From 15847279f29b0bd67b95daefff395cab8fad80d3 Mon Sep 17 00:00:00 2001
From: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Date: Tue, 24 Mar 2020 18:36:30 +0300
Subject: [PATCH 4/5] qga/commands-posix: fix use after free of local_err

local_err is used several times in guest_suspend(). Setting non-NULL
local_err will crash, so let's zero it after freeing. Also fix possible
leak of local_err in final if().

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20200324153630.11882-7-vsementsov@virtuozzo.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Zhenyu Ye <yezhenyu2@huawei.com>
---
 qga/commands-posix.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/qga/commands-posix.c b/qga/commands-posix.c
index dfc05f5b..66164e6c 100644
--- a/qga/commands-posix.c
+++ b/qga/commands-posix.c
@@ -1760,6 +1760,7 @@ static void guest_suspend(SuspendMode mode, Error **errp)
     }
 
     error_free(local_err);
+    local_err = NULL;
 
     if (pmutils_supports_mode(mode, &local_err)) {
         mode_supported = true;
@@ -1771,6 +1772,7 @@ static void guest_suspend(SuspendMode mode, Error **errp)
     }
 
     error_free(local_err);
+    local_err = NULL;
 
     if (linux_sys_state_supports_mode(mode, &local_err)) {
         mode_supported = true;
@@ -1778,6 +1780,7 @@ static void guest_suspend(SuspendMode mode, Error **errp)
     }
 
     if (!mode_supported) {
+        error_free(local_err);
         error_setg(errp,
                    "the requested suspend mode is not supported by the guest");
     } else {
-- 
2.22.0.windows.1

