block/qcow2-bitmap: Replace g_memdup() by g_memdup2()

Per https://discourse.gnome.org/t/port-your-module-from-g-memdup-to-g-memdup2-now/5538

  The old API took the size of the memory to duplicate as a guint,
  whereas most memory functions take memory sizes as a gsize. This
  made it easy to accidentally pass a gsize to g_memdup(). For large
  values, that would lead to a silent truncation of the size from 64
  to 32 bits, and result in a heap area being returned which is
  significantly smaller than what the caller expects. This can likely
  be exploited in various modules to cause a heap buffer overflow.

Replace g_memdup() by the safer g_memdup2() wrapper.

Trivially safe because the argument was directly from sizeof.

Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20210903174510.751630-6-philmd@redhat.com>
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>

diff --git a/block/qcow2-bitmap.c b/block/qcow2-bitmap.c
index 874ea569485100c9b0bdaf9a22e893986e259a99..256ec9987881e2a91480fe9196e0d2a266aa87f3 100644 (file)
--- a/block/qcow2-bitmap.c
+++ b/block/qcow2-bitmap.c
@@ -1609,7 +1609,7 @@ bool qcow2_store_persistent_dirty_bitmaps(BlockDriverState *bs,
                            name);
                 goto fail;
             }
-            tb = g_memdup(&bm->table, sizeof(bm->table));
+            tb = g_memdup2(&bm->table, sizeof(bm->table));
             bm->table.offset = 0;
             bm->table.size = 0;
             QSIMPLEQ_INSERT_TAIL(&drop_tables, tb, entry);