svn commit: r195988 - head/usr.bin/gzip

[Xin LI]

Author: delphij
Date: Fri Jul 31 08:37:27 2009
New Revision: 195988
URL: http://svn.freebsd.org/changeset/base/195988

Log:
  Correct a stack underflow in gzip:
  
   - Limit suffix to be no more than 30 bytes long.  This matches GNU
     behavior.
   - Correct usage of memcpy().
  
  Note that this commit only corrects the stack underflow issue, we
  still need some other fixes to cover other edges. [1]
  
  Reported by:	Ron Jude <ronj wytheville org>
  Discussed with:	Matthew Green (original NetBSD gzip author),
  		Eygene Ryabinkin <rea-fbsd codelabs ru> [1]
  Approved by:	re (kib)

Modified:
  head/usr.bin/gzip/gzip.c

Modified: head/usr.bin/gzip/gzip.c
==============================================================================
--- head/usr.bin/gzip/gzip.c	Fri Jul 31 07:53:09 2009	(r195987)
+++ head/usr.bin/gzip/gzip.c	Fri Jul 31 08:37:27 2009	(r195988)
@@ -150,6 +150,8 @@ static suffixes_t suffixes[] = {
 };
 #define NUM_SUFFIXES (sizeof suffixes / sizeof suffixes[0])
 
+#define SUFFIX_MAXLEN	30
+
 static	const char	gzip_version[] = "FreeBSD gzip 20090621";
 
 #ifndef SMALL
@@ -372,6 +374,8 @@ main(int argc, char **argv)
 		case 'S':
 			len = strlen(optarg);
 			if (len != 0) {
+				if (len > SUFFIX_MAXLEN)
+					errx(1, "incorrect suffix: '%s': too long", optarg);
 				suffixes[0].zipped = optarg;
 				suffixes[0].ziplen = len;
 			} else {
@@ -1236,7 +1240,7 @@ file_compress(char *file, char *outfile,
 		/* Add (usually) .gz to filename */
 		if ((size_t)snprintf(outfile, outsize, "%s%s",
 					file, suffixes[0].zipped) >= outsize)
-			memcpy(outfile - suffixes[0].ziplen - 1,
+			memcpy(outfile + outsize - suffixes[0].ziplen - 1,
 				suffixes[0].zipped, suffixes[0].ziplen + 1);
 
 #ifndef SMALL