From mboxrd@z Thu Jan 1 00:00:00 1970 Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932229AbdBETaC (ORCPT + 2 others); Sun, 5 Feb 2017 14:30:02 -0500 Received: from wtarreau.pck.nerim.net ([62.212.114.60]:28581 "EHLO 1wt.eu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932195AbdBETaA (ORCPT ); Sun, 5 Feb 2017 14:30:00 -0500 From: Willy Tarreau To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, linux@roeck-us.net Cc: Daeho Jeong , Hobin Woo , "Theodore Ts'o" , Willy Tarreau Subject: [PATCH 3.10 153/319] ext4: reinforce check of i_dtime when clearing high fields of uid and gid Date: Sun, 5 Feb 2017 20:19:35 +0100 Message-Id: <1486322541-8206-54-git-send-email-w@1wt.eu> X-Mailer: git-send-email 2.8.0.rc2.1.gbe9624a In-Reply-To: <1486322541-8206-1-git-send-email-w@1wt.eu> References: <1486322541-8206-1-git-send-email-w@1wt.eu> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Return-Path: From: Daeho Jeong commit 93e3b4e6631d2a74a8cf7429138096862ff9f452 upstream. Now, ext4_do_update_inode() clears high 16-bit fields of uid/gid of deleted and evicted inode to fix up interoperability with old kernels. However, it checks only i_dtime of an inode to determine whether the inode was deleted and evicted, and this is very risky, because i_dtime can be used for the pointer maintaining orphan inode list, too. We need to further check whether the i_dtime is being used for the orphan inode list even if the i_dtime is not NULL. We found that high 16-bit fields of uid/gid of inode are unintentionally and permanently cleared when the inode truncation is just triggered, but not finished, and the inode metadata, whose high uid/gid bits are cleared, is written on disk, and the sudden power-off follows that in order. Signed-off-by: Daeho Jeong Signed-off-by: Hobin Woo Signed-off-by: Theodore Ts'o Signed-off-by: Willy Tarreau --- fs/ext4/inode.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c index 046e0e1..a187055 100644 --- a/fs/ext4/inode.c +++ b/fs/ext4/inode.c @@ -4480,14 +4480,14 @@ static int ext4_do_update_inode(handle_t *handle, * Fix up interoperability with old kernels. Otherwise, old inodes get * re-used with the upper 16 bits of the uid/gid intact */ - if (!ei->i_dtime) { + if (ei->i_dtime && list_empty(&ei->i_orphan)) { + raw_inode->i_uid_high = 0; + raw_inode->i_gid_high = 0; + } else { raw_inode->i_uid_high = cpu_to_le16(high_16_bits(i_uid)); raw_inode->i_gid_high = cpu_to_le16(high_16_bits(i_gid)); - } else { - raw_inode->i_uid_high = 0; - raw_inode->i_gid_high = 0; } } else { raw_inode->i_uid_low = cpu_to_le16(fs_high2lowuid(i_uid)); -- 2.8.0.rc2.1.gbe9624a