diff --git a/fs/exfat/dir.c b/fs/exfat/dir.c
index 7446bf09a04a..8ee3c99e2666 100644
--- a/fs/exfat/dir.c
+++ b/fs/exfat/dir.c
@@ -741,9 +741,15 @@ static bool exfat_validate_entry(unsigned int type,
 struct exfat_dentry *exfat_get_dentry_cached(
 	struct exfat_entry_set_cache *es, int num)
 {
-	int off = es->start_off + num * DENTRY_SIZE;
-	struct buffer_head *bh = es->bh[EXFAT_B_TO_BLK(off, es->sb)];
-	char *p = bh->b_data + EXFAT_BLK_OFFSET(off, es->sb);
+	struct buffer_head *bh;
+	int off;
+	char *p;
+
+	if (check_add_overflow(es->start_off, num * DENTRY_SIZE, &off))
+		return NULL;
+
+	bh = es->bh[EXFAT_B_TO_BLK(off, es->sb)];
+	p = bh->b_data + EXFAT_BLK_OFFSET(off, es->sb);
 
 	return (struct exfat_dentry *)p;
 }