From: Al Viro <viro@xxxxxxxxxxxxxxxxxx> Signed-off-by: Al Viro <viro@xxxxxxxxxxxxxxxxxx> --- fs/namei.c | 61 +++++++++++++++++++++++-------------------------------------- 1 file changed, 23 insertions(+), 38 deletions(-) diff --git a/fs/namei.c b/fs/namei.c index c5d5e9e..fae70a4 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -1605,43 +1605,6 @@ out_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: * @@ -1831,7 +1794,29 @@ 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; } -- 2.1.4 -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html