netdev - Re: [SECURITY] CAN info leak/minor heap overflow

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]

Date:	Tue, 02 Nov 2010 15:53:25 -0400
From:	Dan Rosenberg <drosenberg@...curity.com>
To:	Oliver Hartkopp <socketcan@...tkopp.net>
Cc:	netdev@...r.kernel.org, security@...nel.org
Subject: Re: [SECURITY] CAN info leak/minor heap overflow


> 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 ...
> 

This is a bad idea because it makes exploiting other kernel
vulnerabilities easier.  Exposing the address of an object in a slab
cache, especially an object that unprivileged users have some level of
control of, is just an invitation to use that structure when writing
exploits, for heap overflows or otherwise.

-Dan

> > 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


--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html