Bug 994524 - [Follow up of bug 989135] Fix ssid buffer may overflow.

dom/system/gonk/NetworkUtils.cpp

@@ -75,7 +75,6 @@ static const char* USB_CONFIG_DELIMIT = ",";
 static const char* NETD_MESSAGE_DELIMIT = " ";
 
 static const uint32_t BUF_SIZE = 1024;
-static const uint32_t MAX_SSID_SIZE = 33;
 
 static uint32_t SDK_VERSION;
 
@@ -267,28 +266,6 @@ static void split(char* str, const char* sep, nsTArray<nsString>& result)
   }
 }
 
-/**
- * Helper function to do string search and replace.
- */
-static void replace(const char* src,
-                    const char* strold,
-                    const char* strnew,
-                    char* dst)
-{
-  const char *p, *q;
-  char *r;
-  uint32_t oldlen = strlen(strold);
-  uint32_t newlen = strlen(strnew);
-
-  for (p = src, r = dst; (q = strstr(p, strold)) != nullptr; p = q + oldlen) {
-    strncpy(r, p, q - p);
-    r +=  q - p;
-    strncpy(r, strnew, newlen);
-    r += newlen;
-  }
-  strcpy(r, p);
-}
-
 /**
  * Helper function that implement join function.
  */
@@ -540,31 +517,31 @@ void NetworkUtils::setAccessPoint(CommandChain* aChain,
                                   NetworkResultOptions& aResult)
 {
   char command[MAX_COMMAND_SIZE];
-  char ssid[MAX_SSID_SIZE];
-  char key[MAX_COMMAND_SIZE];
+  nsCString ssid(GET_CHAR(mSsid));
+  nsCString key(GET_CHAR(mKey));
 
-  escapeQuote(GET_CHAR(mSsid), ssid);
-  escapeQuote(GET_CHAR(mKey), key);
+  escapeQuote(ssid);
+  escapeQuote(key);
 
   if (SDK_VERSION >= 19) {
     snprintf(command, MAX_COMMAND_SIZE - 1, "softap set %s \"%s\" broadcast 6 %s \"%s\"",
                      GET_CHAR(mIfname),
-                     ssid,
+                     ssid.get(),
                      GET_CHAR(mSecurity),
-                     key);
+                     key.get());
   } else if (SDK_VERSION >= 16) {
     snprintf(command, MAX_COMMAND_SIZE - 1, "softap set %s \"%s\" %s \"%s\"",
                      GET_CHAR(mIfname),
-                     ssid,
+                     ssid.get(),
                      GET_CHAR(mSecurity),
-                     key);
+                     key.get());
   } else {
     snprintf(command, MAX_COMMAND_SIZE - 1, "softap set %s %s \"%s\" %s \"%s\" 6 0 8",
                      GET_CHAR(mIfname),
                      GET_CHAR(mWifictrlinterfacename),
-                     ssid,
+                     ssid.get(),
                      GET_CHAR(mSecurity),
-                     key);
+                     key.get());
   }
 
   doCommand(command, aChain, aCallback);
@@ -1570,10 +1547,10 @@ bool NetworkUtils::setUSBTethering(NetworkParams& aOptions)
   return true;
 }
 
-void NetworkUtils::escapeQuote(const char* src, char* dst)
+void NetworkUtils::escapeQuote(nsCString& aString)
 {
-  replace(src, "\\", "\\\\", dst);
-  replace(src, "\"", "\\\"", dst);
+  aString.ReplaceSubstring("\\", "\\\\");
+  aString.ReplaceSubstring("\"", "\\\"");
 }
 
 void NetworkUtils::checkUsbRndisState(NetworkParams& aOptions)

dom/system/gonk/NetworkUtils.h

@@ -375,7 +375,7 @@ private:
   void checkUsbRndisState(NetworkParams& aOptions);
   void dumpParams(NetworkParams& aOptions, const char* aType);
 
-  static void escapeQuote(const char* src, char* dst);
+  static void escapeQuote(nsCString& aString);
   inline uint32_t netdResponseType(uint32_t code);
   inline bool isBroadcastMessage(uint32_t code);
   inline bool isError(uint32_t code);