From 1cbb554a4057afd4d71c04757ef7fd1bbb7114ee Mon Sep 17 00:00:00 2001
From: Jon Maloy <jmaloy@redhat.com>
Date: Tue, 29 Jun 2021 03:42:46 -0400
Subject: [PATCH 8/9] cadence_gem: switch to use qemu_receive_packet() for
 loopback
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RH-Author: Jon Maloy <jmaloy@redhat.com>
Message-id: <20210629034247.3286477-9-jmaloy@redhat.com>
Patchwork-id: 101793
O-Subject: [RHEL-8.4.0.z qemu-kvm PATCH v2 8/9] cadence_gem: 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
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 e73adfbeec9d4e008630c814759052ed945c3fed)
Conflict: upstream commit 24d62fd5028e ("net: cadence_gem: Move tx/rx
packet buffert to CadenceGEMState") is missing in this version, so
we stick to using the original stack variable tx_packet in the calls.

Signed-off-by: Jon Maloy <jmaloy@redhat.com>
Signed-off-by: Danilo C. L. de Paula <ddepaula@redhat.com>
---
 hw/net/cadence_gem.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/hw/net/cadence_gem.c b/hw/net/cadence_gem.c
index b8be73dc55..be7c91123b 100644
--- a/hw/net/cadence_gem.c
+++ b/hw/net/cadence_gem.c
@@ -1225,8 +1225,8 @@ static void gem_transmit(CadenceGEMState *s)
                 /* Send the packet somewhere */
                 if (s->phy_loop || (s->regs[GEM_NWCTRL] &
                                     GEM_NWCTRL_LOCALLOOP)) {
-                    gem_receive(qemu_get_queue(s->nic), tx_packet,
-                                total_bytes);
+                    qemu_receive_packet(qemu_get_queue(s->nic), tx_packet,
+                                        total_bytes);
                 } else {
                     qemu_send_packet(qemu_get_queue(s->nic), tx_packet,
                                      total_bytes);
-- 
2.27.0

