linux-kernel - Re: KASAN: slab-out-of-bounds Read in strcmp

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 for Android: free password hash cracker in your pocket

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

Message-ID: <alpine.LFD.2.20.1712041150270.1348@localhost>
Date:   Mon, 4 Dec 2017 11:51:55 +1100 (AEDT)
From:   James Morris <james.l.morris@...cle.com>
To:     Tetsuo Handa <penguin-kernel@...ove.SAKURA.ne.jp>
cc:     bot+015afdb01dbf2abb6a6bfdd5430b72e5503fca6d@...kaller.appspotmail.com,
        linux-security-module@...r.kernel.org, selinux@...ho.nsa.gov,
        syzkaller-bugs@...glegroups.com, danielj@...lanox.com,
        dledford@...hat.com, eparis@...isplace.org, junil0814.lee@....com,
        kyeongdon.kim@....com, linux-kernel@...r.kernel.org,
        mka@...omium.org, paul@...l-moore.com, sds@...ho.nsa.gov,
        serge@...lyn.com
Subject: Re: KASAN: slab-out-of-bounds Read in strcmp

On Sun, 3 Dec 2017, Tetsuo Handa wrote:

> Tetsuo Handa wrote:
> > which will allow strcmp() to trigger out of bound read when "size" is
> > larger than strlen(initial_sid_to_string[i]).
> 
> Oops. "smaller" than.
> 
> > 
> > Thus, I guess the simplest fix is to use strncmp() instead of strcmp().
> 
> Can somebody test below patch? (My CentOS 7 environment does not support
> enabling SELinux in linux.git . Userspace tool is too old to support?)

You mean enabling KASAN?  Yep, you need gcc 4.9.2 or better.  Recent 
Fedora has it.


-- 
James Morris
<james.l.morris@...cle.com>