From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S970050AbdAFKL2 (ORCPT ); Fri, 6 Jan 2017 05:11:28 -0500 Received: from mx2.suse.de ([195.135.220.15]:38017 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1761190AbdAFKK2 (ORCPT ); Fri, 6 Jan 2017 05:10:28 -0500 Date: Fri, 6 Jan 2017 11:10:25 +0100 From: Jan Kara To: Gu Zheng Cc: linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, viro@zeniv.linux.org.uk, jack@suse.cz Subject: Re: [PATCH] tmpfs: clear S_ISGID when setting posix ACLs Message-ID: <20170106101025.GA3533@quack2.suse.cz> References: <1483690375-40718-1-git-send-email-guzheng1@huawei.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1483690375-40718-1-git-send-email-guzheng1@huawei.com> User-Agent: Mutt/1.5.24 (2015-08-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri 06-01-17 16:12:55, Gu Zheng wrote: > This change was missed the tmpfs modification in In CVE-2016-7097 > commit 073931017b49d9458aa351605b43a7e34598caef > posix_acl: Clear SGID bit when setting file permissions. > It can test by xfstest generic/375, which failed to clear > setgid bit in the following test case on tmpfs: > > touch $testfile > chown 100:100 $testfile > chmod 2755 $testfile > _runas -u 100 -g 101 -- setfacl -m u::rwx,g::rwx,o::rwx $testfile > > Signed-off-by: Gu Zheng Ah, good catch. One comment below: > diff --git a/fs/posix_acl.c b/fs/posix_acl.c > index 5955220..d014dff 100644 > --- a/fs/posix_acl.c > +++ b/fs/posix_acl.c > @@ -922,11 +922,10 @@ int simple_set_acl(struct inode *inode, struct posix_acl *acl, int type) > int error; > > if (type == ACL_TYPE_ACCESS) { > - error = posix_acl_equiv_mode(acl, &inode->i_mode); > - if (error < 0) > - return 0; > - if (error == 0) > - acl = NULL; > + error = posix_acl_update_mode(inode, > + &inode->i_mode, &acl); > + if (error > 0) > + return error; Uh, why this error > 0 check? AFAIU it should be: if (error < 0) return 0; As it used to be before... Honza -- Jan Kara SUSE Labs, CR