Commit e0c755a4 authored by George McCollister's avatar George McCollister Committed by David S. Miller
Browse files

net: dsa: don't assign an error value to tag_ops 



Use a temporary variable to hold the return value from
dsa_tag_driver_get() instead of assigning it to dst->tag_ops. Leaving
an error value in dst->tag_ops can result in deferencing an invalid
pointer when a deferred switch configuration happens later.

Fixes: 357f203b ("net: dsa: keep a copy of the tagging protocol in the DSA switch tree")

Signed-off-by: default avatarGeorge McCollister <george.mccollister@gmail.com>
Reviewed-by: default avatarVladimir Oltean <olteanv@gmail.com>
Reviewed-by: default avatarFlorian Fainelli <f.fainelli@gmail.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 8fb16e80

net/dsa/dsa2.c

+7 −4
Original line number Diff line number Diff line
@@ -1066,6 +1066,7 @@ static int dsa_port_parse_cpu(struct dsa_port *dp, struct net_device *master) 
{

	struct dsa_switch *ds = dp->ds;

	struct dsa_switch_tree *dst = ds->dst;

	const struct dsa_device_ops *tag_ops;

	enum dsa_tag_protocol tag_protocol;



	tag_protocol = dsa_get_tag_protocol(dp, master);
@@ -1080,14 +1081,16 @@ static int dsa_port_parse_cpu(struct dsa_port *dp, struct net_device *master) 
		 * nothing to do here.

		 */

	} else {

		dst->tag_ops = dsa_tag_driver_get(tag_protocol);

		if (IS_ERR(dst->tag_ops)) {

			if (PTR_ERR(dst->tag_ops) == -ENOPROTOOPT)

		tag_ops = dsa_tag_driver_get(tag_protocol);

		if (IS_ERR(tag_ops)) {

			if (PTR_ERR(tag_ops) == -ENOPROTOOPT)

				return -EPROBE_DEFER;

			dev_warn(ds->dev, "No tagger for this switch\n");

			dp->master = NULL;

			return PTR_ERR(dst->tag_ops);

			return PTR_ERR(tag_ops);

		}



		dst->tag_ops = tag_ops;

	}



	dp->master = master;