RFR(xs): 8155574: ClassLoader::initialize_module_loader_map crashes if the char_buf is not NULL terminated

[Calvin Cheung]

Hi Ioi,

Thanks for your review.

webrev updated: http://cr.openjdk.java.net/~ccheung/8155574/webrev.01/

Testing in progress.

thanks,
Calvin

On 5/6/16, 4:14 AM, Ioi Lam wrote:
> Hi Calvin,
>
>     char* char_buf = (char*)buffer;
> -   int buflen = (int)strlen(char_buf);
>     char* begin_ptr = char_buf;
>     char* end_ptr = strchr(begin_ptr, '\n');
>
> The strchr() function also expects the buffer to be NUL terminated. So 
> you might have problem later
>
>  985     end_ptr = strchr(begin_ptr, '\n'); <<<<< HERE
>  986   }
>
> It will be must safer if you allocate an extra byte, and explicitly 
> set it to zero:
>
>  char* buffer = NEW_RESOURCE_ARRAY(char, size+1);
>  buffer[size] = '\0';
>
> Thanks
> - Ioi
>
>
>
> On 5/5/16 11:20 AM, Calvin Cheung wrote:
>>
>> Please review this small change for fixing char_buf may not be NULL 
>> terminated.
>> Instead of finding the length of char_buf by using strlen(), this fix 
>> uses the size returned from JImageFindResource().
>>
>> bug: https://bugs.openjdk.java.net/browse/JDK-8155574
>> webrev: http://cr.openjdk.java.net/~ccheung/8155574/webrev.00/
>>
>> Testing:
>>     JPRT
>>     RBT on hotspot_runtime
>>
>> thanks,
>> Calvin
>