1 files changed, 8 insertions, 0 deletions
diff --git a/block/qcow.c b/block/qcow.c
index c04ec42b58..73a96a0cd3 100644
--- a/block/qcow.c
+++ b/block/qcow.c
@@ -137,6 +137,14 @@ static int qcow_open(BlockDriverState *bs, QDict *options, int flags,
         goto fail;
     }
 
+    /* l2_bits specifies number of entries; storing a uint64_t in each entry,
+     * so bytes = num_entries << 3. */
+    if (header.l2_bits < 9 - 3 || header.l2_bits > 16 - 3) {
+        error_setg(errp, "L2 table size must be between 512 and 64k");
+        ret = -EINVAL;
+        goto fail;
+    }
+
     if (header.crypt_method > QCOW_CRYPT_AES) {
         ret = -EINVAL;
         goto fail;