Re: [ECOS] Bug in getifaddrs() - allocation of buffer

[Gary Thomas <gary at mlbassoc dot com>]

On Tue, 2003-09-16 at 10:37, Andrew Lunn wrote:
> On Tue, Sep 16, 2003 at 08:18:11AM -0700, Jay Foster wrote:
> > The function getifaddrs() in file packages/net/common/current/src/ifaddrs.c
> > has a couple of bugs in it.
> > 
> > On lines 151 and 157, it calls "free(buf)", but "buf" is a local buffer
> > allocated on the stack.  These should either be removed, or change the 
> > allocation of "buf" to be malloced.  These free() calls seem to indicate
> > that at one time, the "buf" buffer was malloced, which makes sense, since
> > it is a 1K byte buffer.  This seems a bit large for an auto stack variable.
> 
> I agree, it should be malloc'd. Its been broken since at least
> 20-May-02!
> 

Actually, it's been broken (in this respect) forever :-(  This is how 
the code looked when originally imported.

> > 
> > On lines 172 through 177 (CYGPKG_NET_INET6), it returns from the function
> > (error case), but does not free the malloced buffer "data".  Need to add
> > a call to "free(data);" here.  Also, if the "buf" buffer allocation is 
> > changed to be malloced, instead of on the stack, then add a "free(buf);"
> > here too.
> 
> Agreed.

Yes, a little looking at this file and how those pointers [objects] are
allocated and freed would be a good idea.

-- 
Gary Thomas <gary@mlbassoc.com>
MLB Associates


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