linux-kernel - Re: PATCH? net/bridge/br_if.c: fix use after free in port_carrier

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]

Date:	Tue, 20 Feb 2007 17:34:12 +0300
From:	Oleg Nesterov <oleg@...sign.ru>
To:	David Howells <dhowells@...hat.com>
Cc:	Andrew Morton <akpm@...ux-foundation.org>,
	Jarek Poplawski <jarkao2@...pl>,
	"David S. Miller" <davem@...emloft.net>,
	linux-kernel@...r.kernel.org
Subject: Re: PATCH? net/bridge/br_if.c: fix use after free in port_carrier_check()

On 02/20, David Howells wrote:
> 
> Oleg Nesterov <oleg@...sign.ru> wrote:
> 
> >  static void release_nbp(struct kobject *kobj)
> >  {
> >  	struct net_bridge_port *p
> >  		= container_of(kobj, struct net_bridge_port, kobj);
> > +
> > +	dev_put(p->dev);
> 
> Does this need to be done with the mutex held?

I think no. At least the current code does dev_put() without mutex held.

>                                                     And does anything actually pay
> attention to the refcount on dev?  I assume not...

I guess net/core/dev.c:netdev_wait_allrefs(), but not sure.

> Should you clear p->dev->br_port before calling dev_put()?

Looks like it is protected by RCU... Anyway the current code does the same.

> Looks reasonable.  I like it.
> 
> Acked-By: David Howells <dhowells@...hat.com>

Thanks! I'll re-send with a proper changelog later today.

Oleg.

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/