linux-ext4 - Re: [PATCH v2] fs/{posix_acl,ext2,jfs,ceph}: apply umask if ACL support is disabled

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20231011135922.4bij3ittlg4ujkd7@quack3>
Date:   Wed, 11 Oct 2023 15:59:22 +0200
From:   Jan Kara <jack@...e.cz>
To:     Max Kellermann <max.kellermann@...os.com>
Cc:     Jan Kara <jack@...e.cz>, Xiubo Li <xiubli@...hat.com>,
        Ilya Dryomov <idryomov@...il.com>,
        Jeff Layton <jlayton@...nel.org>, Jan Kara <jack@...e.com>,
        Dave Kleikamp <shaggy@...nel.org>, ceph-devel@...r.kernel.org,
        linux-kernel@...r.kernel.org, linux-ext4@...r.kernel.org,
        jfs-discussion@...ts.sourceforge.net,
        Christian Brauner <brauner@...nel.org>,
        Yang Xu <xuyang2018.jy@...itsu.com>,
        linux-fsdevel@...r.kernel.org
Subject: Re: [PATCH v2] fs/{posix_acl,ext2,jfs,ceph}: apply umask if ACL
 support is disabled

On Wed 11-10-23 14:27:49, Max Kellermann wrote:
> On Wed, Oct 11, 2023 at 2:18 PM Max Kellermann <max.kellermann@...os.com> wrote:
> > But without the other filesystems. I'll resend it with just the
> > posix_acl.h hunk.
> 
> Thinking again, I don't think this is the proper solution. This may
> server as a workaround so those broken filesystems don't suffer from
> this bug, but it's not proper.
> 
> posix_acl_create() is only supposed to appy the umask if the inode
> supports ACLs; if not, the VFS is supposed to do it. But if the
> filesystem pretends to have ACL support but the kernel does not, it's
> really a filesystem bug. Hacking the umask code into
> posix_acl_create() for that inconsistent case doesn't sound right.
> 
> A better workaround would be this patch:
> https://patchwork.kernel.org/project/linux-nfs/patch/151603744662.29035.4910161264124875658.stgit@rabbit.intern.cm-ag/
> I submitted it more than 5 years ago, it got one positive review, but
> was never merged.
> 
> This patch enables the VFS's umask code even if the filesystem
> prerents to support ACLs. This still doesn't fix the filesystem bug,
> but makes VFS's behavior consistent.

OK, that solution works for me as well. I agree it seems a tad bit cleaner.
Christian, which one would you prefer?

								Honza
-- 
Jan Kara <jack@...e.com>
SUSE Labs, CR