fixed curl_easy_duphandle() to properly clean up all memory if any memory

function fails and it returns NULL

1 files changed, 84 insertions, 57 deletions

diff --git a/lib/easy.c b/lib/easy.c
index 85a8abf12..5c3062712 100644
--- a/lib/easy.c
+++ b/lib/easy.c
@@ -420,74 +420,101 @@ CURLcode curl_easy_getinfo(CURL *curl, CURLINFO info, ...)
  */
 CURL *curl_easy_duphandle(CURL *incurl)
 {
+  bool fail = TRUE;
   struct SessionHandle *data=(struct SessionHandle *)incurl;
 
   struct SessionHandle *outcurl = (struct SessionHandle *)
-    malloc(sizeof(struct SessionHandle));
+    calloc(sizeof(struct SessionHandle), 1);
 
   if(NULL == outcurl)
     return NULL; /* failure */
 
-  /* start with clearing the entire new struct */
-  memset(outcurl, 0, sizeof(struct SessionHandle));
+  do {
 
-#ifdef USE_ARES
-  /* If we use ares, we need to setup a new ares channel for the new handle */
-  if(ARES_SUCCESS != ares_init(&outcurl->state.areschannel)) {
-    free(outcurl);
-    return NULL;
-  }
-#endif
-
-  /*
-   * We setup a few buffers we need. We should probably make them
-   * get setup on-demand in the code, as that would probably decrease
-   * the likeliness of us forgetting to init a buffer here in the future.
-   */
-  outcurl->state.headerbuff=(char*)malloc(HEADERSIZE);
-  if(!outcurl->state.headerbuff) {
-    free(outcurl); /* free the memory again */
-    return NULL;
-  }
-  outcurl->state.headersize=HEADERSIZE;
+    /*
+     * We setup a few buffers we need. We should probably make them
+     * get setup on-demand in the code, as that would probably decrease
+     * the likeliness of us forgetting to init a buffer here in the future.
+     */
+    outcurl->state.headerbuff=(char*)malloc(HEADERSIZE);
+    if(!outcurl->state.headerbuff) {
+      break;
+    }
+    outcurl->state.headersize=HEADERSIZE;
 
-  /* copy all userdefined values */
-  outcurl->set = data->set;
-  outcurl->state.numconnects = data->state.numconnects;
-  outcurl->state.connects = (struct connectdata **)
+    /* copy all userdefined values */
+    outcurl->set = data->set;
+    outcurl->state.numconnects = data->state.numconnects;
+    outcurl->state.connects = (struct connectdata **)
       malloc(sizeof(struct connectdata *) * outcurl->state.numconnects);
 
-  if(!outcurl->state.connects) {
-    free(outcurl->state.headerbuff);
-    free(outcurl);
-    return NULL;
-  }
-  memset(outcurl->state.connects, 0,
-         sizeof(struct connectdata *)*outcurl->state.numconnects);
-
-  outcurl->progress.flags    = data->progress.flags;
-  outcurl->progress.callback = data->progress.callback;
-
-  if(data->cookies)
-    /* If cookies are enabled in the parent handle, we enable them
-       in the clone as well! */
-    outcurl->cookies = Curl_cookie_init(data,
-                                        data->cookies->filename,
-                                        outcurl->cookies,
-                                        data->set.cookiesession);
-
-  /* duplicate all values in 'change' */
-  if(data->change.url) {
-    outcurl->change.url = strdup(data->change.url);
-    outcurl->change.url_alloc = TRUE;
-  }
-  if(data->change.proxy) {
-    outcurl->change.proxy = strdup(data->change.proxy);
-    outcurl->change.proxy_alloc = TRUE;
-  }
-  if(data->change.referer) {
-    outcurl->change.referer = strdup(data->change.referer);
-    outcurl->change.referer_alloc = TRUE;
+    if(!outcurl->state.connects) {
+      break;
+    }
+
+    memset(outcurl->state.connects, 0,
+           sizeof(struct connectdata *)*outcurl->state.numconnects);
+
+    outcurl->progress.flags    = data->progress.flags;
+    outcurl->progress.callback = data->progress.callback;
+
+    if(data->cookies) {
+      /* If cookies are enabled in the parent handle, we enable them
+         in the clone as well! */
+      outcurl->cookies = Curl_cookie_init(data,
+                                            data->cookies->filename,
+                                            outcurl->cookies,
+                                            data->set.cookiesession);
+      if(!outcurl->cookies) {
+        break;
+      }
+    }
+
+    /* duplicate all values in 'change' */
+    if(data->change.url) {
+      outcurl->change.url = strdup(data->change.url);
+      if(!outcurl->change.url)
+        break;
+      outcurl->change.url_alloc = TRUE;
+    }
+    if(data->change.proxy) {
+      outcurl->change.proxy = strdup(data->change.proxy);
+      if(!outcurl->change.proxy)
+        break;
+      outcurl->change.proxy_alloc = TRUE;
+    }
+    if(data->change.referer) {
+      outcurl->change.referer = strdup(data->change.referer);
+      if(!outcurl->change.referer)
+        break;
+      outcurl->change.referer_alloc = TRUE;
+    }
+
+#ifdef USE_ARES
+    /* If we use ares, we setup a new ares channel for the new handle */
+    if(ARES_SUCCESS != ares_init(&outcurl->state.areschannel))
+      break;
+#endif
+
+    fail = FALSE; /* we reach this point and thus we are OK */
+
+  } while(0);
+
+  if(fail) {
+    if(outcurl) {
+      if(outcurl->state.connects)
+        free(outcurl->state.connects);
+      if(outcurl->state.headerbuff)
+        free(outcurl->state.headerbuff);
+      if(outcurl->change.proxy)
+        free(outcurl->change.proxy);
+      if(outcurl->change.url)
+        free(outcurl->change.url);
+      if(outcurl->change.referer)
+        free(outcurl->change.referer);
+      free(outcurl); /* free the memory again */
+      outcurl = NULL;
+    }
   }
 
   return outcurl;