With smbd 3.0.23 the access to shares protected by a valid users constraint is denied if the permission is grant to a unix group.

E.g. if I have a share with "valid users = @users" (or something similar) nobody can access this share. If I enter the user names directly, everything is fine.

The problem seems to have something to do with gid mapping.
I fixed it by this dirty patch:

Index: passdb/lookup_sid.c
===================================================================
--- passdb/lookup_sid.c (revision 15311)
+++ passdb/lookup_sid.c (working copy)
@@ -1070,11 +1070,12 @@
                goto done;
        }

+       /* GID-BUG???
        if (pdb_rid_algorithm() && (gid < max_algorithmic_gid())) {
                sid_copy(psid, get_global_sam_sid());
                sid_append_rid(psid, pdb_gid_to_group_rid(gid));
                goto done;
-       } else {
+       } else */ {
                sid_copy(psid, &global_sid_Unix_Groups);
                sid_append_rid(psid, gid);
                goto done;

However, it is unlikely that I hit the nail on the head.

Environment:
I use the LANMAN2 protocol (OS/2 clients) and a Linux server. But as far as I remember I had the same problem using the NTLM protocol.

Marcel