libxc: fix retrieval of and remove pointless check on gzip size

Coverity-ID: 1055587
Coverity-ID: 1055963
Signed-off-by: Matthew Daley <mattjd@gmail.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>

diff --git a/tools/libxc/xc_dom_core.c b/tools/libxc/xc_dom_core.c
index 0f367f6b8b5f7c7b534d787c3f1206e97ee57417..3bf51efd647e7b1d7de8636c3296faa4a5da1e22 100644 (file)
--- a/tools/libxc/xc_dom_core.c
+++ b/tools/libxc/xc_dom_core.c
@@ -294,8 +294,8 @@ size_t xc_dom_check_gzip(xc_interface *xch, void *blob, size_t ziplen)
         return 0;
 
     gzlen = blob + ziplen - 4;
-    unziplen = gzlen[3] << 24 | gzlen[2] << 16 | gzlen[1] << 8 | gzlen[0];
-    if ( (unziplen < 0) || (unziplen > XC_DOM_DECOMPRESS_MAX) )
+    unziplen = (size_t)gzlen[3] << 24 | gzlen[2] << 16 | gzlen[1] << 8 | gzlen[0];
+    if ( unziplen > XC_DOM_DECOMPRESS_MAX )
     {
         xc_dom_printf
             (xch,