[Midnightbsd-cvs] src [7642] trunk/usr.bin/bsdiff/bspatch/bspatch.c: sanity checks to prevent attackers from writing data

[laffer1 at midnightbsd.org]

Revision: 7642
          http://svnweb.midnightbsd.org/src/?rev=7642
Author:   laffer1
Date:     2016-07-25 17:51:53 -0400 (Mon, 25 Jul 2016)
Log Message:
-----------
sanity checks to prevent attackers from writing data

Modified Paths:
--------------
    trunk/usr.bin/bsdiff/bspatch/bspatch.c

Modified: trunk/usr.bin/bsdiff/bspatch/bspatch.c
===================================================================
--- trunk/usr.bin/bsdiff/bspatch/bspatch.c	2016-06-26 02:16:17 UTC (rev 7641)
+++ trunk/usr.bin/bsdiff/bspatch/bspatch.c	2016-07-25 21:51:53 UTC (rev 7642)
@@ -155,6 +155,10 @@
 		};
 
 		/* Sanity-check */
+		if ((ctrl[0] < 0) || (ctrl[1] < 0))
+			errx(1,"Corrupt patch\n");
+
+		/* Sanity-check */
 		if(newpos+ctrl[0]>newsize)
 			errx(1,"Corrupt patch\n");