From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934449Ab3GQWzR (ORCPT ); Wed, 17 Jul 2013 18:55:17 -0400 Received: from youngberry.canonical.com ([91.189.89.112]:56565 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934276Ab3GQWzN (ORCPT ); Wed, 17 Jul 2013 18:55:13 -0400 From: Kamal Mostafa To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Cc: Jan Kara , "Theodore Ts'o" , Luis Henriques Subject: [PATCH 085/145] ext4: fix overflow when counting used blocks on 32-bit architectures Date: Wed, 17 Jul 2013 15:46:57 -0700 Message-Id: <1374101277-7915-86-git-send-email-kamal@canonical.com> X-Mailer: git-send-email 1.8.1.2 In-Reply-To: <1374101277-7915-1-git-send-email-kamal@canonical.com> References: <1374101277-7915-1-git-send-email-kamal@canonical.com> X-Extended-Stable: 3.8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.8.13.5 -stable review patch. If anyone has any objections, please let me know. ------------------ From: Jan Kara commit 8af8eecc1331dbf5e8c662022272cf667e213da5 upstream. The arithmetics adding delalloc blocks to the number of used blocks in ext4_getattr() can easily overflow on 32-bit archs as we first multiply number of blocks by blocksize and then divide back by 512. Make the arithmetics more clever and also use proper type (unsigned long long instead of unsigned long). Signed-off-by: Jan Kara Signed-off-by: Theodore Ts'o Signed-off-by: Luis Henriques --- fs/ext4/inode.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c index c0fbd96..1ec8761 100644 --- a/fs/ext4/inode.c +++ b/fs/ext4/inode.c @@ -4523,7 +4523,7 @@ int ext4_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat) { struct inode *inode; - unsigned long delalloc_blocks; + unsigned long long delalloc_blocks; inode = dentry->d_inode; generic_fillattr(inode, stat); @@ -4541,7 +4541,7 @@ int ext4_getattr(struct vfsmount *mnt, struct dentry *dentry, delalloc_blocks = EXT4_C2B(EXT4_SB(inode->i_sb), EXT4_I(inode)->i_reserved_data_blocks); - stat->blocks += (delalloc_blocks << inode->i_sb->s_blocksize_bits)>>9; + stat->blocks += delalloc_blocks << (inode->i_sb->s_blocksize_bits-9); return 0; } -- 1.8.1.2