On Mon, Jan 27, 2020 at 12:44:01PM +0100, Pavel Hrdina wrote:
On Thu, Jan 23, 2020 at 11:42:59AM +0000, Daniel P. Berrangé wrote:
The mgetgroups function is a GNULIB custom wrapper around getgrouplist(). This implements a simplified version of that code directly.
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com> --- src/internal.h | 4 ++++ src/util/virutil.c | 34 ++++++++++++++++++++++++++++------ 2 files changed, 32 insertions(+), 6 deletions(-)
diff --git a/src/util/virutil.c b/src/util/virutil.c index 87ca16c088..4bc0aef35f 100644 --- a/src/util/virutil.c +++ b/src/util/virutil.c @@ -1000,11 +1004,27 @@ virGetGroupList(uid_t uid, gid_t gid, gid_t **list) /* invalid users have no supplementary groups */ if (uid != (uid_t)-1 && virGetUserEnt(uid, &user, &primary, NULL, NULL, true) >= 0) { - if ((ret = mgetgroups(user, primary, list)) < 0) { - virReportSystemError(errno, - _("cannot get group list for '%s'"), user); - ret = -1; - goto cleanup; + int nallocgrps = 10; + gid_t *grps = g_new(gid_t, nallocgrps);
This is never used anywhere except in the while loop.
The loop relies on the "grps" pointer being persistent across loop iterations though.
+ while (1) { + int nprevallocgrps = nallocgrps; + int rv; + + rv = getgrouplist(user, primary, grps, &nallocgrps); + + /* Some systems (like Darwin) have a bug where they + never increase max_n_groups. */ + if (rv < 0 && nprevallocgrps == nallocgrps) + nallocgrps *= 2; + + /* either shrinks to actual size, or enlarges tonew size */
s/tonew/to new/
+ grps = g_renew(gid_t, grps, nallocgrps); + + if (rv >= 0) { + ret = rv; + break;
Based on the GNULIB implementation here we should set *list = grps.
Yes.
With that fixed:
Reviewed-by: Pavel Hrdina <phrdina@redhat.com>
Regards, Daniel -- |: https://berrange.com -o- https://www.flickr.com/photos/dberrange :| |: https://libvirt.org -o- https://fstop138.berrange.com :| |: https://entangle-photo.org -o- https://www.instagram.com/dberrange :|