fixed a problem with getgroups() where it could include our current

effective gid which could mean that the user gets group 0 in their
group list for acl interpretation

this is a replacement fix for the one richard did in 2.2 (which didn't
cope wiith variable behaviour depending on which nss module was in
use)
(This used to be commit cfc5ca3416cea5ea5d2ac34f5521cb6367e42cd2)

1 files changed, 36 insertions, 0 deletions

diff --git a/source3/lib/util_sec.c b/source3/lib/util_sec.c
index d59b1b0471..132748ce13 100644
--- a/source3/lib/util_sec.c
+++ b/source3/lib/util_sec.c
@@ -227,6 +227,7 @@ void set_effective_gid(gid_t gid)
 }
 
 static uid_t saved_euid, saved_ruid;
+static gid_t saved_egid, saved_rgid;
 
 /****************************************************************************
  save the real and effective uid for later restoration. Used by the quotas
@@ -264,6 +265,41 @@ void restore_re_uid(void)
 	assert_uid(saved_ruid, saved_euid);
 }
 
+
+/****************************************************************************
+ save the real and effective gid for later restoration. Used by the 
+ getgroups code
+****************************************************************************/
+void save_re_gid(void)
+{
+	saved_rgid = getgid();
+	saved_egid = getegid();
+}
+
+/****************************************************************************
+ and restore them!
+****************************************************************************/
+void restore_re_gid(void)
+{
+#if USE_SETRESUID
+	setresgid(saved_rgid, saved_egid, -1);
+#elif USE_SETREUID
+	setregid(saved_rgid, -1);
+	setregid(-1,saved_egid);
+#elif USE_SETUIDX
+	setgidx(ID_REAL, saved_rgid);
+	setgidx(ID_EFFECTIVE, saved_egid);
+#else
+	set_effective_gid(saved_egid);
+	if (getgid() != saved_rgid)
+		setgid(saved_rgid);
+	set_effective_gid(saved_egid);
+#endif
+
+	assert_gid(saved_rgid, saved_egid);
+}
+
+
 /****************************************************************************
  set the real AND effective uid to the current effective uid in a way that
  allows root to be regained.