Commit 5a460275 authored by Al Viro's avatar Al Viro
Browse files

namei: expand nested_symlink() in its only caller 



Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
parent 896475d5

fs/namei.c

+23 −38
Original line number Diff line number Diff line
@@ -1612,43 +1612,6 @@ static int walk_component(struct nameidata *nd, int follow) 
	return err;

}



/*

 * This limits recursive symlink follows to 8, while

 * limiting consecutive symlinks to 40.

 *

 * Without that kind of total limit, nasty chains of consecutive

 * symlinks can cause almost arbitrarily long lookups.

 */

static inline int nested_symlink(struct nameidata *nd)

{

	int res;



	if (unlikely(current->link_count >= MAX_NESTED_LINKS)) {

		path_put_conditional(&nd->link, nd);

		path_put(&nd->path);

		return -ELOOP;

	}

	BUG_ON(nd->depth >= MAX_NESTED_LINKS);



	nd->depth++;

	current->link_count++;



	do {

		struct path link = nd->link;

		void *cookie;



		res = follow_link(&link, nd, &cookie);

		if (res)

			break;

		res = walk_component(nd, LOOKUP_FOLLOW);

		put_link(nd, &link, cookie);

	} while (res > 0);



	current->link_count--;

	nd->depth--;

	return res;

}



/*

 * We can do the critical dentry name comparison and hashing

 * operations one word at a time, but we are limited to:
@@ -1839,7 +1802,29 @@ static int link_path_walk(const char *name, struct nameidata *nd) 
			return err;



		if (err) {

			err = nested_symlink(nd);

			if (unlikely(current->link_count >= MAX_NESTED_LINKS)) {

				path_put_conditional(&nd->link, nd);

				path_put(&nd->path);

				return -ELOOP;

			}

			BUG_ON(nd->depth >= MAX_NESTED_LINKS);



			nd->depth++;

			current->link_count++;



			do {

				struct path link = nd->link;

				void *cookie;



				err = follow_link(&link, nd, &cookie);

				if (err)

					break;

				err = walk_component(nd, LOOKUP_FOLLOW);

				put_link(nd, &link, cookie);

			} while (err > 0);



			current->link_count--;

			nd->depth--;

			if (err)

				return err;

		}