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

2 files changed, 8 insertions, 2 deletions

diff --git a/archival/tar.c b/archival/tar.c
index 1b783f0..836d127 100644
--- a/archival/tar.c
+++ b/archival/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;
diff --git a/tar.c b/tar.c
index 1b783f0..836d127 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;