Hi Samuel,
I tested the attached diff and it seems to work.
Your example now has groups 1,2,3 and also sshd works when nscd is enabled.
I am not sure about the extreme cases of n == 0 and if n +1 overflows. Also if
n is really big there might be problems with the VLA.
Is setgroups the only libc function that has the problem?
Y.
diff --git a/sysdeps/mach/hurd/setgroups.c b/sysdeps/mach/hurd/setgroups.c
index e5a5d59f9c..bcebe10cf5 100644
--- a/sysdeps/mach/hurd/setgroups.c
+++ b/sysdeps/mach/hurd/setgroups.c
@@ -17,6 +17,7 @@
#include <errno.h>
#include <sys/types.h>
+#include <unistd.h>
#include <grp.h>
#include <hurd.h>
#include <hurd/id.h>
@@ -27,12 +28,20 @@ setgroups (size_t n, const gid_t *groups)
{
error_t err;
auth_t newauth;
- size_t i;
- gid_t new[n];
+ size_t i, start;
+ gid_t egid;
+ gid_t new[n + 1];
+ start = 0;
+ egid = getegid ();
+ if (egid != (gid_t) -1 && n > 0 && egid != groups[0])
+ {
+ new[0] = egid;
+ start = 1;
+ }
/* Fault before taking locks. */
for (i = 0; i < n; ++i)
- new[i] = groups[i];
+ new[i + start] = groups[i];
retry:
HURD_CRITICAL_BEGIN;
@@ -45,7 +54,7 @@ retry:
__auth_makeauth (port, NULL, MACH_MSG_TYPE_COPY_SEND, 0,
_hurd_id.gen.uids, _hurd_id.gen.nuids,
_hurd_id.aux.uids, _hurd_id.aux.nuids,
- new, n,
+ new, n + start,
_hurd_id.aux.gids, _hurd_id.aux.ngids,
&newauth));
}
