Use mkstemp rather than tempnam for security.

diff --git a/libarchive/archive_read_disk_entry_from_file.c b/libarchive/archive_read_disk_entry_from_file.c
index e10172ef3afabbd66a65aaba0b39dba4ea5df171..8b0c36512b49c4c7f16aeb382590ac3db7aa96a9 100644 (file)
--- a/libarchive/archive_read_disk_entry_from_file.c
+++ b/libarchive/archive_read_disk_entry_from_file.c
@@ -294,7 +294,8 @@ setup_mac_metadata(struct archive_read_disk *a,
        int ret = ARCHIVE_OK;
        void *buff;
        int have_attrs;
-       const char *name, *tempdir, *tempfile = NULL;
+       const char *name, *tempdir;
+       struct archive_string tempfile;
 
        (void)fd; /* UNUSED */
        name = archive_entry_sourcepath(entry);
@@ -329,26 +330,28 @@ setup_mac_metadata(struct archive_read_disk *a,
                tempdir = getenv("TMPDIR");
        if (tempdir == NULL)
                tempdir = _PATH_TMP;
-       tempfile = tempnam(tempdir, "tar.md.");
+       archive_string_init(&tempfile);
+       archive_strcpy(&tempfile, tempdir);
+       archive_strcat(&tempfile, "tar.md.XXXXXX");
+       tempfd = mkstemp(tempfile.s);
+       if (tempfd < 0) {
+               archive_set_error(&a->archive, errno,
+                   "Could not open extended attribute file");
+               ret = ARCHIVE_WARN;
+               goto cleanup;
+       }
+       __archive_ensure_cloexec_flag(tempfd);
 
        /* XXX I wish copyfile() could pack directly to a memory
         * buffer; that would avoid the temp file here.  For that
         * matter, it would be nice if fcopyfile() actually worked,
         * that would reduce the many open/close races here. */
-       if (copyfile(name, tempfile, 0, copyfile_flags | COPYFILE_PACK)) {
+       if (copyfile(name, tempfile.s, 0, copyfile_flags | COPYFILE_PACK)) {
                archive_set_error(&a->archive, errno,
                    "Could not pack extended attributes");
                ret = ARCHIVE_WARN;
                goto cleanup;
        }
-       tempfd = open(tempfile, O_RDONLY | O_CLOEXEC);
-       if (tempfd < 0) {
-               archive_set_error(&a->archive, errno,
-                   "Could not open extended attribute file");
-               ret = ARCHIVE_WARN;
-               goto cleanup;
-       }
-       __archive_ensure_cloexec_flag(tempfd);
        if (fstat(tempfd, &copyfile_stat)) {
                archive_set_error(&a->archive, errno,
                    "Could not check size of extended attributes");
@@ -371,10 +374,11 @@ setup_mac_metadata(struct archive_read_disk *a,
        archive_entry_copy_mac_metadata(entry, buff, copyfile_stat.st_size);
 
 cleanup:
-       if (tempfd >= 0)
+       if (tempfd >= 0) {
                close(tempfd);
-       if (tempfile != NULL)
-               unlink(tempfile);
+               unlink(tempfile.s);
+       }
+       archive_string_free(&tempfile);
        return (ret);
 }