diff --git a/drivers/usb/typec/altmodes/displayport.c b/drivers/usb/typec/altmodes/displayport.c
index 3f06e94771a72d0fe5bff46244af063d96cc8cb8..90bb0baed624db3ade2b22a4bb27334803c87388 100644
--- a/drivers/usb/typec/altmodes/displayport.c
+++ b/drivers/usb/typec/altmodes/displayport.c
@@ -482,7 +482,7 @@ static ssize_t pin_assignment_show(struct device *dev,
 	else
 		assignments = DP_CAP_DFP_D_PIN_ASSIGN(dp->alt->vdo);
 
-	for (i = 0; assignments; assignments >>= 1, i++) {
+	for (i = 0; assignments && i < DP_PIN_ASSIGN_MAX; assignments >>= 1, i++) {
 		if (assignments & 1) {
 			if (i == cur)
 				len += sprintf(buf + len, "[%s] ",
diff --git a/include/linux/usb/typec_dp.h b/include/linux/usb/typec_dp.h
index 55ae781d60a9ea42423c97f39dcf69d73f12a769..28f71228ae9222241e81a6465a366455ef16c33b 100644
--- a/include/linux/usb/typec_dp.h
+++ b/include/linux/usb/typec_dp.h
@@ -51,6 +51,7 @@ enum {
 	DP_PIN_ASSIGN_D,
 	DP_PIN_ASSIGN_E,
 	DP_PIN_ASSIGN_F, /* Not supported after v1.0b */
+	DP_PIN_ASSIGN_MAX,
 };
 
 /* DisplayPort alt mode specific commands */