linux-kernel - 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] [day] [month] [year] [list]

Message-Id: <20170606.210427.2001413617170270195.davem@davemloft.net>
Date:   Tue, 06 Jun 2017 21:04:27 -0400 (EDT)
From:   David Miller <davem@...emloft.net>
To:     fw@...len.de
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()

From: Florian Westphal <fw@...len.de>
Date: Tue, 6 Jun 2017 23:57:35 +0200

> 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.

Ok, I missed that, thanks for the clarification.

I'll apply this and queue it up for -stable, thanks.