From: Greg KH Subject: [patch 35/39] ext4: only use i_size_high for regular files Date: Wed, 18 Feb 2009 13:33:20 -0800 Message-ID: <20090218213320.GJ19814@kroah.com> References: <20090218212144.965748151@mini.kroah.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii 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 To: linux-kernel@vger.kernel.org, stable@kernel.org Return-path: Received: from kroah.org ([198.145.64.141]:56388 "EHLO coco.kroah.org" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1757287AbZBRVgB (ORCPT ); Wed, 18 Feb 2009 16:36:01 -0500 Content-Disposition: inline; filename="ext4-only-use-i_size_high-for-regular-files.patch" In-Reply-To: <20090218213021.GA19814@kroah.com> Sender: linux-ext4-owner@vger.kernel.org List-ID: 2.6.28-stable review patch. If anyone has any objections, please let us know. ------------------ From: "Theodore Ts'o" (cherry picked from commit 06a279d636734da32bb62dd2f7b0ade666f65d7c) Directories are not allowed to be bigger than 2GB, so don't use i_size_high for anything other than regular files. E2fsck should complain about these inodes, but the simplest thing to do for the kernel is to only use i_size_high for regular files. This prevents an intentially corrupted filesystem from causing the kernel to burn a huge amount of CPU and issuing error messages such as: EXT4-fs warning (device loop0): ext4_block_to_path: block 135090028 > max Thanks to David Maciejak from Fortinet's FortiGuard Global Security Research Team for reporting this issue. http://bugzilla.kernel.org/show_bug.cgi?id=12375 Signed-off-by: "Theodore Ts'o" Signed-off-by: Greg Kroah-Hartman --- fs/ext4/ext4.h | 7 +++++-- fs/ext4/inode.c | 4 ++-- 2 files changed, 7 insertions(+), 4 deletions(-) --- a/fs/ext4/ext4.h +++ b/fs/ext4/ext4.h @@ -1188,8 +1188,11 @@ static inline void ext4_r_blocks_count_s static inline loff_t ext4_isize(struct ext4_inode *raw_inode) { - return ((loff_t)le32_to_cpu(raw_inode->i_size_high) << 32) | - le32_to_cpu(raw_inode->i_size_lo); + if (S_ISREG(le16_to_cpu(raw_inode->i_mode))) + return ((loff_t)le32_to_cpu(raw_inode->i_size_high) << 32) | + le32_to_cpu(raw_inode->i_size_lo); + else + return (loff_t) le32_to_cpu(raw_inode->i_size_lo); } static inline void ext4_isize_set(struct ext4_inode *raw_inode, loff_t i_size) --- a/fs/ext4/inode.c +++ b/fs/ext4/inode.c @@ -351,9 +351,9 @@ static int ext4_block_to_path(struct ino final = ptrs; } else { ext4_warning(inode->i_sb, "ext4_block_to_path", - "block %lu > max", + "block %lu > max in inode %lu", i_block + direct_blocks + - indirect_blocks + double_blocks); + indirect_blocks + double_blocks, inode->i_ino); } if (boundary) *boundary = final - 1 - (i_block & (ptrs - 1));