Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S964996AbWIFXN6 (ORCPT ); Wed, 6 Sep 2006 19:13:58 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S964883AbWIFXBX (ORCPT ); Wed, 6 Sep 2006 19:01:23 -0400 Received: from mail.kroah.org ([69.55.234.183]:62155 "EHLO perch.kroah.org") by vger.kernel.org with ESMTP id S964894AbWIFXA7 (ORCPT ); Wed, 6 Sep 2006 19:00:59 -0400 Date: Wed, 6 Sep 2006 15:55:26 -0700 From: Greg KH To: linux-kernel@vger.kernel.org, stable@kernel.org Cc: Justin Forbes , Zwane Mwaikambo , "Theodore Ts'o" , Randy Dunlap , Dave Jones , Chuck Wolber , Chris Wedgwood , torvalds@osdl.org, akpm@osdl.org, alan@lxorguk.ukuu.org.uk, Marcel Holtmann , Neil Brown , Greg Kroah-Hartman Subject: [patch 07/37] Have ext2 reject file handles with bad inode numbers early. Message-ID: <20060906225526.GH15922@kroah.com> References: <20060906224631.999046890@quad.kroah.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline; filename="have-ext2-reject-file-handles-with-bad-inode-numbers-early.patch" In-Reply-To: <20060906225444.GA15922@kroah.com> User-Agent: Mutt/1.5.13 (2006-08-11) Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2265 Lines: 80 -stable review patch. If anyone has any objections, please let us know. ------------------ From: Neil Brown This prevents bad inode numbers from triggering errors in ext2_get_inode. Signed-off-by: Neil Brown Signed-off-by: Greg Kroah-Hartman --- fs/ext2/super.c | 41 +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 41 insertions(+) --- linux-2.6.17.11.orig/fs/ext2/super.c +++ linux-2.6.17.11/fs/ext2/super.c @@ -252,6 +252,46 @@ static struct super_operations ext2_sops #endif }; +static struct dentry *ext2_get_dentry(struct super_block *sb, void *vobjp) +{ + __u32 *objp = vobjp; + unsigned long ino = objp[0]; + __u32 generation = objp[1]; + struct inode *inode; + struct dentry *result; + + if (ino != EXT2_ROOT_INO && ino < EXT2_FIRST_INO(sb)) + return ERR_PTR(-ESTALE); + if (ino > le32_to_cpu(EXT2_SB(sb)->s_es->s_inodes_count)) + return ERR_PTR(-ESTALE); + + /* iget isn't really right if the inode is currently unallocated!! + * ext2_read_inode currently does appropriate checks, but + * it might be "neater" to call ext2_get_inode first and check + * if the inode is valid..... + */ + inode = iget(sb, ino); + if (inode == NULL) + return ERR_PTR(-ENOMEM); + if (is_bad_inode(inode) + || (generation && inode->i_generation != generation) + ) { + /* we didn't find the right inode.. */ + iput(inode); + return ERR_PTR(-ESTALE); + } + /* now to find a dentry. + * If possible, get a well-connected one + */ + result = d_alloc_anon(inode); + if (!result) { + iput(inode); + return ERR_PTR(-ENOMEM); + } + return result; +} + + /* Yes, most of these are left as NULL!! * A NULL value implies the default, which works with ext2-like file * systems, but can be improved upon. @@ -259,6 +299,7 @@ static struct super_operations ext2_sops */ static struct export_operations ext2_export_ops = { .get_parent = ext2_get_parent, + .get_dentry = ext2_get_dentry, }; static unsigned long get_sb_block(void **data) -- - 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/