netdev - Re: [PATCH v4] net: don't call strlen on non-terminated string in dev_set

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]

Date:   Tue, 6 Jun 2017 23:57:35 +0200
From:   Florian Westphal <fw@...len.de>
To:     David Miller <davem@...emloft.net>
Cc:     glider@...gle.com, dvyukov@...gle.com, kcc@...gle.com,
        edumazet@...gle.com, stephen@...workplumber.org,
        linux-kernel@...r.kernel.org, netdev@...r.kernel.org
Subject: Re: [PATCH v4] net: don't call strlen on non-terminated string in
 dev_set_alias()

David Miller <davem@...emloft.net> wrote:
> From: Alexander Potapenko <glider@...gle.com>
> Date: Tue,  6 Jun 2017 15:56:54 +0200
> 
> > KMSAN reported a use of uninitialized memory in dev_set_alias(),
> > which was caused by calling strlcpy() (which in turn called strlen())
> > on the user-supplied non-terminated string.
> > 
> > Signed-off-by: Alexander Potapenko <glider@...gle.com>
> 
> We should not be allowing non-NULL terminated strings for the
> IFLA_IFALIAS attribute.  It's defined as type NLA_STRING in
> the ifla_policy[] array.

Unfortunately NLA_STRING doesn't check for NUL byte, only
NLA_NUL_STRING does this.

So unless you think we can change kernel and make NLA_STRING
behave like NLA_NUL_STRING I think patch is correct.