svn commit: r299508 - head/tests/sys/kern

[Conrad E. Meyer]

Author: cem
Date: Thu May 12 03:44:29 2016
New Revision: 299508
URL: https://svnweb.freebsd.org/changeset/base/299508

Log:
  kern_descrip_test: Fix trivial buffer overrun with readlink(2)
  
  Reported by:	Coverity
  CID:		1229965, 1229972
  Sponsored by:	EMC / Isilon Storage Division

Modified:
  head/tests/sys/kern/kern_descrip_test.c

Modified: head/tests/sys/kern/kern_descrip_test.c
==============================================================================
--- head/tests/sys/kern/kern_descrip_test.c	Thu May 12 03:37:17 2016	(r299507)
+++ head/tests/sys/kern/kern_descrip_test.c	Thu May 12 03:44:29 2016	(r299508)
@@ -27,6 +27,7 @@
 #include <sys/cdefs.h>
 __FBSDID("$FreeBSD$");
 
+#include <sys/param.h>
 #include <errno.h>
 #include <fcntl.h>
 #include <signal.h>
@@ -170,7 +171,7 @@ ATF_TC_CLEANUP(kern_maxfiles__increase, 
 	char buf[80];
 
 	if ((n = readlink(VALUE, buf, sizeof(buf))) > 0) {
-		buf[n] = '\0';
+		buf[MIN((size_t)n, sizeof(buf) - 1)] = '\0';
 		if (sscanf(buf, "%d", &oldmaxfiles) == 1) {
 			oldlen = sizeof(oldmaxfiles);
 			(void) sysctlbyname("kern.maxfiles", NULL, 0,