netdev - Re: [PATCH 2/7] CAN: Add PF

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: <46F3BD75.6010904@trash.net>
Date:	Fri, 21 Sep 2007 14:47:49 +0200
From:	Patrick McHardy <kaber@...sh.net>
To:	Urs Thuermann <urs@...ogud.escape.de>
CC:	netdev@...r.kernel.org, David Miller <davem@...emloft.net>,
	Thomas Gleixner <tglx@...utronix.de>,
	Oliver Hartkopp <oliver@...tkopp.net>,
	Oliver Hartkopp <oliver.hartkopp@...kswagen.de>,
	Urs Thuermann <urs.thuermann@...kswagen.de>
Subject: Re: [PATCH 2/7] CAN: Add PF_CAN core module

Urs Thuermann wrote:
> +static int can_create(struct net *net, struct socket *sock, int protocol)
> +{
> +	...
> +
> +	spin_lock(&proto_tab_lock);
> +	cp = proto_tab[protocol];
> +	if (cp && !try_module_get(cp->prot->owner))
> +		cp = NULL;
> +	spin_unlock(&proto_tab_lock);
> +
> +	/* check for success and correct type */
> +	if (!cp || cp->type != sock->type) {
> +		ret = -EPROTONOSUPPORT;
> +		goto errout;
> +	}
> +
> +	if (cp->capability >= 0 && !capable(cp->capability)) {
> +		ret = -EPERM;
> +		goto errout;
> +	}
> +
> +	sock->ops = cp->ops;


You drop the module reference again when leaving this function.
So sock->ops might contain a stale pointer if the module is
unloaded after this. You need to either keep the module reference
while the socket is alive or remove stale references when
unregistering the protocol.

-
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