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: 357f203bb3b5 ("net: dsa: keep a copy of the tagging protocol in the DSA switch tree")
Signed-off-by: George McCollister <george.mccollister@gmail.com>
Reviewed-by: Vladimir Oltean <olteanv@gmail.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/dsa/dsa2.c b/net/dsa/dsa2.c
index 4d4956e..d142eb2 100644
--- a/net/dsa/dsa2.c
+++ b/net/dsa/dsa2.c
@@ -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;