From: Alexander Bulekov <alxndr@bu.edu>
Date: Mon, 1 Mar 2021 15:33:34 +0000 (-0500)
Subject: pcnet: switch to use qemu_receive_packet() for loopback
X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=99ccfaa1edafd79f7a3a0ff7b58ae4da7c514928;p=qemu.git

pcnet: switch to use qemu_receive_packet() for loopback

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>
---

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) {