ksmbd: add supplementary group support

Signed-off-by: Namjae Jeon <[email protected]>

ksmbd_netlink.h

@@ -143,6 +143,8 @@ struct ksmbd_login_response {
 	__u16	hash_sz;			/* hash size */
 	__s8	hash[KSMBD_REQ_MAX_HASH_SZ];	/* password hash */
 	__u32	reserved[16];			/* Reserved room */
+	__u32	ngroup;
+	__u32	gid[];
 };
 
 /*

smb_common.c

@@ -785,6 +785,7 @@ int __ksmbd_override_fsids(struct ksmbd_work *work,
 	struct group_info *gi;
 	unsigned int uid;
 	unsigned int gid;
+	int i;
 
 	uid = user_uid(sess->user);
 	gid = user_gid(sess->user);
@@ -800,11 +801,25 @@ int __ksmbd_override_fsids(struct ksmbd_work *work,
 	cred->fsuid = make_kuid(&init_user_ns, uid);
 	cred->fsgid = make_kgid(&init_user_ns, gid);
 
-	gi = groups_alloc(0);
+	gi = groups_alloc(share->ngroups);
 	if (!gi) {
 		abort_creds(cred);
 		return -ENOMEM;
 	}
+
+	if (share->ngroups <= NGROUPS_MAX) {
+		for (i = 0; i < share->ngroups; i++) {
+			if (gid_eq(GLOBAL_ROOT_GID,
+				   make_kgid(&init_user_ns, share->gid[i])))
+				gi->gid[i] = cred->fsgid;
+			else
+				gi->gid[i] = make_kgid(&init_user_ns,
+					       	share->gid[i]);
+		}
+
+		groups_sort(gi);
+	}
+
 	set_groups(cred, gi);
 	put_group_info(gi);