From d536bd7f6635a46e2b24ada4383cad842b76343d Mon Sep 17 00:00:00 2001
From: "Enrico Weigelt, metux IT consult" <info@metux.net>
Date: Tue, 25 Mar 2025 15:25:55 +0100
Subject: [PATCH] dix: AddExtension: simplify error return path

Signed-off-by: Enrico Weigelt, metux IT consult <info@metux.net>
---
 dix/extension.c | 37 +++++++++++++++++++------------------
 dix/privates.c  |  3 +++
 2 files changed, 22 insertions(+), 18 deletions(-)

diff --git a/dix/extension.c b/dix/extension.c
index 8e1a0f479..fa64429e3 100644
--- a/dix/extension.c
+++ b/dix/extension.c
@@ -76,7 +76,6 @@ AddExtension(const char *name, int NumEvents, int NumErrors,
              unsigned short (*MinorOpcodeProc) (ClientPtr c3))
 {
     int i;
-    ExtensionEntry *ext, **newexts;
 
     if (!MainProc || !SwappedMainProc || !MinorOpcodeProc)
         return ((ExtensionEntry *) NULL);
@@ -87,27 +86,21 @@ AddExtension(const char *name, int NumEvents, int NumErrors,
         return ((ExtensionEntry *) NULL);
     }
 
-    ext = calloc(1, sizeof(ExtensionEntry));
+    ExtensionEntry *ext = calloc(1, sizeof(ExtensionEntry));
     if (!ext)
         return NULL;
-    if (!dixAllocatePrivates(&ext->devPrivates, PRIVATE_EXTENSION)) {
-        free(ext);
-        return NULL;
-    }
+    if (!dixAllocatePrivates(&ext->devPrivates, PRIVATE_EXTENSION))
+        goto badalloc;
     ext->name = strdup(name);
-    if (!ext->name) {
-        dixFreePrivates(ext->devPrivates, PRIVATE_EXTENSION);
-        free(ext);
-        return ((ExtensionEntry *) NULL);
-    }
+    if (!ext->name)
+        goto badalloc;
+
     i = NumExtensions;
-    newexts = reallocarray(extensions, i + 1, sizeof(ExtensionEntry *));
-    if (!newexts) {
-        free((void *) ext->name);
-        dixFreePrivates(ext->devPrivates, PRIVATE_EXTENSION);
-        free(ext);
-        return ((ExtensionEntry *) NULL);
-    }
+
+    ExtensionEntry **newexts = reallocarray(extensions, i + 1, sizeof(ExtensionEntry *));
+    if (!newexts)
+        goto badalloc;
+
     NumExtensions++;
     extensions = newexts;
     extensions[i] = ext;
@@ -140,6 +133,14 @@ AddExtension(const char *name, int NumEvents, int NumErrors,
     RegisterExtensionNames(ext);
 #endif
     return ext;
+
+badalloc:
+    if (ext) {
+        free((char*)ext->name);
+        dixFreePrivates(ext->devPrivates, PRIVATE_EXTENSION);
+        free(ext);
+    }
+    return NULL;
 }
 
 /*
diff --git a/dix/privates.c b/dix/privates.c
index 72cda714f..96533a217 100644
--- a/dix/privates.c
+++ b/dix/privates.c
@@ -541,6 +541,9 @@ _dixFreeObjectWithPrivates(void *object, PrivatePtr privates,
 void
 dixFreePrivates(PrivatePtr privates, DevPrivateType type)
 {
+    if (!privates)
+        return;
+
     _dixFiniPrivates(privates, type);
     --global_keys[type].allocated;
     free(privates);