block/vpc: Add a sanity check that fixed-size images have the right type

The code in vpc.c uses BDRVVPCState->footer.type in various places to decide whether the image is a fixed-size (VHD_FIXED) or a dynamic (VHD_DYNAMIC) image. However, we never check that this field really contains VHD_FIXED if we detected a fixed size image in vpc_open(), so a wrong value here could cause quite some trouble during runtime. Suggested-by: Kevin Wolf <[email protected]> Signed-off-by: Thomas Huth <[email protected]> Message-Id: <[email protected]> Signed-off-by: Hanna Reitz <[email protected]>
httoracle · Nov 2, 2021 · 7da9623 · 7da9623
1 parent f3d43df
commit 7da9623
Showing 1 changed file with 2 additions and 1 deletion.
diff --git a/block/vpc.c b/block/vpc.c
@@ -276,7 +276,8 @@ static int vpc_open(BlockDriverState *bs, QDict *options, int flags,
         if (ret < 0) {
             goto fail;
         }
-        if (strncmp(footer->creator, "conectix", 8)) {
+        if (strncmp(footer->creator, "conectix", 8) ||
+            be32_to_cpu(footer->type) != VHD_FIXED) {
             error_setg(errp, "invalid VPC image");
             ret = -EINVAL;
             goto fail;