Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758637AbYLPPxG (ORCPT ); Tue, 16 Dec 2008 10:53:06 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1757386AbYLPPwM (ORCPT ); Tue, 16 Dec 2008 10:52:12 -0500 Received: from kumera.dghda.com ([80.68.90.171]:53427 "EHLO kumera.dghda.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756849AbYLPPwK (ORCPT ); Tue, 16 Dec 2008 10:52:10 -0500 From: "Duane Griffin" To: linux-kernel@vger.kernel.org Cc: linux-fsdevel@vger.kernel.org, Duane Griffin , Al Viro , Andrew Morton Subject: [PATCH] vfs: ensure page symlinks are NUL-terminated Date: Tue, 16 Dec 2008 15:51:54 +0000 Message-Id: <1229442720-31056-3-git-send-email-duaneg@dghda.com> X-Mailer: git-send-email 1.6.0.4 In-Reply-To: <1229442720-31056-2-git-send-email-duaneg@dghda.com> References: <1229442720-31056-1-git-send-email-duaneg@dghda.com> <1229442720-31056-2-git-send-email-duaneg@dghda.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1438 Lines: 43 On-disk data corruption could cause a page link to have its i_size set to PAGE_SIZE (or a multiple thereof) and its contents all non-NUL. NUL-terminate the link name to ensure this doesn't cause further problems for the kernel. Cc: Al Viro Cc: Andrew Morton Signed-off-by: Duane Griffin --- fs/namei.c | 7 +++++-- 1 files changed, 5 insertions(+), 2 deletions(-) diff --git a/fs/namei.c b/fs/namei.c index af3783f..2416922 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -2750,13 +2750,16 @@ int vfs_follow_link(struct nameidata *nd, const char *link) /* get the link contents into pagecache */ static char *page_getlink(struct dentry * dentry, struct page **ppage) { - struct page * page; + char *kaddr; + struct page *page; struct address_space *mapping = dentry->d_inode->i_mapping; page = read_mapping_page(mapping, 0, NULL); if (IS_ERR(page)) return (char*)page; *ppage = page; - return kmap(page); + kaddr = kmap(page); + nd_terminate_link(kaddr, dentry->d_inode->i_size, PAGE_SIZE - 1); + return kaddr; } int page_readlink(struct dentry *dentry, char __user *buffer, int buflen) -- 1.6.0.4 -- 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/