From 55355b00b588e875583e2463beac3d5d1b53ac35 Mon Sep 17 00:00:00 2001
From: Kevin Wolf <kwolf@redhat.com>
Date: Thu, 23 Oct 2014 10:10:07 +0200
Subject: [PATCH 04/19] blockdev: Fix NULL pointer dereference in blockdev-add

Message-id: <1414059011-15516-5-git-send-email-kwolf@redhat.com>
Patchwork-id: 61838
O-Subject: [RHEL-7.1 qemu-kvm PATCH v2 4/8] blockdev: Fix NULL pointer dereference in blockdev-add
Bugzilla: 1088176
RH-Acked-by: Jeffrey Cody <jcody@redhat.com>
RH-Acked-by: Markus Armbruster <armbru@redhat.com>
RH-Acked-by: Max Reitz <mreitz@redhat.com>

If aio=native, we check that cache.direct is set as well. If however
cache wasn't specified at all, qemu just segfaulted.

The old condition didn't make any sense anyway because it effectively
only checked for the default cache mode case, but not for an explicitly
set cache.direct=off mode.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Benoit Canet <benoit@irqsave.net>
Reviewed-by: Eric Blake <eblake@redhat.com>
(cherry picked from commit c6e0bd9b7037937aafeb1d34ec17975a7d685bb7)

Trivial bonus bugfix so that the backported test 087 won't fail.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Miroslav Rezanina <mrezanin@redhat.com>
---
 blockdev.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/blockdev.c b/blockdev.c
index a2d5f02..1ac8804 100644
--- a/blockdev.c
+++ b/blockdev.c
@@ -1810,8 +1810,10 @@ void qmp_blockdev_add(BlockdevOptions *options, Error **errp)
      *
      * For now, simply forbidding the combination for all drivers will do. */
     if (options->has_aio && options->aio == BLOCKDEV_AIO_OPTIONS_NATIVE) {
-        bool direct = options->cache->has_direct && options->cache->direct;
-        if (!options->has_cache && !direct) {
+        bool direct = options->has_cache &&
+                      options->cache->has_direct &&
+                      options->cache->direct;
+        if (!direct) {
             error_setg(errp, "aio=native requires cache.direct=true");
             goto fail;
         }
-- 
1.8.3.1