From 2ff4a0243c9e7b16c4fa1e9b7ab08525f4b11a40 Mon Sep 17 00:00:00 2001 From: Florian Fainelli Date: Mon, 9 Jan 2017 11:58:34 -0800 Subject: net: dsa: Ensure validity of dst->ds[0] [ Upstream commit faf3a932fbeb77860226a8323eacb835edc98648 ] It is perfectly possible to have non zero indexed switches being present in a DSA switch tree, in such a case, we will be deferencing a NULL pointer while dsa_cpu_port_ethtool_{setup,restore}. Be more defensive and ensure that dst->ds[0] is valid before doing anything with it. Fixes: 0c73c523cf73 ("net: dsa: Initialize CPU port ethtool ops per tree") Signed-off-by: Florian Fainelli Reviewed-by: Vivien Didelot Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/dsa/dsa2.c | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-) (limited to 'net/dsa') diff --git a/net/dsa/dsa2.c b/net/dsa/dsa2.c index 5fff951a0a49..da3862124545 100644 --- a/net/dsa/dsa2.c +++ b/net/dsa/dsa2.c @@ -394,9 +394,11 @@ static int dsa_dst_apply(struct dsa_switch_tree *dst) return err; } - err = dsa_cpu_port_ethtool_setup(dst->ds[0]); - if (err) - return err; + if (dst->ds[0]) { + err = dsa_cpu_port_ethtool_setup(dst->ds[0]); + if (err) + return err; + } /* If we use a tagging format that doesn't have an ethertype * field, make sure that all packets from this point on get @@ -433,7 +435,8 @@ static void dsa_dst_unapply(struct dsa_switch_tree *dst) dsa_ds_unapply(dst, ds); } - dsa_cpu_port_ethtool_restore(dst->ds[0]); + if (dst->ds[0]) + dsa_cpu_port_ethtool_restore(dst->ds[0]); pr_info("DSA: tree %d unapplied\n", dst->tree); dst->applied = false; -- cgit v1.2.3