From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.kernel.org ([198.145.29.99]:44750 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2388749AbeKLIUa (ORCPT ); Mon, 12 Nov 2018 03:20:30 -0500 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, syzbot+c61979f6f2cba5cb3c06@syzkaller.appspotmail.com, Theodore Tso , stable@kernel.org, Sasha Levin Subject: [PATCH 4.18 162/350] ext4: fix argument checking in EXT4_IOC_MOVE_EXT Date: Sun, 11 Nov 2018 14:20:26 -0800 Message-Id: <20181111221714.825189705@linuxfoundation.org> In-Reply-To: <20181111221707.043394111@linuxfoundation.org> References: <20181111221707.043394111@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org List-ID: 4.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Theodore Ts'o [ Upstream commit f18b2b83a727a3db208308057d2c7945f368e625 ] If the starting block number of either the source or destination file exceeds the EOF, EXT4_IOC_MOVE_EXT should return EINVAL. Also fixed the helper function mext_check_coverage() so that if the logical block is beyond EOF, make it return immediately, instead of looping until the block number wraps all the away around. This takes long enough that if there are multiple threads trying to do pound on an the same inode doing non-sensical things, it can end up triggering the kernel's soft lockup detector. Reported-by: syzbot+c61979f6f2cba5cb3c06@syzkaller.appspotmail.com Signed-off-by: Theodore Ts'o Cc: stable@kernel.org Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- fs/ext4/move_extent.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) --- a/fs/ext4/move_extent.c +++ b/fs/ext4/move_extent.c @@ -518,9 +518,13 @@ mext_check_arguments(struct inode *orig_ orig_inode->i_ino, donor_inode->i_ino); return -EINVAL; } - if (orig_eof < orig_start + *len - 1) + if (orig_eof <= orig_start) + *len = 0; + else if (orig_eof < orig_start + *len - 1) *len = orig_eof - orig_start; - if (donor_eof < donor_start + *len - 1) + if (donor_eof <= donor_start) + *len = 0; + else if (donor_eof < donor_start + *len - 1) *len = donor_eof - donor_start; if (!*len) { ext4_debug("ext4 move extent: len should not be 0 "