Do an explicit "is filename sane" check

Until now, filenames containing '/' or being equal to '..' or '.' where
not handled explicitly, because they are canonicalized later, which
will then fail.

This commit adds an explicit check to make those fail immediately with
a clear, specific error message.

Signed-off-by: David Oberhollenzer <david.oberhollenzer@sigma-star.at>

1 files changed, 10 insertions, 0 deletions

diff --git a/tar/sqfs2tar.c b/tar/sqfs2tar.c
index 3e64b45..1e05cd4 100644
--- a/tar/sqfs2tar.c
+++ b/tar/sqfs2tar.c
@@ -266,6 +266,16 @@ static int write_tree_dfs(const sqfs_tree_node_t *n)
 	if (n->parent == NULL && S_ISDIR(n->inode->base.mode))
 		goto skip_hdr;
 
+	if (!is_filename_sane((const char *)n->name)) {
+		fprintf(stderr, "Found a file named '%s', skipping.\n",
+			n->name);
+		if (dont_skip) {
+			fputs("Not allowed to skip files, aborting!\n", stderr);
+			return -1;
+		}
+		return 0;
+	}
+
 	name = sqfs_tree_node_get_path(n);
 	if (name == NULL) {
 		perror("resolving tree node path");