authkeys: Avoid double free

If any code after the first fclose(f) in Key::Parse() throws
an exception, the exception handler will unconditionally
call fclose(f) again.

Fix this by setting f to NULL after the first fclose, and
checking the value of f against NULL in the excepton handler.

Signed-off-by: Wolfgang Wallner <[email protected]>

Author: br-ww

common/src/authkeys.cpp

@@ -170,6 +170,7 @@ void Key::Parse(const std::string& filename, bool isSecret0)
             LOG_ERROR("Unsupported key file - %s\n           Supported key formats: AMD Format & OpenSSL format", basefile.c_str());
         }
         fclose(f);
+        f = NULL;
 
         if(errCode != 0)
         {
@@ -195,7 +196,10 @@ void Key::Parse(const std::string& filename, bool isSecret0)
     }
     catch(...) 
     {
-        fclose(f);
+        if (f!=NULL)
+        {
+            fclose(f);
+        }
         throw;
     }
 }