[PATCH xserver] xkb: Initialize pad bytes sent in replies of geometry requests.

[Rami Ylimäki]

On 03/16/2011 02:43 AM, Peter Hutterer wrote:
>
>> -    memcpy(&wire[2],str,len);
>> -    wire+= ((2+len+3)/4)*4;
>> +    paddedLen= pad_to_int32(sizeof(len)+len)-sizeof(len);
>> +    strncpy(&wire[sizeof(len)],str,paddedLen);
>> +    wire+= sizeof(len)+paddedLen;

> looking at this again, does this really fix the issue?

Yes, I have verified it with Valgrind.

> assuming a string of strlen 11, paddedLen is 14.
> strncpy will copy 12 bytes (strlen + \0), so you write 14 bytes in total but
> advance wire by 16 bytes. the last 2 are uninitialized.

Not true, strncpy with n=14 copies always exactly 14 bytes. If n exceeds 
the size of source string, destination string is padded with null 
characters. Note that strncpy was used instead of strcpy.

-- Rami