parallels: Check maximum cluster size on create

It's unclear what the real maximum cluster size is for the Parallels
format, but let's at least make sure that we don't get integer
overflows in our .bdrv_co_create implementation.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>

diff --git a/block/parallels.c b/block/parallels.c
index e2515dec812cccf9ec792b3f01b91815f6e5fd70..799215e079fe982d0e2fa59f47001594de796237 100644 (file)
--- a/block/parallels.c
+++ b/block/parallels.c
@@ -526,6 +526,11 @@ static int coroutine_fn parallels_co_create(BlockdevCreateOptions* opts,
         cl_size = DEFAULT_CLUSTER_SIZE;
     }
 
+    /* XXX What is the real limit here? This is an insanely large maximum. */
+    if (cl_size >= INT64_MAX / MAX_PARALLELS_IMAGE_FACTOR) {
+        error_setg(errp, "Cluster size is too large");
+        return -EINVAL;
+    }
     if (total_size >= MAX_PARALLELS_IMAGE_FACTOR * cl_size) {
         error_setg(errp, "Image size is too large for this cluster size");
         return -E2BIG;