Re: devlib2 bugfix (rare string corruption)

[Michael Davidsaver <mdavidsaver@bnl.gov>]

Committed.

http://epics.hg.sourceforge.net/hgweb/epics/devlib2/rev/542a4744b240


On 12/19/2012 12:59 PM, Till Straumann wrote:
> vallocPrintf()
>
> first calls vsnprintf() with a length argument of zero to determine
> the necessary buffer size, allocates a buffer and then calls
>
> size2 = vsprintf(buf,format,args)
>
> It then goes on and complains if size2 is different from what the
> initial vsnprintf() returned.
>
> If, however, this really happens (and I have observed this under 
> 64-bit ubuntu-12.10)
> then it is well possible that vsprintf() writes beyond the length of 
> the buffer.
>
> Hence, I suggest to replace vsprintf() by
>
> size2 = vsnprintf(buf, size+1, format, args)
>
> just to make sure. (Note that the 'size' argument to snprintf() 
> includes space for
> the terminating NUL whereas the return value does not.)
>
> - Till
>
> A patch is attached for sake of convenience.