commit b4295bff25f7b50de1d9cc94a9c6effd40056bca
author Philippe Mathieu-Daudé <philmd@linaro.org> Thu Apr 04 20:56:35 2024 +0200
committer Philippe Mathieu-Daudé <philmd@linaro.org> Wed Apr 10 09:09:33 2024 +0200
tree 836809e8e680772dcf9137395039f170a09f09d9
parent ba28e0ff4d95b56dc334aac2730ab3651ffc3132

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>

hw/char/virtio-serial-bus.c

diff --git a/hw/char/virtio-serial-bus.c b/hw/char/virtio-serial-bus.c
index 016aba6..2094d21 100644
--- a/hw/char/virtio-serial-bus.c
+++ b/hw/char/virtio-serial-bus.c
@@ -985,8 +985,7 @@
         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;
 }