From: Andrei Borzenkov <arvidjaar@gmail.com>
Date: Mon, 6 Apr 2015 16:25:02 +0000 (+0300)
Subject: core: avoid NULL derefrence in grub_divmod64s
X-Git-Tag: 2.02-beta3~338
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=f11db3c7fc50b0b7de22e5ccdcb06bcbccb22a46;p=thirdparty%2Fgrub.git

core: avoid NULL derefrence in grub_divmod64s

It can be called with NULL for third argument.  grub_divmod32* for
now are called only from within wrappers, so skip check.

Reported-By: Michael Zimmermann <sigmaepsilon92@gmail.com>
---

diff --git a/grub-core/lib/division.c b/grub-core/lib/division.c
index 920a79f18..35606fea7 100644
--- a/grub-core/lib/division.c
+++ b/grub-core/lib/division.c
@@ -50,7 +50,8 @@ grub_divmod64s (grub_int64_t n,
       q = -q;
     }
   /* Now: n = d * q + r  */
-  *ro = r;
+  if (ro)
+    *ro = r;
   return q;
 }