netdev - Re: [PATCH] rionet: Don't try to corrupt skbuff assigning data pointer directly

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]

Message-ID: <559638AB.9010707@nokia.com>
Date:	Fri, 3 Jul 2015 09:24:27 +0200
From:	Alexander Sverdlin <alexander.sverdlin@...ia.com>
To:	ext David Miller <davem@...emloft.net>
Cc:	netdev@...r.kernel.org, mporter@...nel.crashing.org,
	alexandre.bounine@....com, frank.kunz@...ia.com,
	marek.krzyzowski@...ia.com
Subject: Re: [PATCH] rionet: Don't try to corrupt skbuff assigning data
 pointer directly

Hi David,

On 02/07/15 21:12, ext David Miller wrote:
>> It's not allowed to assign data pointer of skbuff directly, this makes no sense
>> > if the assigned pointer is the very same as already existing one, or it brakes
>> > all the pointer arithmetics in all other cases. We cannot do better as just
>> > compare them and report BUG() in case of mismatch.
>> > 
>> > Signed-off-by: Alexander Sverdlin <alexander.sverdlin@...ia.com>
> BUG takes the entire machine out, which is worse than corrupting the
> skb->data
> 
> If you really want to assert this condition, do it in a way that
> doesn't kill the entire machine.

In fact, the machine goes down, some milliseconds later, but because of the following
inconsistencies, which are misleading. The function has no way to signal an error and
this line of code is simply wrong. To prevent others from copying this error, we can
simply delete it. Would it be fine from your PoV?

-- 
Best regards,
Alexander Sverdlin.
--
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