From: Djalal Harouni Subject: [PATCH] fs/ext{3,4}: fix potential race when setversion ioctl updates inode Date: Tue, 3 Jan 2012 02:31:52 +0100 Message-ID: <20120103013152.GA26455@dztty> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: linux-ext4@vger.kernel.org, linux-kernel@vger.kernel.org, Al Viro To: Jan Kara , Andrew Morton , Andreas Dilger , Theodore Ts'o , Yongqiang Yang Return-path: Received: from numidia.opendz.org ([98.142.220.152]:56276 "EHLO numidia.opendz.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750778Ab2ACB2r (ORCPT ); Mon, 2 Jan 2012 20:28:47 -0500 Content-Disposition: inline Sender: linux-ext4-owner@vger.kernel.org List-ID: The EXT{3,4}_IOC_SETVERSION ioctl() updates the inode without i_mutex, this can lead to a race with the other operations that update the same inode. Patch tested. Signed-off-by: Djalal Harouni --- fs/ext3/ioctl.c | 6 +++++- fs/ext4/ioctl.c | 6 +++++- 2 files changed, 10 insertions(+), 2 deletions(-) diff --git a/fs/ext3/ioctl.c b/fs/ext3/ioctl.c index ba1b54e..e7b2ed9 100644 --- a/fs/ext3/ioctl.c +++ b/fs/ext3/ioctl.c @@ -134,10 +134,11 @@ flags_out: goto setversion_out; } + mutex_lock(&inode->i_mutex); handle = ext3_journal_start(inode, 1); if (IS_ERR(handle)) { err = PTR_ERR(handle); - goto setversion_out; + goto unlock_out; } err = ext3_reserve_inode_write(handle, inode, &iloc); if (err == 0) { @@ -146,6 +147,9 @@ flags_out: err = ext3_mark_iloc_dirty(handle, inode, &iloc); } ext3_journal_stop(handle); + +unlock_out: + mutex_unlock(&inode->i_mutex); setversion_out: mnt_drop_write(filp->f_path.mnt); return err; diff --git a/fs/ext4/ioctl.c b/fs/ext4/ioctl.c index a567968..46a8de6 100644 --- a/fs/ext4/ioctl.c +++ b/fs/ext4/ioctl.c @@ -158,10 +158,11 @@ flags_out: goto setversion_out; } + mutex_lock(&inode->i_mutex); handle = ext4_journal_start(inode, 1); if (IS_ERR(handle)) { err = PTR_ERR(handle); - goto setversion_out; + goto unlock_out; } err = ext4_reserve_inode_write(handle, inode, &iloc); if (err == 0) { @@ -170,6 +171,9 @@ flags_out: err = ext4_mark_iloc_dirty(handle, inode, &iloc); } ext4_journal_stop(handle); + +unlock_out: + mutex_unlock(&inode->i_mutex); setversion_out: mnt_drop_write(filp->f_path.mnt); return err; -- 1.7.1