From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752169AbcFPHH1 (ORCPT ); Thu, 16 Jun 2016 03:07:27 -0400 Received: from userp1040.oracle.com ([156.151.31.81]:19467 "EHLO userp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751246AbcFPHH0 (ORCPT ); Thu, 16 Jun 2016 03:07:26 -0400 Date: Thu, 16 Jun 2016 10:07:09 +0300 From: Dan Carpenter To: "Theodore Ts'o" Cc: Andreas Dilger , linux-ext4@vger.kernel.org, linux-kernel@vger.kernel.org, kernel-janitors@vger.kernel.org Subject: [patch] ext4: underflow in alignment check Message-ID: <20160616070709.GC23129@mwanda> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.6.0 (2016-04-01) X-Source-IP: aserv0021.oracle.com [141.146.126.233] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org My static checker complains that this can underflow if arg is negative which is true. Signed-off-by: Dan Carpenter diff --git a/fs/ext4/super.c b/fs/ext4/super.c index b1a3471..a2a17e9 100644 --- a/fs/ext4/super.c +++ b/fs/ext4/super.c @@ -1576,7 +1576,7 @@ static int handle_mount_opt(struct super_block *sb, char *opt, int token, } else if (token == Opt_min_batch_time) { sbi->s_min_batch_time = arg; } else if (token == Opt_inode_readahead_blks) { - if (arg && (arg > (1 << 30) || !is_power_of_2(arg))) { + if (arg && (arg > (1U << 30) || !is_power_of_2(arg))) { ext4_msg(sb, KERN_ERR, "EXT4-fs: inode_readahead_blks must be " "0 or a power of 2 smaller than 2^31");