityInformation & DACL_SECURITY_INFORMATION)
+    {
+        *DesiredAccess |= WRITE_DAC;
+    }
+    if (SecurityInformation & SACL_SECURITY_INFORMATION)
+    {
+        *DesiredAccess |= ACCESS_SYSTEM_SECURITY;
+    }
+}
+
 /* EOF */