[PATCH] tools/xenstore: fix use after free bug in xenstore_control

From: Juergen Gross <jgross@suse.com>
To: xen-devel@lists.xenproject.org
Cc: Juergen Gross <jgross@suse.com>, Ian Jackson <iwj@xenproject.org>,
	Wei Liu <wl@xen.org>
Subject: [PATCH] tools/xenstore: fix use after free bug in xenstore_control
Date: Mon, 25 Jan 2021 08:23:31 +0100	[thread overview]
Message-ID: <20210125072331.22093-1-jgross@suse.com> (raw)

There is a very unlikely use after free bug and a memory leak in
live_update_start() of xenstore_control. Fix those.

Coverity-Id: 1472399
Fixes: 7f97193e6aa858 ("tools/xenstore: add live update command to xenstore-control")
Signed-off-by: Juergen Gross <jgross@suse.com>
---
 tools/xenstore/xenstore_control.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/tools/xenstore/xenstore_control.c b/tools/xenstore/xenstore_control.c
index 0c95cf767c..f6f4626c06 100644
--- a/tools/xenstore/xenstore_control.c
+++ b/tools/xenstore/xenstore_control.c
@@ -43,7 +43,12 @@ static int live_update_start(struct xs_handle *xsh, bool force, unsigned int to)
     if (len < 0)
         return 1;
 
+    ret = strdup("BUSY");
+    if (!ret)
+        return 1;
+
     for (time_start = time(NULL); time(NULL) - time_start < to;) {
+        free(ret);
         ret = xs_control_command(xsh, "live-update", buf, len);
         if (!ret)
             goto err;
-- 
2.26.2


