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]
Date:   Thu, 10 Mar 2022 17:07:17 +0200
From:   Vladimir Oltean <olteanv@...il.com>
To:     Hans Schultz <schultz.hans@...il.com>
Cc:     davem@...emloft.net, kuba@...nel.org, netdev@...r.kernel.org,
        Andrew Lunn <andrew@...n.ch>,
        Vivien Didelot <vivien.didelot@...il.com>,
        Florian Fainelli <f.fainelli@...il.com>,
        Jiri Pirko <jiri@...nulli.us>,
        Ivan Vecera <ivecera@...hat.com>,
        Roopa Prabhu <roopa@...dia.com>,
        Nikolay Aleksandrov <razor@...ckwall.org>,
        Daniel Borkmann <daniel@...earbox.net>,
        Ido Schimmel <idosch@...dia.com>, linux-kernel@...r.kernel.org,
        bridge@...ts.linux-foundation.org
Subject: Re: [PATCH net-next 3/3] net: dsa: mv88e6xxx: mac-auth/MAB
 implementation

On Thu, Mar 10, 2022 at 04:00:52PM +0100, Hans Schultz wrote:
> >> +	brport = dsa_port_to_bridge_port(dp);
> >
> > Since this is threaded interrupt context, I suppose it could race with
> > dsa_port_bridge_leave(). So it is best to check whether "brport" is NULL
> > or not.
> >
> Would something like:
> if (dsa_is_unused_port(chip->ds, port))
>         return -ENODATA;
> 
> be appropriate and sufficient for that?

static inline
struct net_device *dsa_port_to_bridge_port(const struct dsa_port *dp)
{
	if (!dp->bridge)
		return NULL;

	if (dp->lag)
		return dp->lag->dev;
	else if (dp->hsr_dev)
		return dp->hsr_dev;

	return dp->slave;
}

Notice the "dp->bridge" check. The assignments are in dsa_port_bridge_create()
and in dsa_port_bridge_destroy(). These functions assume rtnl_mutex protection.
The question was how do you serialize with that, and why do you assume
that dsa_port_to_bridge_port() returns non-NULL.

So no, dsa_is_unused_port() would do absolutely nothing to help.

Powered by blists - more mailing lists