hw/char/virtio-serial-bus: Protect from DMA re-entrancy bugs

Replace qemu_bh_new_guarded() by virtio_bh_new_guarded()
so the bus and device use the same guard. Otherwise the
DMA-reentrancy protection can be bypassed.

Fixes: CVE-2024-3446
Cc: qemu-stable@nongnu.org
Suggested-by: Alexander Bulekov <alxndr@bu.edu>
Reviewed-by: Gerd Hoffmann <kraxel@redhat.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Message-Id: <20240409105537.18308-4-philmd@linaro.org>

diff --git a/hw/char/virtio-serial-bus.c b/hw/char/virtio-serial-bus.c
index 016aba637405e93591611af16332eb0a1594a7a3..2094d213cdf312a28d2815822bb9eef31657e32d 100644 (file)
--- a/hw/char/virtio-serial-bus.c
+++ b/hw/char/virtio-serial-bus.c
@@ -985,8 +985,7 @@ static void virtser_port_device_realize(DeviceState *dev, Error **errp)
         return;
     }
 
-    port->bh = qemu_bh_new_guarded(flush_queued_data_bh, port,
-                                   &dev->mem_reentrancy_guard);
+    port->bh = virtio_bh_new_guarded(dev, flush_queued_data_bh, port);
     port->elem = NULL;
 }