netdev - Re: gianfar.c null pointer deref in gfar_start

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: <20110809130615.GT4926@sgi.com>
Date:	Tue, 9 Aug 2011 08:06:15 -0500
From:	Robin Holt <holt@....com>
To:	Eric Dumazet <eric.dumazet@...il.com>
Cc:	Robin Holt <holt@....com>,
	Sandeep Gopalpet <Sandeep.Kumar@...escale.com>,
	"David S. Miller" <davem@...emloft.net>, netdev@...r.kernel.org
Subject: Re: gianfar.c null pointer deref in gfar_start_xmit().

On Tue, Aug 09, 2011 at 09:10:13AM +0200, Eric Dumazet wrote:
> Le mardi 09 août 2011 à 01:54 -0500, Robin Holt a écrit :
> > On Tue, Aug 02, 2011 at 09:44:38PM -0500, Robin Holt wrote:
> > > 
> > > While using the v3.0 kernel on a Freescale P1010RDB with 3 minor patches
> > > (None which affect gianfar.c), I get a NULL pointer deref at:
> > > 
> > > static int gfar_start_xmit(struct sk_buff *skb, struct net_device *dev)
> > > {
> > > ...
> > > 	regs = tx_queue->grp->regs;
> > > 
> > > I put a BUG_ON(tx_queue->grp) just before this line and it did trip.
> > > I have not looked at this any more than that.
> > > 
> > > Any suggestions would be welcome.   To reproduce, all I need to do is
> > > a few sequences of pings.
> > 
> > I was able to reproduce this with the net-next-2.6 kernel as well.
> > 
> 
> This driver incorrectly assumes a non dense txqueue array is possible
> for a netdev, but its not true.
> 
> In the meantime, you could force it to use one tx_queue only.
> 
> tx_queues = (u32 *)of_get_property(np, "fsl,num_tx_queues", NULL);
> num_tx_qs = tx_queues ? *tx_queues : 1;

I fixed up the .dts file and now it works.  I have not tested the RGMII
interface yet so I do not know if that supports multiple queues.  I assume
I could find it in the documentation.  What might I be looking for?

Thanks,
Robin
--
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