4 files changed, 13 insertions, 5 deletions
diff --git a/source3/winbindd/wb_fill_pwent.c b/source3/winbindd/wb_fill_pwent.c
index a716245ce8..62b1b4a189 100644
--- a/source3/winbindd/wb_fill_pwent.c
+++ b/source3/winbindd/wb_fill_pwent.c
@@ -111,7 +111,10 @@ static void wb_fill_pwent_sid2gid_done(struct tevent_req *subreq)
 	/* Username */
 
 	fstrcpy(user_name, state->info->acct_name);
-	strlower_m(user_name);
+	if (!strlower_m(user_name)) {
+		tevent_req_nterror(req, NT_STATUS_INVALID_PARAMETER);
+		return;
+	}
 	status = normalize_name_map(state, domain, user_name, &mapped_name);
 
 	/* Basic removal of whitespace */
diff --git a/source3/winbindd/winbindd_cache.c b/source3/winbindd/winbindd_cache.c
index cfa843424a..2c9dd4a9b3 100644
--- a/source3/winbindd/winbindd_cache.c
+++ b/source3/winbindd/winbindd_cache.c
@@ -1868,7 +1868,7 @@ static NTSTATUS name_to_sid(struct winbindd_domain *domain,
 			if (!strupper_m(discard_const_p(char, domain_name))) {
 				return NT_STATUS_INVALID_PARAMETER;
 			}
-			strlower_m(discard_const_p(char, name));
+			(void)strlower_m(discard_const_p(char, name));
 			wcache_save_sid_to_name(domain, status, sid, domain_name, name, *type);
 		}
 	}
diff --git a/source3/winbindd/winbindd_pam.c b/source3/winbindd/winbindd_pam.c
index 48bb79bdcd..d8febe6a5c 100644
--- a/source3/winbindd/winbindd_pam.c
+++ b/source3/winbindd/winbindd_pam.c
@@ -217,7 +217,9 @@ static NTSTATUS append_afs_token(TALLOC_CTX *mem_ctx,
 		return NT_STATUS_NO_MEMORY;
 	}
 
-	strlower_m(afsname);
+	if (!strlower_m(afsname)) {
+		return NT_STATUS_INVALID_PARAMETER;
+	}
 
 	DEBUG(10, ("Generating token for user %s\n", afsname));
 
diff --git a/source3/winbindd/winbindd_util.c b/source3/winbindd/winbindd_util.c
index 656735633b..c36ae0bb0a 100644
--- a/source3/winbindd/winbindd_util.c
+++ b/source3/winbindd/winbindd_util.c
@@ -931,7 +931,7 @@ void fill_domain_username(fstring name, const char *domain, const char *user, bo
 	fstring tmp_user;
 
 	fstrcpy(tmp_user, user);
-	strlower_m(tmp_user);
+	(void)strlower_m(tmp_user);
 
 	if (can_assume && assume_domain(domain)) {
 		strlcpy(name, tmp_user, sizeof(fstring));
@@ -954,7 +954,10 @@ char *fill_domain_username_talloc(TALLOC_CTX *mem_ctx,
 	char *tmp_user, *name;
 
 	tmp_user = talloc_strdup(mem_ctx, user);
-	strlower_m(tmp_user);
+	if (!strlower_m(tmp_user)) {
+		TALLOC_FREE(tmp_user);
+		return NULL;
+	}
 
 	if (can_assume && assume_domain(domain)) {
 		name = tmp_user;