vfio/igd: Fix potential overflow in igd_gtt_memory_size()

The risk is mainly theoretical since the applied bit mask will keep
the 'ggms' shift value below 3. Nevertheless, let's use a 64 bit
integer type and resolve the coverity issue.

Resolves: Coverity CID 1585908
Fixes: 1e1eac5f3dcd ("vfio/igd: canonicalize memory size calculations")
Reviewed-by: Alex Williamson <alex.williamson@redhat.com>
Link: https://lore.kernel.org/r/20250107130604.669697-1-clg@redhat.com
Signed-off-by: Cédric Le Goater <clg@redhat.com>

diff --git a/hw/vfio/igd.c b/hw/vfio/igd.c
index 0740a5dd8cc9346a92c4613194faa8dea42e1d98..b5303ea565d6a344d0a43273f288bbb4a7f48327 100644 (file)
--- a/hw/vfio/igd.c
+++ b/hw/vfio/igd.c
@@ -133,7 +133,7 @@ static uint64_t igd_gtt_memory_size(int gen, uint16_t gmch)
     } else {
         ggms = (gmch >> IGD_GMCH_GEN8_GGMS_SHIFT) & IGD_GMCH_GEN8_GGMS_MASK;
         if (ggms != 0) {
-            ggms = 1 << ggms;
+            ggms = 1ULL << ggms;
         }
     }