diff --git a/drivers/block/ublk_drv.c b/drivers/block/ublk_drv.c
index 603a98a30989..ef8a0705e68b 100644
--- a/drivers/block/ublk_drv.c
+++ b/drivers/block/ublk_drv.c
@@ -1319,10 +1319,18 @@ static bool ublk_copy_user_bvec(const struct bio_vec *bv, unsigned *offset,
 
 	len = bv->bv_len - *offset;
 	bv_buf = kmap_local_page(bv->bv_page) + bv->bv_offset + *offset;
+	/*
+	 * Bio pages may originate from slab caches without a usercopy region
+	 * (e.g. jbd2 frozen metadata buffers).  This is the same data that
+	 * the loop driver writes to its backing file — no exposure risk.
+	 * The bvec length is always trusted, so the size check in
+	 * check_copy_size() is not needed either.  Use the unchecked
+	 * helpers to avoid false positives on slab pages.
+	 */
 	if (dir == ITER_DEST)
-		copied = copy_to_iter(bv_buf, len, uiter);
+		copied = _copy_to_iter(bv_buf, len, uiter);
 	else
-		copied = copy_from_iter(bv_buf, len, uiter);
+		copied = _copy_from_iter(bv_buf, len, uiter);
 
 	kunmap_local(bv_buf);