readlink(2) does not NULL terminate the buffer it reads in, but tar expected it

to do so.  This caused symlinks stored in tarballs to likely have trailing
crap in the stored symlink named.  Oops.
 -Erik


git-svn-id: svn://busybox.net/trunk/busybox@702 69ca8d6d-28ef-0310-b511-8ec308f3f277

1 files changed, 4 insertions, 1 deletions

diff --git a/tar.c b/tar.c
index 1b783f0f5..836d127e7 100644
--- a/tar.c
+++ b/tar.c
@@ -824,12 +824,15 @@ writeTarHeader(struct TarBallInfo *tbInfo, const char *fileName, struct stat *st
 
         /* WARNING/NOTICE: I break Hard Links */
         if (S_ISLNK(statbuf->st_mode)) {
+                int link_size=0;
                 char buffer[BUFSIZ];
                 header.typeflag  = SYMTYPE;
-                if ( readlink(fileName, buffer, sizeof(buffer) - 1) < 0) {
+                link_size = readlink(fileName, buffer, sizeof(buffer) - 1);
+                if ( link_size < 0) {
                         errorMsg("Error reading symlink '%s': %s\n", header.name, strerror(errno));
                         return ( FALSE);
                 }
+                buffer[link_size] = '\0';
                 strncpy(header.linkname, buffer, sizeof(header.linkname)); 
         } else if (S_ISDIR(statbuf->st_mode)) {
                 header.typeflag  = DIRTYPE;