diff --git a/drivers/dahdi/dahdi-base.c b/drivers/dahdi/dahdi-base.c
index 87177a69..c78775e0 100644
--- a/drivers/dahdi/dahdi-base.c
+++ b/drivers/dahdi/dahdi-base.c
@@ -5380,7 +5380,7 @@ static int dahdi_ioctl_get_version(unsigned long data)
 {
 	struct dahdi_versioninfo vi;
 	struct ecfactory *cur;
-	size_t space = sizeof(vi.echo_canceller) - 1;
+	size_t space = sizeof(vi.echo_canceller) - 1, ec_name_len;
 	bool have_hwec = dahdi_any_hwec_available();
 
 	memset(&vi, 0, sizeof(vi));
@@ -5404,9 +5404,10 @@ static int dahdi_ioctl_get_version(unsigned long data)
 		}
 		strncat(vi.echo_canceller + strlen(vi.echo_canceller),
 			ec_name, space);
-		space -= strlen(ec_name);
-		if (space < 1)
+		ec_name_len = strlen(ec_name);
+		if (ec_name_len > space + 1)
 			break;
+		space -= ec_name_len;
 		if (cur->list.next && (cur->list.next != &ecfactory_list)) {
 			strncat(vi.echo_canceller + strlen(vi.echo_canceller),
 				", ", space);