- Reduce buffer size from LINE_MAX to PATH_MAX, there is no point to store

path longer than this.
 - Fix an unreached case of check against sizeof buf, which in turn leads
   to an off-by-one nul byte write on the stack.  The original condition
   can never be satisfied because the passed boundary is the maximum value
   that can be returned, so code was harmless.

MFC after:	1 month
This commit is contained in:
delphij 2012-12-21 22:20:59 +00:00
parent 68ab69513c
commit 23ae20eae2

View File

@ -35,32 +35,28 @@ __FBSDID("$FreeBSD$");
* are threaded, so I'm not concerned about cancellation points or other
* niceties.
*/
#include <sys/limits.h>
#include <limits.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#ifndef LINE_MAX
#define LINE_MAX _POSIX2_LINE_MAX
#endif
#define _PATH_UTIL_COMPAT "/etc/compat-FreeBSD-4-util"
#define _ENV_UTIL_COMPAT "_COMPAT_FreeBSD_4"
int
check_utility_compat(const char *utility)
{
char buf[LINE_MAX];
char buf[PATH_MAX];
char *p, *bp;
int len;
if ((p = getenv(_ENV_UTIL_COMPAT)) != NULL) {
strlcpy(buf, p, sizeof buf);
} else {
if ((len = readlink(_PATH_UTIL_COMPAT, buf, sizeof buf)) < 0)
if ((len = readlink(_PATH_UTIL_COMPAT, buf, sizeof(buf) - 1)) < 0)
return 0;
if (len > sizeof buf)
len = sizeof buf;
buf[len] = '\0';
}
if (buf[0] == '\0')