[PATCH v2 4/8] vhost-user-gpu: fix memory leak while calling 'vg_resource_unref' (CVE-2021-3544)

[Li Qiang]

If the guest trigger following sequences, the attach_backing will be leaked:

        vg_resource_create_2d
        vg_resource_attach_backing
        vg_resource_unref

This patch fix this by freeing 'res->iov' in vg_resource_destroy.

Fixes: CVE-2021-3544
Reported-by: Li Qiang <liq3ea@163.com>
virtio-gpu fix: 5e8e3c4c75 ("virtio-gpu: fix resource leak
in virgl_cmd_resource_unref")

Reviewed-by: Prasad J Pandit <pjp@fedoraproject.org>
Signed-off-by: Li Qiang <liq3ea@163.com>
---
 contrib/vhost-user-gpu/vhost-user-gpu.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/contrib/vhost-user-gpu/vhost-user-gpu.c 
b/contrib/vhost-user-gpu/vhost-user-gpu.c
index 0437e52b64..770dfad529 100644
--- a/contrib/vhost-user-gpu/vhost-user-gpu.c
+++ b/contrib/vhost-user-gpu/vhost-user-gpu.c
@@ -400,6 +400,7 @@ vg_resource_destroy(VuGpu *g,
     }
 
     vugbm_buffer_destroy(&res->buffer);
+    g_free(res->iov);
     pixman_image_unref(res->image);
     QTAILQ_REMOVE(&g->reslist, res, next);
     g_free(res);
-- 
2.25.1