Check error returns from strupper_m() (in all reasonable places).

49 files changed, 283 insertions, 89 deletions

diff --git a/libgpo/gpext/gpext.c b/libgpo/gpext/gpext.c
index 8bda729d692..df84475754d 100644
--- a/libgpo/gpext/gpext.c
+++ b/libgpo/gpext/gpext.c
@@ -440,7 +440,9 @@ static WERROR gp_extension_store_reg_entry(TALLOC_CTX *mem_ctx,
 	subkeyname = GUID_string2(mem_ctx, &entry->guid);
 	W_ERROR_HAVE_NO_MEMORY(subkeyname);
 
-	strupper_m(discard_const_p(char, subkeyname));
+	if (!strupper_m(discard_const_p(char, subkeyname))) {
+		return WERR_INVALID_PARAM;
+	}
 
 	werr = gp_store_reg_subkey(mem_ctx,
 				   subkeyname,
diff --git a/source3/auth/auth_builtin.c b/source3/auth/auth_builtin.c
index b757894a7c6..d61a0ec7bf0 100644
--- a/source3/auth/auth_builtin.c
+++ b/source3/auth/auth_builtin.c
@@ -97,7 +97,9 @@ static NTSTATUS check_name_to_ntstatus_security(const struct auth_context *auth_
 	fstrcpy(user, user_info->client.account_name);
 
 	if (strnequal("NT_STATUS", user, strlen("NT_STATUS"))) {
-		strupper_m(user);
+		if (!strupper_m(user)) {
+			return NT_STATUS_INVALID_PARAMETER;
+		}
 		return nt_status_string_to_code(user);
 	}
 
diff --git a/source3/lib/charcnv.c b/source3/lib/charcnv.c
index 5863d72f380..32ba97aaa4d 100644
--- a/source3/lib/charcnv.c
+++ b/source3/lib/charcnv.c
@@ -61,7 +61,10 @@ size_t push_ascii(void *dest, const char *src, size_t dest_len, int flags)
 		if (!tmpbuf) {
 			smb_panic("malloc fail");
 		}
-		strupper_m(tmpbuf);
+		if (!strupper_m(tmpbuf)) {
+			SAFE_FREE(tmpbuf);
+			return (size_t)-1;
+		}
 		src = tmpbuf;
 	}
 
diff --git a/source3/lib/username.c b/source3/lib/username.c
index 51920043655..7435a59ac7a 100644
--- a/source3/lib/username.c
+++ b/source3/lib/username.c
@@ -128,7 +128,10 @@ static struct passwd *Get_Pwnam_internals(TALLOC_CTX *mem_ctx,
 	}
 
 	/* Try as uppercase, if username wasn't originally uppercase */
-	strupper_m(user2);
+	if (!strupper_m(user2)) {
+		goto done;
+	}
+
 	if(strcmp(user, user2) != 0) {
 		DEBUG(5,("Trying _Get_Pwnam(), username as uppercase is %s\n",
 			 user2));
diff --git a/source3/lib/util_names.c b/source3/lib/util_names.c
index 0e128eab1cd..cf54a0eecee 100644
--- a/source3/lib/util_names.c
+++ b/source3/lib/util_names.c
@@ -63,8 +63,7 @@ static bool set_my_netbios_names(const char *name, int i)
 	smb_my_netbios_names[i] = SMB_STRDUP(name);
 	if (!smb_my_netbios_names[i])
 		return False;
-	strupper_m(smb_my_netbios_names[i]);
-	return True;
+	return strupper_m(smb_my_netbios_names[i]);
 }
 
 /***********************************************************************
diff --git a/source3/lib/util_str.c b/source3/lib/util_str.c
index f97cd3cc25e..b740de6659a 100644
--- a/source3/lib/util_str.c
+++ b/source3/lib/util_str.c
@@ -58,7 +58,7 @@ bool strnequal(const char *s1,const char *s2,size_t n)
 void strnorm(char *s, int case_default)
 {
 	if (case_default == CASE_UPPER)
-		strupper_m(s);
+		(void)strupper_m(s); /* FIXME - return a bool here. */
 	else
 		strlower_m(s);
 }
@@ -575,7 +575,6 @@ bool strupper_m(char *s)
 	/* Catch mb conversion errors that may not terminate. */
 	if (errno) {
 		s[len-1] = '\0';
-		ret = false;
 	}
 	errno = errno_save;
 	return ret;
@@ -989,7 +988,11 @@ int asprintf_strupper_m(char **strp, const char *fmt, ...)
 	if (ret == -1)
 		return -1;
 
-	strupper_m(result);
+	if (!strupper_m(result)) {
+		SAFE_FREE(result);
+		return -1;
+	}
+
 	*strp = result;
 	return ret;
 }
@@ -1006,7 +1009,10 @@ char *talloc_asprintf_strupper_m(TALLOC_CTX *t, const char *fmt, ...)
 	if (ret == NULL) {
 		return NULL;
 	}
-	strupper_m(ret);
+	if (!strupper_m(ret)) {
+		TALLOC_FREE(ret);
+		return NULL;
+	}
 	return ret;
 }
 
diff --git a/source3/libads/kerberos.c b/source3/libads/kerberos.c
index 7e953800114..80f99de4823 100644
--- a/source3/libads/kerberos.c
+++ b/source3/libads/kerberos.c
@@ -861,7 +861,9 @@ bool create_local_private_krb5_conf_for_domain(const char *realm,
 		fname, realm, domain ));
 
 	realm_upper = talloc_strdup(fname, realm);
-	strupper_m(realm_upper);
+	if (!strupper_m(realm_upper)) {
+		goto done;
+	}
 
 	kdc_ip_string = get_kdc_ip_string(dname, realm, sitename, pss, kdc_name);
 	if (!kdc_ip_string) {
diff --git a/source3/libads/kerberos_keytab.c b/source3/libads/kerberos_keytab.c
index 0e23a6add39..eb2603b6720 100644
--- a/source3/libads/kerberos_keytab.c
+++ b/source3/libads/kerberos_keytab.c
@@ -564,7 +564,10 @@ int ads_keytab_create_default(ADS_STRUCT *ads)
 
 	/* upper case the sAMAccountName to make it easier for apps to
 	   know what case to use in the keytab file */
-	strupper_m(sam_account_name);
+	if (!strupper_m(sam_account_name)) {
+		ret = -1;
+		goto done;
+	}
 
 	ret = ads_keytab_add_entry(ads, sam_account_name);
 	if (ret != 0) {
diff --git a/source3/libads/ldap.c b/source3/libads/ldap.c
index 640a020a8bd..fa88244598b 100644
--- a/source3/libads/ldap.c
+++ b/source3/libads/ldap.c
@@ -298,7 +298,11 @@ static bool ads_try_connect(ADS_STRUCT *ads, const char *server, bool gc)
 	ads->config.flags	       = cldap_reply.server_type;
 	ads->config.ldap_server_name   = SMB_STRDUP(cldap_reply.pdc_dns_name);
 	ads->config.realm              = SMB_STRDUP(cldap_reply.dns_domain);
-	strupper_m(ads->config.realm);
+	if (!strupper_m(ads->config.realm)) {
+		ret = false;
+		goto out;
+	}
+
 	ads->config.bind_path          = ads_build_dn(ads->config.realm);
 	if (*cldap_reply.server_site) {
 		ads->config.server_site_name =
@@ -1945,7 +1949,11 @@ ADS_STATUS ads_add_service_principal_name(ADS_STRUCT *ads, const char *machine_n
 		ads_msgfree(ads, res);
 		return ADS_ERROR(LDAP_NO_MEMORY);
 	}
-	strupper_m(psp1);
+	if (!strupper_m(psp1)) {
+		ret = ADS_ERROR(LDAP_NO_MEMORY);
+		goto out;
+	}
+
 	strlower_m(&psp1[strlen(spn)]);
 	servicePrincipalName[0] = psp1;
 
@@ -1959,7 +1967,11 @@ ADS_STATUS ads_add_service_principal_name(ADS_STRUCT *ads, const char *machine_n
 		ret = ADS_ERROR(LDAP_NO_MEMORY);
 		goto out;
 	}
-	strupper_m(psp2);
+	if (!strupper_m(psp2)) {
+		ret = ADS_ERROR(LDAP_NO_MEMORY);
+		goto out;
+	}
+
 	strlower_m(&psp2[strlen(spn)]);
 	servicePrincipalName[1] = psp2;
 
diff --git a/source3/libads/sasl.c b/source3/libads/sasl.c
index ee3a693f717..a04ac9dd691 100644
--- a/source3/libads/sasl.c
+++ b/source3/libads/sasl.c
@@ -653,7 +653,12 @@ static ADS_STATUS ads_guess_service_principal(ADS_STRUCT *ads,
 		}
 
 		strlower_m(server);
-		strupper_m(server_realm);
+		if (!strupper_m(server_realm)) {
+			SAFE_FREE(server);
+			SAFE_FREE(server_realm);
+			return ADS_ERROR(LDAP_NO_MEMORY);
+		}
+
 		if (asprintf(&princ, "ldap/%s@%s", server, server_realm) == -1) {
 			SAFE_FREE(server);
 			SAFE_FREE(server_realm);
@@ -679,7 +684,11 @@ static ADS_STATUS ads_guess_service_principal(ADS_STRUCT *ads,
 		}
 
 		strlower_m(server);
-		strupper_m(server_realm);
+		if (!strupper_m(server_realm)) {
+			SAFE_FREE(server);
+			SAFE_FREE(server_realm);
+			return ADS_ERROR(LDAP_NO_MEMORY);
+		}
 		if (asprintf(&princ, "ldap/%s@%s", server, server_realm) == -1) {
 			SAFE_FREE(server);
 			SAFE_FREE(server_realm);
diff --git a/source3/libnet/libnet_join.c b/source3/libnet/libnet_join.c
index 399c13a86a7..5806f7bc75c 100644
--- a/source3/libnet/libnet_join.c
+++ b/source3/libnet/libnet_join.c
@@ -136,7 +136,10 @@ static ADS_STATUS libnet_connect_ads(const char *dns_domain_name,
 			*cp++ = '\0';
 			SAFE_FREE(my_ads->auth.realm);
 			my_ads->auth.realm = smb_xstrdup(cp);
-			strupper_m(my_ads->auth.realm);
+			if (!strupper_m(my_ads->auth.realm)) {
+				ads_destroy(&my_ads);
+				return ADS_ERROR_LDAP(LDAP_NO_MEMORY);
+			}
 		}
 	}
 
@@ -381,7 +384,9 @@ static ADS_STATUS libnet_join_set_machine_spn(TALLOC_CTX *mem_ctx,
 	if (!spn) {
 		return ADS_ERROR_LDAP(LDAP_NO_MEMORY);
 	}
-	strupper_m(spn);
+	if (!strupper_m(spn)) {
+		return ADS_ERROR_LDAP(LDAP_NO_MEMORY);
+	}
 	spn_array[0] = spn;
 
 	if (!name_to_fqdn(my_fqdn, r->in.machine_name)
diff --git a/source3/libsmb/cliconnect.c b/source3/libsmb/cliconnect.c
index cd914bf8529..b74faa6fd9c 100644
--- a/source3/libsmb/cliconnect.c
+++ b/source3/libsmb/cliconnect.c
@@ -2048,7 +2048,9 @@ NTSTATUS cli_session_setup(struct cli_state *cli,
 	    (p=strchr_m(user2,*lp_winbind_separator()))) {
 		*p = 0;
 		user = p+1;
-		strupper_m(user2);
+		if (!strupper_m(user2)) {
+			return NT_STATUS_INVALID_PARAMETER;
+		}
 		workgroup = user2;
 	}
 
diff --git a/source3/libsmb/clirap.c b/source3/libsmb/clirap.c
index 6685fbd1d8b..7c185ef5ad0 100644
--- a/source3/libsmb/clirap.c
+++ b/source3/libsmb/clirap.c
@@ -117,13 +117,17 @@ bool cli_NetWkstaUserLogon(struct cli_state *cli,char *user, char *workstation)
 	SSVAL(p,0,1);
 	p += 2;
 	strlcpy(p,user,sizeof(param)-PTR_DIFF(p,param));
-	strupper_m(p);
+	if (!strupper_m(p)) {
+		return false;
+	}
 	p += 21;
 	p++;
 	p += 15;
 	p++;
 	strlcpy(p, workstation,sizeof(param)-PTR_DIFF(p,param));
-	strupper_m(p);
+	if (!strupper_m(p)) {
+		return false;
+	}
 	p += 16;
 	SSVAL(p, 0, CLI_BUFFER_SIZE);
 	p += 2;
diff --git a/source3/libsmb/clirap2.c b/source3/libsmb/clirap2.c
index 1333f468f47..05d8fb2a291 100644
--- a/source3/libsmb/clirap2.c
+++ b/source3/libsmb/clirap2.c
@@ -1876,12 +1876,16 @@ bool cli_NetWkstaUserLogoff(struct cli_state *cli, const char *user, const char
 	PUTDWORD(p, 0); /* Null pointer */
 	PUTDWORD(p, 0); /* Null pointer */
 	strlcpy(upperbuf, user, sizeof(upperbuf));
-	strupper_m(upperbuf);
+	if (!strupper_m(upperbuf)) {
+		return false;
+	}
 	tmp = upperbuf;
 	PUTSTRINGF(p, tmp, RAP_USERNAME_LEN);
 	p++; /* strange format, but ok */
 	strlcpy(upperbuf, workstation, sizeof(upperbuf));
-	strupper_m(upperbuf);
+	if (!strupper_m(upperbuf)) {
+		return false;
+	}
 	tmp = upperbuf;
 	PUTSTRINGF(p, tmp, RAP_MACHNAME_LEN);
 	PUTWORD(p, CLI_BUFFER_SIZE);
diff --git a/source3/libsmb/namequery_dc.c b/source3/libsmb/namequery_dc.c
index f4c2fc1929b..df5eeb8d89a 100644
--- a/source3/libsmb/namequery_dc.c
+++ b/source3/libsmb/namequery_dc.c
@@ -137,7 +137,10 @@ static bool ads_dc_name(const char *domain,
 	SAFE_FREE(sitename);
 
 	fstrcpy(srv_name, ads->config.ldap_server_name);
-	strupper_m(srv_name);
+	if (!strupper_m(srv_name)) {
+		ads_destroy(&ads);
+		return false;
+	}
 #ifdef HAVE_ADS
 	*dc_ss = ads->ldap.ss;
 #else
diff --git a/source3/libsmb/nmblib.c b/source3/libsmb/nmblib.c
index 767ff81476e..a6816db5b95 100644
--- a/source3/libsmb/nmblib.c
+++ b/source3/libsmb/nmblib.c
@@ -933,7 +933,7 @@ void make_nmb_name( struct nmb_name *n, const char *name, int type)
 	fstring unix_name;
 	memset( (char *)n, '\0', sizeof(struct nmb_name) );
 	fstrcpy(unix_name, name);
-	strupper_m(unix_name);
+	(void)strupper_m(unix_name);
 	push_ascii(n->name, unix_name, sizeof(n->name), STR_TERMINATE);
 	n->name_type = (unsigned int)type & 0xFF;
 	push_ascii(n->scope,  lp_netbios_scope(), 64, STR_TERMINATE);
@@ -1277,7 +1277,9 @@ char *name_mangle(TALLOC_CTX *mem_ctx, const char *In, char name_type)
 		nstring buf_dos;
 
 		pull_ascii_fstring(buf_unix, In);
-		strupper_m(buf_unix);
+		if (!strupper_m(buf_unix)) {
+			return NULL;
+		}
 
 		push_ascii_nstring(buf_dos, buf_unix);
 		put_name(buf, buf_dos, ' ', name_type);
diff --git a/source3/modules/vfs_streams_depot.c b/source3/modules/vfs_streams_depot.c
index f984f75e9f2..a3ce8c1cc5b 100644
--- a/source3/modules/vfs_streams_depot.c
+++ b/source3/modules/vfs_streams_depot.c
@@ -345,7 +345,10 @@ static NTSTATUS stream_smb_fname(vfs_handle_struct *handle,
 		}
 	} else {
 		/* Normalize the stream type to upercase. */
-		strupper_m(strrchr_m(stream_fname, ':') + 1);
+		if (!strupper_m(strrchr_m(stream_fname, ':') + 1)) {
+			status = NT_STATUS_INVALID_PARAMETER;
+			goto fail;
+		}
 	}
 
 	DEBUG(10, ("stream filename = %s\n", stream_fname));
diff --git a/source3/modules/vfs_streams_xattr.c b/source3/modules/vfs_streams_xattr.c
index 291531e59aa..dd1135d77cc 100644
--- a/source3/modules/vfs_streams_xattr.c
+++ b/source3/modules/vfs_streams_xattr.c
@@ -119,7 +119,9 @@ static NTSTATUS streams_xattr_get_name(TALLOC_CTX *ctx,
 		}
 	} else {
 		/* Normalize the stream type to upercase. */
-		strupper_m(strrchr_m(*xattr_name, ':') + 1);
+		if (!strupper_m(strrchr_m(*xattr_name, ':') + 1)) {
+			return NT_STATUS_INVALID_PARAMETER;
+		}
 	}
 
 	DEBUG(10, ("xattr_name: %s, stream_name: %s\n", *xattr_name,
diff --git a/source3/nmbd/nmbd_browserdb.c b/source3/nmbd/nmbd_browserdb.c
index b7c99005bbf..bd027239eca 100644
--- a/source3/nmbd/nmbd_browserdb.c
+++ b/source3/nmbd/nmbd_browserdb.c
@@ -109,8 +109,14 @@ struct browse_cache_record *create_browser_in_lmb_cache( const char *work_name,
 
 	unstrcpy( browc->lmb_name, browser_name);
 	unstrcpy( browc->work_group, work_name);
-	strupper_m( browc->lmb_name );
-	strupper_m( browc->work_group );
+	if (!strupper_m( browc->lmb_name )) {
+		SAFE_FREE(browc);
+		return NULL;
+	}
+	if (!strupper_m( browc->work_group )) {
+		SAFE_FREE(browc);
+		return NULL;
+	}
   
 	browc->ip = ip;
  
diff --git a/source3/nmbd/nmbd_browsesync.c b/source3/nmbd/nmbd_browsesync.c
index e009cf9a614..b56baedf270 100644
--- a/source3/nmbd/nmbd_browsesync.c
+++ b/source3/nmbd/nmbd_browsesync.c
@@ -120,7 +120,10 @@ static void announce_local_master_browser_to_domain_master_browser( struct work_
 	p++;
 
 	unstrcpy(myname, lp_netbios_name());
-	strupper_m(myname);
+	if (!strupper_m(myname)) {
+		DEBUG(2,("strupper_m %s failed\n", myname));
+		return;
+	}
 	myname[15]='\0';
 	/* The call below does CH_UNIX -> CH_DOS conversion. JRA */
 	push_ascii(p, myname, sizeof(outbuf)-PTR_DIFF(p,outbuf)-1, STR_TERMINATE);
diff --git a/source3/nmbd/nmbd_elections.c b/source3/nmbd/nmbd_elections.c
index ac0d8735120..1947e37e3af 100644
--- a/source3/nmbd/nmbd_elections.c
+++ b/source3/nmbd/nmbd_elections.c
@@ -51,7 +51,10 @@ static void send_election_dgram(struct subnet_record *subrec, const char *workgr
 	SIVAL(p,5,timeup*1000); /* ms - Despite what the spec says. */
 	p += 13;
 	unstrcpy(srv_name, server_name);
-	strupper_m(srv_name);
+	if (!strupper_m(srv_name)) {
+		DEBUG(2,("strupper_m failed for %s\n", srv_name));
+		return;
+	}
 	/* The following call does UNIX -> DOS charset conversion. */
 	push_ascii(p, srv_name, sizeof(outbuf)-PTR_DIFF(p,outbuf)-1, STR_TERMINATE);
 	p = skip_string(outbuf,sizeof(outbuf),p);
diff --git a/source3/nmbd/nmbd_incomingdgrams.c b/source3/nmbd/nmbd_incomingdgrams.c
index 582848c1fcf..153a86db555 100644
--- a/source3/nmbd/nmbd_incomingdgrams.c
+++ b/source3/nmbd/nmbd_incomingdgrams.c
@@ -572,7 +572,10 @@ static void send_backup_list_response(struct subnet_record *subrec,
 	/* We always return at least one name - our own. */
 	count = 1;
 	unstrcpy(myname, lp_netbios_name());
-	strupper_m(myname);
+	if (!strupper_m(myname)) {
+		DEBUG(4,("strupper_m %s failed\n", myname));
+		return;
+	}
 	myname[15]='\0';
 	push_ascii(p, myname, sizeof(outbuf)-PTR_DIFF(p,outbuf)-1, STR_TERMINATE);
 
diff --git a/source3/nmbd/nmbd_incomingrequests.c b/source3/nmbd/nmbd_incomingrequests.c
index b2545f102fc..562c388ee29 100644
--- a/source3/nmbd/nmbd_incomingrequests.c
+++ b/source3/nmbd/nmbd_incomingrequests.c
@@ -347,7 +347,10 @@ subnet %s - name not found.\n", nmb_namestr(&nmb->question.question_name),
 			unstring name;
 
 			pull_ascii_nstring(name, sizeof(name), namerec->name.name);
-			strupper_m(name);
+			if (!strupper_m(name)) {
+				DEBUG(2,("strupper_m %s failed\n", name));
+				return;
+			}
 			if (!strequal(name,"*") &&
 					!strequal(name,"__SAMBA__") &&
 					(name_type < 0x1b || name_type >= 0x20 || 
diff --git a/source3/nmbd/nmbd_namelistdb.c b/source3/nmbd/nmbd_namelistdb.c
index 61c1d784f78..c06bddafbdd 100644
--- a/source3/nmbd/nmbd_namelistdb.c
+++ b/source3/nmbd/nmbd_namelistdb.c
@@ -44,7 +44,7 @@ void set_samba_nb_type(void)
  Convert a NetBIOS name to upper case.
 ***************************************************************************/
 
-static void upcase_name( struct nmb_name *target, const struct nmb_name *source )
+static bool upcase_name( struct nmb_name *target, const struct nmb_name *source )
 {
 	int i;
 	unstring targ;
@@ -55,11 +55,15 @@ static void upcase_name( struct nmb_name *target, const struct nmb_name *source
 	}
 
 	pull_ascii_nstring(targ, sizeof(targ), target->name);
-	strupper_m( targ );
+	if (!strupper_m( targ )) {
+		return false;
+	}
 	push_ascii_nstring( target->name, targ);
 
 	pull_ascii(scope, target->scope, 64, -1, STR_TERMINATE);
-	strupper_m( scope );
+	if (!strupper_m( scope )) {
+		return false;
+	}
 	push_ascii(target->scope, scope, 64, STR_TERMINATE);
 
 	/* fudge... We're using a byte-by-byte compare, so we must be sure that
@@ -72,6 +76,7 @@ static void upcase_name( struct nmb_name *target, const struct nmb_name *source
 	for( i = strlen( target->scope ); i < sizeof( target->scope ); i++ ) {
 		target->scope[i] = '\0';
 	}
+	return true;
 }
 
 /**************************************************************************
@@ -104,7 +109,9 @@ struct name_record *find_name_on_subnet(struct subnet_record *subrec,
 	struct nmb_name uc_name;
 	struct name_record *name_ret;
 
-	upcase_name( &uc_name, nmbname );
+	if (!upcase_name( &uc_name, nmbname )) {
+		return NULL;
+	}
 	
 	if (subrec == wins_server_subnet) {
 		return find_name_on_wins_subnet(&uc_name, self_only);
@@ -216,7 +223,11 @@ bool add_name_to_subnet( struct subnet_record *subrec,
 	namerec->subnet = subrec;
 
 	make_nmb_name(&namerec->name, name, type);
-	upcase_name(&namerec->name, NULL );
+	if (!upcase_name(&namerec->name, NULL )) {
+		SAFE_FREE(namerec->data.ip);
+		SAFE_FREE(namerec);
+		return False;
+	}
 
 	/* Enter the name as active. */
 	namerec->data.nb_flags = nb_flags | NB_ACTIVE;
diff --git a/source3/nmbd/nmbd_sendannounce.c b/source3/nmbd/nmbd_sendannounce.c
index 97bab9d25a7..86012b834b2 100644
--- a/source3/nmbd/nmbd_sendannounce.c
+++ b/source3/nmbd/nmbd_sendannounce.c
@@ -106,7 +106,10 @@ static void send_announcement(struct subnet_record *subrec, int announce_type,
 	SIVAL(p,1,announce_interval*1000); /* Milliseconds - despite the spec. */
 
 	strlcpy(upper_server_name, server_name ? server_name : "", sizeof(upper_server_name));
-	strupper_m(upper_server_name);
+	if (!strupper_m(upper_server_name)) {
+		DEBUG(2,("strupper_m %s failed\n", upper_server_name));
+		return;
+	}
 	push_string_check(p+5, upper_server_name, 16, STR_ASCII|STR_TERMINATE);
 
 	SCVAL(p,21,SAMBA_MAJOR_NBT_ANNOUNCE_VERSION); /* Major version. */
@@ -568,7 +571,10 @@ for workgroup %s on subnet %s.\n", lp_workgroup(), FIRST_SUBNET->subnet_name ));
 	p++;
 
 	unstrcpy(myname, lp_netbios_name());
-	strupper_m(myname);
+	if (!strupper_m(myname)) {
+		DEBUG(2,("strupper_m %s failed\n", myname));
+		return;
+	}
 	myname[15]='\0';
 	push_ascii(p, myname, sizeof(outbuf)-PTR_DIFF(p,outbuf)-1, STR_TERMINATE);
 
diff --git a/source3/nmbd/nmbd_serverlistdb.c b/source3/nmbd/nmbd_serverlistdb.c
index ac16b5a98c9..05ca6e9367f 100644
--- a/source3/nmbd/nmbd_serverlistdb.c
+++ b/source3/nmbd/nmbd_serverlistdb.c
@@ -119,7 +119,11 @@ workgroup %s. This is a bug.\n", name, work->work_group));
  
 	fstrcpy(servrec->serv.name,name);
 	fstrcpy(servrec->serv.comment,comment);
-	strupper_m(servrec->serv.name);
+	if (!strupper_m(servrec->serv.name)) {
+		DEBUG(2,("strupper_m %s failed\n", servrec->serv.name));
+		SAFE_FREE(servrec);
+		return NULL;
+	}
 	servrec->serv.type  = servertype;
 
 	update_server_ttl(servrec, ttl);
diff --git a/source3/nmbd/nmbd_winsserver.c b/source3/nmbd/nmbd_winsserver.c
index 87b9990a63f..d56d0f8aedd 100644
--- a/source3/nmbd/nmbd_winsserver.c
+++ b/source3/nmbd/nmbd_winsserver.c
@@ -217,7 +217,7 @@ static TDB_DATA name_to_key(const struct nmb_name *nmbname)
 	memset(keydata, '\0', sizeof(keydata));
 
 	pull_ascii_nstring(keydata, sizeof(unstring), nmbname->name);
-	strupper_m(keydata);
+	(void)strupper_m(keydata);
 	keydata[sizeof(unstring)] = nmbname->name_type;
 	key.dptr = (uint8 *)keydata;
 	key.dsize = sizeof(keydata);
diff --git a/source3/passdb/lookup_sid.c b/source3/passdb/lookup_sid.c
index 8e14cec3e81..a2d793feb32 100644
--- a/source3/passdb/lookup_sid.c
+++ b/source3/passdb/lookup_sid.c
@@ -339,7 +339,10 @@ bool lookup_name(TALLOC_CTX *mem_ctx,
 			TALLOC_FREE(tmp_ctx);
 			return false;
 		}
-		strupper_m(tmp_dom);
+		if (!strupper_m(tmp_dom)) {
+			TALLOC_FREE(tmp_ctx);
+			return false;
+		}
 		*ret_domain = tmp_dom;
 	}
 
diff --git a/source3/passdb/machine_account_secrets.c b/source3/passdb/machine_account_secrets.c
index 30f5f822ff9..a4b5709b283 100644
--- a/source3/passdb/machine_account_secrets.c
+++ b/source3/passdb/machine_account_secrets.c
@@ -148,7 +148,9 @@ bool secrets_store_domain_guid(const char *domain, struct GUID *guid)
 #endif
 
 	slprintf(key, sizeof(key)-1, "%s/%s", SECRETS_DOMAIN_GUID, domain);
-	strupper_m(key);
+	if (!strupper_m(key)) {
+		return false;
+	}
 	return secrets_store(key, guid, sizeof(struct GUID));
 }
 
@@ -160,7 +162,9 @@ bool secrets_fetch_domain_guid(const char *domain, struct GUID *guid)
 	struct GUID new_guid;
 
 	slprintf(key, sizeof(key)-1, "%s/%s", SECRETS_DOMAIN_GUID, domain);
-	strupper_m(key);
+	if (!strupper_m(key)) {
+		return false;
+	}
 	dyn_guid = (struct GUID *)secrets_fetch(key, &size);
 
 	if (!dyn_guid) {
diff --git a/source3/registry/reg_backend_db.c b/source3/registry/reg_backend_db.c
index 75ad507e2b0..3e561eb3893 100644
--- a/source3/registry/reg_backend_db.c
+++ b/source3/registry/reg_backend_db.c
@@ -561,7 +561,9 @@ static bool upgrade_v2_to_v3_check_subkeylist(struct db_context *db,
 	};
 	bool success = false;
 	char *path = talloc_asprintf(talloc_tos(), "%s\\%s", key, subkey);
-	strupper_m(path);
+	if (!strupper_m(path)) {
+		goto done;
+	}
 
 	if (!dbwrap_exists(db, string_term_tdb_data(path))) {
 		NTSTATUS status;
diff --git a/source3/registry/reg_util_internal.c b/source3/registry/reg_util_internal.c
index b15015b988d..e256c75cb2d 100644
--- a/source3/registry/reg_util_internal.c
+++ b/source3/registry/reg_util_internal.c
@@ -113,7 +113,10 @@ char *normalize_reg_path(TALLOC_CTX *ctx, const char *keyname )
 		p = strrchr(nkeyname, '\\');
 	}
 
-	strupper_m(nkeyname);
+	if (!strupper_m(nkeyname)) {
+		TALLOC_FREE(nkeyname);
+		return NULL;
+	}
 
 	return nkeyname;
 }
diff --git a/source3/smbd/lanman.c b/source3/smbd/lanman.c
index 1b5de57ad4e..b22619ff356 100644
--- a/source3/smbd/lanman.c
+++ b/source3/smbd/lanman.c
@@ -4004,7 +4004,9 @@ static bool api_NetWkstaGetInfo(struct smbd_server_connection *sconn,
 
 	SIVAL(p,0,PTR_DIFF(p2,*rdata)); /* host name */
 	strlcpy(p2,get_local_machine_name(),PTR_DIFF(endp,p2));
-	strupper_m(p2);
+	if (!strupper_m(p2)) {
+		return false;
+	}
 	p2 = skip_string(*rdata,*rdata_len,p2);
 	if (!p2) {
 		return False;
@@ -4021,7 +4023,9 @@ static bool api_NetWkstaGetInfo(struct smbd_server_connection *sconn,
 
 	SIVAL(p,0,PTR_DIFF(p2,*rdata)); /* login domain */
 	strlcpy(p2,lp_workgroup(),PTR_DIFF(endp,p2));
-	strupper_m(p2);
+	if (!strupper_m(p2)) {
+		return false;
+	}
 	p2 = skip_string(*rdata,*rdata_len,p2);
 	if (!p2) {
 		return False;
@@ -4691,7 +4695,9 @@ static bool api_WWkstaUserLogon(struct smbd_server_connection *sconn,
 			fstring mypath;
 			fstrcpy(mypath,"\\\\");
 			fstrcat(mypath,get_local_machine_name());
-			strupper_m(mypath);
+			if (!strupper_m(mypath)) {
+				return false;
+			}
 			PACKS(&desc,"z",mypath); /* computer */
 		}
 
@@ -5082,7 +5088,7 @@ static void fill_printdest_info(struct spoolss_PrinterInfo2 *info2, int uLevel,
 
 	strncpy(buf, info2->printername, sizeof(buf)-1);
 	buf[sizeof(buf)-1] = 0;
-	strupper_m(buf);
+	(void)strupper_m(buf);
 
 	if (uLevel <= 1) {
 		PACKS(desc,"B9",buf);	/* szName */
diff --git a/source3/smbd/mangle_hash.c b/source3/smbd/mangle_hash.c
index 056879c8765..8a44ea2d6a2 100644
--- a/source3/smbd/mangle_hash.c
+++ b/source3/smbd/mangle_hash.c
@@ -630,7 +630,10 @@ static bool to_8_3(char magic_char, const char *in, char out[13], int default_ca
 	} else
 		csum = str_checksum(s);
 
-	strupper_m( s );
+	if (!strupper_m( s )) {
+		SAFE_FREE(s);
+		return false;
+	}
 
 	if( p ) {
 		if( p == s )
diff --git a/source3/smbd/mangle_hash2.c b/source3/smbd/mangle_hash2.c
index 09cd44d5af3..655c72745a4 100644
--- a/source3/smbd/mangle_hash2.c
+++ b/source3/smbd/mangle_hash2.c
@@ -291,7 +291,7 @@ static unsigned int mangle_hash(const char *key, unsigned int length)
 	length = MIN(length,sizeof(fstring)-1);
 	strncpy(str, key, length);
 	str[length] = 0;
-	strupper_m(str);
+	(void)strupper_m(str);
 
 	/* the length of a multi-byte string can change after a strupper_m */
 	length = strlen(str);
diff --git a/source3/smbd/service.c b/source3/smbd/service.c
index 4fc1aa3e2dd..ce9cff90e24 100644
--- a/source3/smbd/service.c
+++ b/source3/smbd/service.c
@@ -257,7 +257,10 @@ static NTSTATUS share_sanity_checks(const struct tsocket_address *remote_address
 		}
 	}
 
-	strupper_m(dev);
+	if (!strupper_m(dev)) {
+		DEBUG(2,("strupper_m %s failed\n", dev));
+		return NT_STATUS_INVALID_PARAMETER;
+	}
 
 	if (lp_print_ok(snum)) {
 		if (!strequal(dev, "LPT1:")) {
diff --git a/source3/torture/torture.c b/source3/torture/torture.c
index 69e583ad55e..525484719b3 100644
--- a/source3/torture/torture.c
+++ b/source3/torture/torture.c
@@ -8273,7 +8273,7 @@ static NTSTATUS split_ntfs_stream_name(TALLOC_CTX *mem_ctx, const char *fname,
 		/*
 		 * upper-case the type field
 		 */
-		strupper_m(strchr_m(stream, ':')+1);
+		(void)strupper_m(strchr_m(stream, ':')+1);
 	}
 
  done:
diff --git a/source3/utils/net_ads.c b/source3/utils/net_ads.c
index a4f1588e515..b1eac52df2c 100644
--- a/source3/utils/net_ads.c
+++ b/source3/utils/net_ads.c
@@ -287,7 +287,10 @@ retry:
 		*cp++ = '\0';
 		SAFE_FREE(ads->auth.realm);
 		ads->auth.realm = smb_xstrdup(cp);
-		strupper_m(ads->auth.realm);
+		if (!strupper_m(ads->auth.realm)) {
+			ads_destroy(&ads);
+			return ADS_ERROR(LDAP_NO_MEMORY);
+		}
        }
 
 	status = ads_connect(ads);
@@ -1371,7 +1374,10 @@ static void _net_ads_join_dns_updates(TALLOC_CTX *ctx, struct libnet_JoinCtx *r)
 		goto done;
 	}
 
-	strupper_m(ads_dns->auth.realm);
+	if (!strupper_m(ads_dns->auth.realm)) {
+		d_fprintf(stderr, _("strupper_m %s failed\n"), ads_dns->auth.realm);
+		goto done;
+	}
 
 	ret = ads_kinit_password(ads_dns);
 	if (ret != 0) {
diff --git a/source3/utils/net_idmap.c b/source3/utils/net_idmap.c
index f067071de17..ebc14e528de 100644
--- a/source3/utils/net_idmap.c
+++ b/source3/utils/net_idmap.c
@@ -492,7 +492,11 @@ static bool idmap_store_secret(const char *backend,
 
 	if (r < 0) return false;
 
-	strupper_m(tmp); /* make sure the key is case insensitive */
+	/* make sure the key is case insensitive */
+	if (!strupper_m(tmp)) {
+		free(tmp);
+		return false;
+	}
 	ret = secrets_store_generic(tmp, identity, secret);
 
 	free(tmp);
diff --git a/source3/utils/net_registry_check.c b/source3/utils/net_registry_check.c
index 872aa5a3710..45a01f20f5e 100644
--- a/source3/utils/net_registry_check.c
+++ b/source3/utils/net_registry_check.c
@@ -419,7 +419,10 @@ static bool read_info(struct check_ctx *ctx, const char *key, TDB_DATA val)
 static bool is_all_upper(const char *str) {
 	bool ret;
 	char *tmp = talloc_strdup(talloc_tos(), str);
-	strupper_m(tmp);
+	if (!strupper_m(tmp)) {
+		talloc_free(tmp);
+		return false;
+	}
 	ret = (strcmp(tmp, str) == 0);
 	talloc_free(tmp);
 	return ret;
@@ -698,7 +701,10 @@ static bool normalize_path_internal(char* path, char sep) {
 	}
 	*optr = '\0';
 
-	strupper_m(path);
+	if (!strupper_m(path)) {
+		talloc_free(discard_const(orig));
+		return false;
+	}
 	changed = (strcmp(orig, path) != 0);
 	talloc_free(discard_const(orig));
 	return changed;
diff --git a/source3/utils/net_rpc.c b/source3/utils/net_rpc.c
index 46c3c917793..ae5db99dd38 100644
--- a/source3/utils/net_rpc.c
+++ b/source3/utils/net_rpc.c
@@ -4750,7 +4750,11 @@ static bool get_user_tokens(struct net_context *c, int *num_tokens,
 		} else {
 			*p++ = '\0';
 			fstrcpy(domain, users[i]);
-			strupper_m(domain);
+			if (!strupper_m(domain)) {
+				DEBUG(1, ("strupper_m %s failed\n", domain));
+				wbcFreeMemory(users);
+				return false;
+			}
 			fstrcpy(user, p);
 		}
 
@@ -5794,7 +5798,10 @@ static NTSTATUS rpc_trustdom_add_internals(struct net_context *c,
 		return NT_STATUS_NO_MEMORY;
 	}
 
-	strupper_m(acct_name);
+	if (!strupper_m(acct_name)) {
+		SAFE_FREE(acct_name);
+		return NT_STATUS_INVALID_PARAMETER;
+	}
 
 	init_lsa_String(&lsa_acct_name, acct_name);
 
@@ -5978,7 +5985,10 @@ static NTSTATUS rpc_trustdom_del_internals(struct net_context *c,
 	if (acct_name == NULL)
 		return NT_STATUS_NO_MEMORY;
 
-	strupper_m(acct_name);
+	if (!strupper_m(acct_name)) {
+		TALLOC_FREE(acct_name);
+		return NT_STATUS_INVALID_PARAMETER;
+	}
 
 	/* Get samr policy handle */
 	status = dcerpc_samr_Connect2(b, mem_ctx,
@@ -6224,13 +6234,20 @@ static int rpc_trustdom_establish(struct net_context *c, int argc,
 	}
 
 	domain_name = smb_xstrdup(argv[0]);
-	strupper_m(domain_name);
+	if (!strupper_m(domain_name)) {
+		SAFE_FREE(domain_name);
+		return -1;
+	}
 
 	/* account name used at first is our domain's name with '$' */
 	if (asprintf(&acct_name, "%s$", lp_workgroup()) == -1) {
 		return -1;
 	}
-	strupper_m(acct_name);
+	if (!strupper_m(acct_name)) {
+		SAFE_FREE(domain_name);
+		SAFE_FREE(acct_name);
+		return -1;
+	}
 
 	/*
 	 * opt_workgroup will be used by connection functions further,
@@ -6402,7 +6419,10 @@ static int rpc_trustdom_revoke(struct net_context *c, int argc,
 
 	/* generate upper cased domain name */
 	domain_name = smb_xstrdup(argv[0]);
-	strupper_m(domain_name);
+	if (!strupper_m(domain_name)) {
+		SAFE_FREE(domain_name);
+		return -1;
+	}
 
 	/* delete password of the trust */
 	if (!pdb_del_trusteddom_pw(domain_name)) {
@@ -6971,7 +6991,11 @@ static int rpc_trustdom_list(struct net_context *c, int argc, const char **argv)
 				str[ascii_dom_name_len - 1] = '\0';
 
 			/* set opt_* variables to remote domain */
-			strupper_m(str);
+			if (!strupper_m(str)) {
+				cli_shutdown(cli);
+				talloc_destroy(mem_ctx);
+				return -1;
+			}
 			c->opt_workgroup = talloc_strdup(mem_ctx, str);
 			c->opt_target_workgroup = c->opt_workgroup;
 
diff --git a/source3/utils/net_rpc_join.c b/source3/utils/net_rpc_join.c
index 2e3e240a3f7..50383fee6b5 100644
--- a/source3/utils/net_rpc_join.c
+++ b/source3/utils/net_rpc_join.c
@@ -509,7 +509,10 @@ int net_rpc_join_newstyle(struct net_context *c, int argc, const char **argv)
 
 	/* Now store the secret in the secrets database */
 
-	strupper_m(discard_const_p(char, domain));
+	if (!strupper_m(discard_const_p(char, domain))) {
+		DEBUG(0, ("strupper_m %s failed\n", domain));
+		goto done;
+	}
 
 	if (!secrets_store_domain_sid(domain, domain_sid)) {
 		DEBUG(0, ("error storing domain sid for %s\n", domain));
diff --git a/source3/utils/ntlm_auth.c b/source3/utils/ntlm_auth.c
index 103a1f6d16e..7cf40b905de 100644
--- a/source3/utils/ntlm_auth.c
+++ b/source3/utils/ntlm_auth.c
@@ -365,9 +365,7 @@ static bool parse_ntlm_auth_domain_user(const char *domuser, fstring domain,
 	fstrcpy(user, p+1);
 	fstrcpy(domain, domuser);
 	domain[PTR_DIFF(p, domuser)] = 0;
-	strupper_m(domain);
-
-	return True;
+	return strupper_m(domain);
 }
 
 static bool get_require_membership_sid(void) {
diff --git a/source3/utils/smbcontrol.c b/source3/utils/smbcontrol.c
index 54c5d62c977..c91c0f3d167 100644
--- a/source3/utils/smbcontrol.c
+++ b/source3/utils/smbcontrol.c
@@ -1204,7 +1204,7 @@ static void my_make_nmb_name( struct nmb_name *n, const char *name, int type)
 	fstring unix_name;
 	memset( (char *)n, '\0', sizeof(struct nmb_name) );
 	fstrcpy(unix_name, name);
-	strupper_m(unix_name);
+	(void)strupper_m(unix_name);
 	push_ascii(n->name, unix_name, sizeof(n->name), STR_TERMINATE);
 	n->name_type = (unsigned int)type & 0xFF;
 	push_ascii(n->scope,  lp_netbios_scope(), 64, STR_TERMINATE);
diff --git a/source3/winbindd/idmap_ldap.c b/source3/winbindd/idmap_ldap.c
index aeeb2e87d0f..e72a0ab1849 100644
--- a/source3/winbindd/idmap_ldap.c
+++ b/source3/winbindd/idmap_ldap.c
@@ -50,7 +50,12 @@ static char *idmap_fetch_secret(const char *backend,
 	if (r < 0)
 		return NULL;
 
-	strupper_m(tmp); /* make sure the key is case insensitive */
+	/* make sure the key is case insensitive */
+	if (!strupper_m(tmp)) {
+		SAFE_FREE(tmp);
+		return NULL;
+	}
+
 	ret = secrets_fetch_generic(tmp, identity);
 
 	SAFE_FREE(tmp);
diff --git a/source3/winbindd/winbindd_ads.c b/source3/winbindd/winbindd_ads.c
index 854e12c53b6..4efd829cb9d 100644
--- a/source3/winbindd/winbindd_ads.c
+++ b/source3/winbindd/winbindd_ads.c
@@ -99,7 +99,10 @@ static ADS_STRUCT *ads_cached_connection(struct winbindd_domain *domain)
 			return NULL;
 		}
 		ads->auth.realm = SMB_STRDUP( ads->server.realm );
-		strupper_m( ads->auth.realm );
+		if (!strupper_m( ads->auth.realm )) {
+			ads_destroy( &ads );
+			return NULL;
+		}
 	}
 	else {
 		struct winbindd_domain *our_domain = domain;
@@ -114,7 +117,10 @@ static ADS_STRUCT *ads_cached_connection(struct winbindd_domain *domain)
 
 		if ( our_domain->alt_name[0] != '\0' ) {
 			ads->auth.realm = SMB_STRDUP( our_domain->alt_name );
-			strupper_m( ads->auth.realm );
+			if (!strupper_m( ads->auth.realm )) {
+				ads_destroy( &ads );
+				return NULL;
+			}
 		}
 		else
 			ads->auth.realm = SMB_STRDUP( lp_realm() );
diff --git a/source3/winbindd/winbindd_cache.c b/source3/winbindd/winbindd_cache.c
index 66de29e0613..cfa843424a3 100644
--- a/source3/winbindd/winbindd_cache.c
+++ b/source3/winbindd/winbindd_cache.c
@@ -946,7 +946,7 @@ static void wcache_save_name_to_sid(struct winbindd_domain *domain,
 	centry_put_uint32(centry, type);
 	centry_put_sid(centry, sid);
 	fstrcpy(uname, name);
-	strupper_m(uname);
+	(void)strupper_m(uname);
 	centry_end(centry, "NS/%s/%s", domain_name, uname);
 	DEBUG(10,("wcache_save_name_to_sid: %s\\%s -> %s (%s)\n", domain_name,
 		  uname, sid_string_dbg(sid), nt_errstr(status)));
@@ -1064,7 +1064,7 @@ static void wcache_save_username_alias(struct winbindd_domain *domain,
 	centry_put_string( centry, alias );
 
 	fstrcpy(uname, name);
-	strupper_m(uname);
+	(void)strupper_m(uname);
 	centry_end(centry, "NSS/NA/%s", uname);
 
 	DEBUG(10,("wcache_save_username_alias: %s -> %s\n", name, alias ));
@@ -1085,7 +1085,7 @@ static void wcache_save_alias_username(struct winbindd_domain *domain,
 	centry_put_string( centry, name );
 
 	fstrcpy(uname, alias);
-	strupper_m(uname);
+	(void)strupper_m(uname);
 	centry_end(centry, "NSS/AN/%s", uname);
 
 	DEBUG(10,("wcache_save_alias_username: %s -> %s\n", alias, name ));
@@ -1113,7 +1113,10 @@ NTSTATUS resolve_username_to_alias( TALLOC_CTX *mem_ctx,
 
 	if ( (upper_name = SMB_STRDUP(name)) == NULL )
 		return NT_STATUS_NO_MEMORY;
-	strupper_m(upper_name);
+	if (!strupper_m(upper_name)) {
+		SAFE_FREE(name);
+		return NT_STATUS_INVALID_PARAMETER;
+	}
 
 	centry = wcache_fetch(cache, domain, "NSS/NA/%s", upper_name);
 
@@ -1188,7 +1191,10 @@ NTSTATUS resolve_alias_to_username( TALLOC_CTX *mem_ctx,
 
 	if ( (upper_name = SMB_STRDUP(alias)) == NULL )
 		return NT_STATUS_NO_MEMORY;
-	strupper_m(upper_name);
+	if (!strupper_m(upper_name)) {
+		SAFE_FREE(alias);
+		return NT_STATUS_INVALID_PARAMETER;
+	}
 
 	centry = wcache_fetch(cache, domain, "NSS/AN/%s", upper_name);
 
@@ -1859,7 +1865,9 @@ static NTSTATUS name_to_sid(struct winbindd_domain *domain,
 
 		/* Only save the reverse mapping if this was not a UPN */
 		if (!strchr(name, '@')) {
-			strupper_m(discard_const_p(char, domain_name));
+			if (!strupper_m(discard_const_p(char, domain_name))) {
+				return NT_STATUS_INVALID_PARAMETER;
+			}
 			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_cm.c b/source3/winbindd/winbindd_cm.c
index 5a602422ae0..c08530e8195 100644
--- a/source3/winbindd/winbindd_cm.c
+++ b/source3/winbindd/winbindd_cm.c
@@ -767,7 +767,10 @@ static NTSTATUS get_trust_creds(const struct winbindd_domain *domain,
 			return NT_STATUS_NO_MEMORY;
 		}
 
-		strupper_m(*machine_krb5_principal);
+		if (!strupper_m(*machine_krb5_principal)) {
+			SAFE_FREE(machine_krb5_principal);
+			return NT_STATUS_INVALID_PARAMETER;
+		}
 	}
 
 	return NT_STATUS_OK;
diff --git a/source3/winbindd/winbindd_pam.c b/source3/winbindd/winbindd_pam.c
index a64cc5692c5..48bb79bdcdb 100644
--- a/source3/winbindd/winbindd_pam.c
+++ b/source3/winbindd/winbindd_pam.c
@@ -582,7 +582,9 @@ static NTSTATUS winbindd_raw_kerberos_login(TALLOC_CTX *mem_ctx,
 	parse_domain_user(user, name_domain, name_user);
 
 	realm = domain->alt_name;
-	strupper_m(realm);
+	if (!strupper_m(realm)) {
+		return NT_STATUS_INVALID_PARAMETER;
+	}
 
 	principal_s = talloc_asprintf(mem_ctx, "%s@%s", name_user, realm);
 	if (principal_s == NULL) {
@@ -938,7 +940,9 @@ static NTSTATUS winbindd_dual_pam_auth_cached(struct winbindd_domain *domain,
 			}
 
 			realm = domain->alt_name;
-			strupper_m(realm);
+			if (!strupper_m(realm)) {
+				return NT_STATUS_INVALID_PARAMETER;
+			}
 
 			principal_s = talloc_asprintf(state->mem_ctx, "%s@%s", name_user, realm);
 			if (principal_s == NULL) {
diff --git a/source3/winbindd/winbindd_util.c b/source3/winbindd/winbindd_util.c
index 52ce1e30561..656735633b6 100644
--- a/source3/winbindd/winbindd_util.c
+++ b/source3/winbindd/winbindd_util.c
@@ -877,9 +877,7 @@ bool parse_domain_user(const char *domuser, fstring domain, fstring user)
 		domain[PTR_DIFF(p, domuser)] = 0;
 	}
 
-	strupper_m(domain);
-
-	return True;
+	return strupper_m(domain);
 }
 
 bool parse_domain_user_talloc(TALLOC_CTX *mem_ctx, const char *domuser,