Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933177AbbEKSg3 (ORCPT ); Mon, 11 May 2015 14:36:29 -0400 Received: from zeniv.linux.org.uk ([195.92.253.2]:47051 "EHLO ZenIV.linux.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752129AbbEKSIS (ORCPT ); Mon, 11 May 2015 14:08:18 -0400 From: Al Viro To: Linus Torvalds Cc: Neil Brown , Christoph Hellwig , linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org Subject: [PATCH v3 034/110] namei: expand nested_symlink() in its only caller Date: Mon, 11 May 2015 19:06:54 +0100 Message-Id: <1431367690-5223-34-git-send-email-viro@ZenIV.linux.org.uk> X-Mailer: git-send-email 1.7.7.6 In-Reply-To: <20150511180650.GA4147@ZenIV.linux.org.uk> References: <20150511180650.GA4147@ZenIV.linux.org.uk> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2276 Lines: 94 From: Al Viro Signed-off-by: Al Viro --- fs/namei.c | 61 +++++++++++++++++++++++-------------------------------------- 1 file changed, 23 insertions(+), 38 deletions(-) diff --git a/fs/namei.c b/fs/namei.c index 8582907..7fcda91 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -1613,43 +1613,6 @@ 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: * @@ -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; } -- 2.1.4 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/