From bd9de3a28ae6721d5ccf1d14acf259b3e6f4093c Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Philippe=20Mathieu-Daud=C3=A9?= <philmd@redhat.com>
Date: Wed, 19 Jun 2019 16:03:38 +0200
Subject: [PATCH 1/2] qxl: check release info object
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RH-Author: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-id: <20190619160338.15430-2-philmd@redhat.com>
Patchwork-id: 88733
O-Subject: [RHEL-7.7 qemu-kvm PATCH 1/1] qxl: check release info object
Bugzilla: 1732337
RH-Acked-by: Christophe de Dinechin <cdupontd@redhat.com>
RH-Acked-by: Gerd Hoffmann <kraxel@redhat.com>
RH-Acked-by: Laszlo Ersek <lersek@redhat.com>

From: Prasad J Pandit <pjp@fedoraproject.org>

When releasing spice resources in release_resource() routine,
if release info object 'ext.info' is null, it leads to null
pointer dereference. Add check to avoid it.

Reported-by: Bugs SysSec <bugs-syssec@rub.de>
Signed-off-by: Prasad J Pandit <pjp@fedoraproject.org>
Message-id: 20190425063534.32747-1-ppandit@redhat.com
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
(cherry picked from commit d52680fc932efb8a2f334cc6993e705ed1e31e99)
Signed-off-by: Miroslav Rezanina <mrezanin@redhat.com>
---
 hw/display/qxl.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/hw/display/qxl.c b/hw/display/qxl.c
index 0625a76..d493101 100644
--- a/hw/display/qxl.c
+++ b/hw/display/qxl.c
@@ -735,6 +735,9 @@ static void interface_release_resource(QXLInstance *sin,
     QXLReleaseRing *ring;
     uint64_t *item, id;
 
+    if (!ext.info) {
+        return;
+    }
     if (ext.group_id == MEMSLOT_GROUP_HOST) {
         /* host group -> vga mode update request */
         qemu_spice_destroy_update(&qxl->ssd, (void *)(intptr_t)ext.info->id);
-- 
1.8.3.1