From: Daniel Kiper <daniel.kiper@oracle.com>
Date: Mon, 2 Dec 2013 19:13:03 +0000 (+0100)
Subject: libxenctrl: Fix xc_interface_close() crash if it gets NULL as an argument
X-Git-Tag: archive/raspbian/4.8.0-1+rpi1~1^2~5820
X-Git-Url: https://dgit.raspbian.org/%22http://www.example.com/cgi/success//%22http:/www.example.com/cgi/success/?a=commitdiff_plain;h=2cebe22e6924439535cbf4a9f82a7d9d30c8f9c7;p=xen.git

libxenctrl: Fix xc_interface_close() crash if it gets NULL as an argument

xc_interface_close() crashes if it gets NULL as an argument. However,
it just calls xc_interface_close_common() which is called by many
others functions. It means that they are also vulnerable. So fix above
mentioned issue by adding NULL check in xc_interface_close_common().
This way we fix similar issue in other functions which calls
xc_interface_close_common() too.

Signed-off-by: Daniel Kiper <daniel.kiper@oracle.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
---

diff --git a/tools/libxc/xc_private.c b/tools/libxc/xc_private.c
index 524862e9e6..838fd21f23 100644
--- a/tools/libxc/xc_private.c
+++ b/tools/libxc/xc_private.c
@@ -198,6 +198,9 @@ static int xc_interface_close_common(xc_interface *xch)
 {
     int rc = 0;
 
+    if (!xch)
+	return 0;
+
     xc__hypercall_buffer_cache_release(xch);
 
     xtl_logger_destroy(xch->dombuild_logger_tofree);