netdev - Re: Fwd: Possible bug in net/ipv4/route.c?

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: <1278361087.2466.107.camel@edumazet-laptop>
Date:	Mon, 05 Jul 2010 22:18:07 +0200
From:	Eric Dumazet <eric.dumazet@...il.com>
To:	Henrique de Moraes Holschuh <hmh@....eng.br>
Cc:	Herbert Xu <herbert@...dor.apana.org.au>, yoshfuji@...ux-ipv6.org,
	netdev@...r.kernel.org, linux-kernel@...r.kernel.org,
	Stephen Hemminger <shemminger@...tta.com>
Subject: Re: Fwd: Possible bug in net/ipv4/route.c?

Le lundi 05 juillet 2010 à 17:07 -0300, Henrique de Moraes Holschuh a
écrit :
> On Mon, 05 Jul 2010, Eric Dumazet wrote:
> > Le lundi 05 juillet 2010 à 21:22 +0800, Herbert Xu a écrit :
> > > On Mon, Jul 05, 2010 at 02:59:14PM +0200, Eric Dumazet wrote:
> > > >
> > > > Why do we clear full 48 bytes skb->cb[] in skb_alloc(), if no protocol
> > > > stack should rely it being zero ?
> > > 
> > > Unless a protocol is allocating the skb itself, then the fact
> > > that skb_alloc clears skb->cb is no guarantee that the skb->cb
> > > will be zero.
> > 
> > I see. We could :
> > 
> > Avoid this memset(skb->cb, 0, sizeof(skb->cb)) in fastpath.
> 
> Any chances of skb->cb being leaked to userspace or the network, due to
> driver bugs or other such oddities?
> 

Not "a priori", but a bug is always possible ;)

cb[] is internal use only, should not be sent to network or user land.



--
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