[ntdll] Care about empty fields of assembly_identity structure in actctx.c

[Roman Mindalev]

On parsing of manifest in PE module is possible access to zero address
and crash. It's happens because not all manifest attributes can be
specified and pointers in assembly_identity structure can be
uninitialized. This patch adds function for setting empty strings in
structure elements when they not initialized.
---
 dlls/ntdll/actctx.c |   42 ++++++++++++++++++++++++++++++++++++++++++
 1 files changed, 42 insertions(+), 0 deletions(-)

diff --git a/dlls/ntdll/actctx.c b/dlls/ntdll/actctx.c
index 79d475f..7ce5bad 100644
--- a/dlls/ntdll/actctx.c
+++ b/dlls/ntdll/actctx.c
@@ -332,12 +332,51 @@ static struct dll_redirect* add_dll_redirect(struct assembly* assembly)
     return &assembly->dlls[assembly->num_dlls++];
 }
 
+static void initialize_assembly_identity(struct assembly_identity *ai)
+{
+  ai->name = NULL;
+  ai->arch = NULL;
+  ai->public_key = NULL;
+  ai->language = NULL;
+  ai->type = NULL;
+}
+
+static void malloc_emptystrs_assembly_identity(struct assembly_identity *ai)
+{
+  if (ai->name == NULL)
+  {
+    ai->name = RtlAllocateHeap( GetProcessHeap(), 0, sizeof(WCHAR) );
+    ai->name[0] = 0;
+  }
+  if (ai->arch == NULL)
+  {
+    ai->arch = RtlAllocateHeap( GetProcessHeap(), 0, sizeof(WCHAR) );
+    ai->arch[0] = 0;
+  }
+  if (ai->public_key == NULL)
+  {
+    ai->public_key = RtlAllocateHeap( GetProcessHeap(), 0, sizeof(WCHAR) );
+    ai->public_key[0] = 0;
+  }
+  if (ai->language == NULL)
+  {
+    ai->language = RtlAllocateHeap( GetProcessHeap(), 0, sizeof(WCHAR) );
+    ai->language[0] = 0;
+  }
+  if (ai->type == NULL)
+  {
+    ai->type = RtlAllocateHeap( GetProcessHeap(), 0, sizeof(WCHAR) );
+    ai->type[0] = 0;
+  }
+}
+
 static void free_assembly_identity(struct assembly_identity *ai)
 {
     RtlFreeHeap( GetProcessHeap(), 0, ai->name );
     RtlFreeHeap( GetProcessHeap(), 0, ai->arch );
     RtlFreeHeap( GetProcessHeap(), 0, ai->public_key );
     RtlFreeHeap( GetProcessHeap(), 0, ai->language );
+    RtlFreeHeap( GetProcessHeap(), 0, ai->type );
 }
 
 static struct entity* add_entity(struct entity_array *array, DWORD kind)
@@ -1168,6 +1207,8 @@ static BOOL parse_dependent_assembly_elem(xmlbuf_t* xmlbuf, struct actctx_loader
     xmlstr_t                    elem;
     BOOL                        end = FALSE, ret = TRUE;
 
+    initialize_assembly_identity(&ai);
+
     if (!parse_expect_no_attr(xmlbuf, &end) || end) return end;
 
     memset(&ai, 0, sizeof(ai));
@@ -1945,6 +1986,7 @@ static NTSTATUS lookup_assembly(struct actctx_loader* acl,
     UNICODE_STRING nameW;
     HANDLE file;
 
+    malloc_emptystrs_assembly_identity(ai);
     TRACE( "looking for name=%s version=%s arch=%s\n",
            debugstr_w(ai->name), debugstr_version(&ai->version), debugstr_w(ai->arch) );
 
-- 
1.6.2


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