Tomas Janousek wrote:
> Hello,
>
> On Fri, Oct 26, 2007 at 04:50:02PM +0200, Simon Matter wrote:
>>>>> --- auth_unix.c.~1.46.~ 2007-09-27 16:02:45.000000000 -0400
>>>>> +++ auth_unix.c 2007-10-25 23:02:15.000000000 -0400
>>>>> @@ -225,7 +225,7 @@
>>>>> struct group *grp;
>>>>> #ifdef HAVE_GETGROUPLIST
>>>>> gid_t gid, *groupids = NULL;
>>>>> - int ret, ngroups = 0;
>>>>> + int ret, ngroups = 10;
>>>>> #else
>>>>> char **mem;
>>>>> #endif
>>>>> @@ -248,10 +248,7 @@
>>>>> #ifdef HAVE_GETGROUPLIST
>>>>> gid = pwd ? pwd->pw_gid : (gid_t) -1;
>>>>>
>>>>> - /* get number of groups user is member of into ngroups */
>>>>> - getgrouplist(identifier, gid, NULL, &ngroups);
>>>>> -
>>>>> - /* get the actual group ids */
>>>>> + /* get the group ids */
>>>>> do {
>>>>> groupids = (gid_t *)xrealloc((gid_t *)groupids,
>>>>> ngroups * sizeof(gid_t));
>
> This should not change behaviour nor cause additional problems, I think.
>
> The gnu manpage of getgrouplist does not mention the NULL case either, though
> it works. If it segfaults, I'd consider that a libc failure, since when
> ngroups == 0, the pointer shouldn't be used at all (it should point to the
> first element of the array but array of 0 elements has no first element).
>
> If it really is a wrong code of mine, then sorry for not testing on anything
> other than Linux.
Its not a problem. Since we might have to realloc() the grouplist
anyways, it really doesn't make much sense to just get the count first.
--
Kenneth Murchison
Systems Programmer
Project Cyrus Developer/Maintainer
Carnegie Mellon University
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