From 3427c5573a7ab788e0c39e30b4d0ed5db85f03b3 Mon Sep 17 00:00:00 2001
From: Jon Maloy <jmaloy@redhat.com>
Date: Tue, 29 Jun 2021 03:42:45 -0400
Subject: [PATCH 7/9] pcnet: switch to use qemu_receive_packet() for loopback
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

RH-Author: Jon Maloy <jmaloy@redhat.com>
Message-id: <20210629034247.3286477-8-jmaloy@redhat.com>
Patchwork-id: 101791
O-Subject: [RHEL-8.4.0.z qemu-kvm PATCH v2 7/9] pcnet: switch to use qemu_receive_packet() for loopback
Bugzilla: 1932917
RH-Acked-by: Stefano Garzarella <sgarzare@redhat.com>
RH-Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
RH-Acked-by: Thomas Huth <thuth@redhat.com>

From: Alexander Bulekov <alxndr@bu.edu>

This patch switches to use qemu_receive_packet() which can detect
reentrancy and return early.

This is intended to address CVE-2021-3416.

Cc: Prasad J Pandit <ppandit@redhat.com>
Cc: qemu-stable@nongnu.org
Buglink: https://bugs.launchpad.net/qemu/+bug/1917085
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com
Signed-off-by: Alexander Bulekov <alxndr@bu.edu>
Signed-off-by: Jason Wang <jasowang@redhat.com>

(cherry picked from commit 99ccfaa1edafd79f7a3a0ff7b58ae4da7c514928)
Signed-off-by: Jon Maloy <jmaloy@redhat.com>
Signed-off-by: Danilo C. L. de Paula <ddepaula@redhat.com>
---
 hw/net/pcnet.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/hw/net/pcnet.c b/hw/net/pcnet.c
index f3f18d8598..dcd3fc4948 100644
--- a/hw/net/pcnet.c
+++ b/hw/net/pcnet.c
@@ -1250,7 +1250,7 @@ txagain:
             if (BCR_SWSTYLE(s) == 1)
                 add_crc = !GET_FIELD(tmd.status, TMDS, NOFCS);
             s->looptest = add_crc ? PCNET_LOOPTEST_CRC : PCNET_LOOPTEST_NOCRC;
-            pcnet_receive(qemu_get_queue(s->nic), s->buffer, s->xmit_pos);
+            qemu_receive_packet(qemu_get_queue(s->nic), s->buffer, s->xmit_pos);
             s->looptest = 0;
         } else {
             if (s->nic) {
-- 
2.27.0

