From: Oliver Hartkopp <socketcan@hartkopp.net>
To: Dan Rosenberg <drosenberg@vsecurity.com>
Cc: urs.thuermann@volkswagen.de, netdev@vger.kernel.org, security@kernel.org
Subject: Re: [SECURITY] CAN info leak/minor heap overflow
Date: Tue, 02 Nov 2010 20:43:16 +0100 [thread overview]
Message-ID: <4CD069D4.7010801@hartkopp.net> (raw)
In-Reply-To: <1288722503.2504.14.camel@dan>
Hello Dan,
On 02.11.2010 19:28, Dan Rosenberg wrote:
> In bcm_connect() (in net/can/bcm.c), I noticed the following code:
>
> sprintf(bo->procname, "%p", sock);
>
> "procname" is a 9-byte char array. This code is wrong on two levels.
> First, leaking a kernel address via a /proc filename is bad.
Why is this bad? Can the addresses of CAN-BCM sock structs be used for
anything from userspace?
For me they are just intented to be unique numbers ...
> Secondly,
> on 64-bit platforms, up to 17 bytes may be copied into the buffer.
Hm - that's indeed not wanted. Will send a patch at least for this issue.
> Fortunately, structure padding will most likely prevent this from being
> a problem, except for the trailing NULL byte, which may overwrite the
> first byte of the next heap object. Please name your procfile in a way
> that doesn't leak information and fits into the desired name buffer.
>
> -Dan
>
Regards,
Oliver
next prev parent reply other threads:[~2010-11-02 19:43 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-11-02 18:28 [SECURITY] CAN info leak/minor heap overflow Dan Rosenberg
2010-11-02 19:43 ` Oliver Hartkopp [this message]
2010-11-02 19:53 ` Dan Rosenberg
2010-11-02 19:57 ` [Security] " Linus Torvalds
2010-11-02 20:19 ` Oliver Hartkopp
2010-11-02 20:16 ` Oliver Hartkopp
2010-11-05 18:33 ` [PATCH] Fix " Urs Thuermann
2010-11-09 7:52 ` Oliver Hartkopp
2010-11-09 17:05 ` David Miller
2010-11-10 6:52 ` Oliver Hartkopp
2010-11-10 17:51 ` David Miller
2010-11-10 22:10 ` Oliver Hartkopp
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