linux-kernel - Re: Leaking path for search_binary

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]

Message-ID: <e36e7259-5cf8-3c5b-98d3-5c4d5c4b82b1@tycho.nsa.gov>
Date:   Wed, 26 Sep 2018 08:59:38 -0400
From:   Stephen Smalley <sds@...ho.nsa.gov>
To:     Tong Zhang <ztong@...edu>
Cc:     linux-fsdevel@...r.kernel.org, linux-kernel@...r.kernel.org,
        linux-security-module@...r.kernel.org, wenbo.s@...sung.com
Subject: Re: Leaking path for search_binary_handler

On 09/25/2018 01:27 PM, Tong Zhang wrote:
> Kernel Version: 4.18.5
> 
> Problem Description:
> 
> search_binary_handler() should be called after setting bprm using prepare_binprm(),
> and in prepare_binprm(), there’s a LSM hook security_bprm_set_creds(),
> which can make a decision that binfmt cares.
> 
> We found a leaking path In fs/binfmt_misc.c:235, that don’t ask LSM’s decision.

Do you mean the MISC_FMT_CREDENTIALS case? That looks intentional to me, 
as noted in the comment there, and as per 
Documentation/admin-guide/binfmt-misc.rst's discussion of the 
credentials flag.