From: Tim Deegan <tim@xen.org>
Date: Thu, 12 Sep 2013 08:56:12 +0000 (+0100)
Subject: x86/mm: Don't dereference p2m pointer before NULL check.
X-Git-Tag: archive/raspbian/4.8.0-1+rpi1~1^2~6378
X-Git-Url: https://dgit.raspbian.org/?a=commitdiff_plain;h=b5f9a29421d0d2587683e3a91f0659102e80a942;p=xen.git

x86/mm: Don't dereference p2m pointer before NULL check.

Not a security bug, because in fact this is never called with a NULL
argument.

Coverity CID 1055955

Signed-off-by: Tim Deegan <tim@xen.org>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
---

diff --git a/xen/arch/x86/mm/p2m.c b/xen/arch/x86/mm/p2m.c
index f5ddd208c9..8f380ed809 100644
--- a/xen/arch/x86/mm/p2m.c
+++ b/xen/arch/x86/mm/p2m.c
@@ -453,7 +453,7 @@ void p2m_teardown(struct p2m_domain *p2m)
  * We know we don't have any extra mappings to these pages */
 {
     struct page_info *pg;
-    struct domain *d = p2m->domain;
+    struct domain *d;
     unsigned long gfn;
     p2m_type_t t;
     mfn_t mfn;
@@ -461,6 +461,8 @@ void p2m_teardown(struct p2m_domain *p2m)
     if (p2m == NULL)
         return;
 
+    d = p2m->domain;
+
     p2m_lock(p2m);
 
     /* Try to unshare any remaining shared p2m entries. Safeguard