From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from bombadil.infradead.org ([198.137.202.133]:45718 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751516AbeFFK6V (ORCPT ); Wed, 6 Jun 2018 06:58:21 -0400 Date: Wed, 6 Jun 2018 03:58:17 -0700 From: Christoph Hellwig Subject: Re: [PATCH V2] xfs: fix string handling in get/set functions Message-ID: <20180606105817.GA6575@infradead.org> References: <20180525151421.2317292-1-arnd@arndb.de> <7aad9fc3-ed65-a016-d477-5d830e31cb43@sandeen.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <7aad9fc3-ed65-a016-d477-5d830e31cb43@sandeen.net> Sender: linux-xfs-owner@vger.kernel.org List-ID: List-Id: xfs To: Eric Sandeen Cc: Arnd Bergmann , "Darrick J. Wong" , linux-xfs@vger.kernel.org, Eric Sandeen , Martin Sebor , Brian Foster , Dave Chinner , Dan Williams , Ross Zwisler , linux-kernel@vger.kernel.org > diff --git a/fs/xfs/xfs_ioctl.c b/fs/xfs/xfs_ioctl.c > index 82f7c83c1dad..596e176c19a6 100644 > --- a/fs/xfs/xfs_ioctl.c > +++ b/fs/xfs/xfs_ioctl.c > @@ -1828,13 +1828,13 @@ xfs_ioc_getlabel( > /* Paranoia */ > BUILD_BUG_ON(sizeof(sbp->sb_fname) > FSLABEL_MAX); > > + /* 1 larger than sb_fname, so this ensures a trailing NUL char */ > + memset(label, 0, sizeof(label)); I don't get the comment. In fact I don't even get why we need any comment here. This is a structure that gets copied to userspace, and we zero the whole structure, as we should do by default for anything that goes to userspace. Otherwise this looks fine to me.