linux-kernel - Re: file system permissions regression affecting root

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] [day] [month] [year] [list]

Date:   Sat, 16 May 2020 21:47:38 -0700 (PDT)
From:   Christian Kujau <lists@...dbynature.de>
To:     Patrick Donnelly <batrick@...bytes.com>
cc:     Al Viro <viro@...iv.linux.org.uk>,
        open list <linux-kernel@...r.kernel.org>,
        Jeff Layton <jlayton@...hat.com>, xiubli@...hat.com,
        kchai@...hat.com
Subject: Re: file system permissions regression affecting root

On Wed, 13 May 2020, Patrick Donnelly wrote:
> However, it seems odd that this depends on the owner of the directory.
> i.e. this protection only seems to be enforced if the sticky directory
> is owned by root. That's expected?

According to the documentation[0] this appears to be intentional:

 protected_regular:
   [...]
   When set to "1" don't allow O_CREAT open on regular files that we
   don't own in world writable sticky directories, unless they are
   owned by the owner of the directory.

C.

[0] https://www.kernel.org/doc/Documentation/sysctl/fs.txt
-- 
BOFH excuse #263:

It's stuck in the Web.