From: Greg KH Subject: [patch 82/87] ext4: Fix softlockup caused by illegal i_file_acl value in on-disk inode Date: Tue, 09 Jun 2009 02:40:10 -0700 Message-ID: <20090609094111.622823567@blue.kroah.org> References: <20090609093848.204935043@blue.kroah.org> Cc: Justin Forbes , Zwane Mwaikambo , Theodore Ts'o , Randy Dunlap , Dave Jones , Chuck Wolber , Chris Wedgwood , Michael Krufky , Chuck Ebbert , Domenico Andreoli , Willy Tarreau , Rodrigo Rubira Branco , Jake Edge , Eugene Teo , torvalds@linux-foundation.org, akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, linux-ext4@vger.kernel.org, Greg Kroah-Hartman To: linux-kernel@vger.kernel.org, stable@kernel.org Return-path: Received: from kroah.org ([198.145.64.141]:32863 "EHLO coco.kroah.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1760882AbZFIKWQ (ORCPT ); Tue, 9 Jun 2009 06:22:16 -0400 Content-Disposition: inline; filename=ext4-fix-softlockup-caused-by-illegal-i_file_acl-value-in-on-disk-inode.patch In-Reply-To: <20090609094451.GA26439@kroah.com> Sender: linux-ext4-owner@vger.kernel.org List-ID: 2.6.29-stable review patch. If anyone has any objections, please let us know. ------------------ From: "Theodore Ts'o" (cherry picked from commit 485c26ec70f823f2a9cf45982b724893e53a859e) If the block containing external extended attributes (which is stored in i_file_acl and i_file_acl_high) is larger than the on-disk filesystem, the process which tried to access the extended attributes will endlessly issue kernel printks complaining that "__find_get_block_slow() failed", locking up that CPU until the system is forcibly rebooted. So when we read in the inode, make sure the i_file_acl value is legal, and if not, flag the filesystem as being corrupted. Signed-off-by: "Theodore Ts'o" Signed-off-by: Greg Kroah-Hartman --- fs/ext4/inode.c | 12 ++++++++++++ 1 file changed, 12 insertions(+) --- a/fs/ext4/inode.c +++ b/fs/ext4/inode.c @@ -4351,6 +4351,18 @@ struct inode *ext4_iget(struct super_blo (__u64)(le32_to_cpu(raw_inode->i_version_hi)) << 32; } + if (ei->i_file_acl && + ((ei->i_file_acl < + (le32_to_cpu(EXT4_SB(sb)->s_es->s_first_data_block) + + EXT4_SB(sb)->s_gdb_count)) || + (ei->i_file_acl >= ext4_blocks_count(EXT4_SB(sb)->s_es)))) { + ext4_error(sb, __func__, + "bad extended attribute block %llu in inode #%lu", + ei->i_file_acl, inode->i_ino); + ret = -EIO; + goto bad_inode; + } + if (S_ISREG(inode->i_mode)) { inode->i_op = &ext4_file_inode_operations; inode->i_fop = &ext4_file_operations;