From 5e9a0fe492f89ff1c7583ee6ea89dc37b8c2e5c2 Mon Sep 17 00:00:00 2001 From: Jianbo Liu Date: Mon, 9 Jul 2018 02:26:20 +0000 Subject: [PATCH] net/sched: flower: Fix null pointer dereference when run tc vlan command Zahari issued tc vlan command without setting vlan_ethtype, which will crash kernel. To avoid this, we must check tb[TCA_FLOWER_KEY_VLAN_ETH_TYPE] is not null before use it. Also we don't need to dump vlan_ethtype or cvlan_ethtype in this case. Fixes: d64efd0926ba ('net/sched: flower: Add supprt for matching on QinQ vlan headers') Signed-off-by: Jianbo Liu Reported-by: Zahari Doychev Signed-off-by: David S. Miller --- net/sched/cls_flower.c | 48 +++++++++++++++++++++++------------------- 1 file changed, 26 insertions(+), 22 deletions(-) diff --git a/net/sched/cls_flower.c b/net/sched/cls_flower.c index 487a152a852c..8b2474293db1 100644 --- a/net/sched/cls_flower.c +++ b/net/sched/cls_flower.c @@ -605,20 +605,22 @@ static int fl_set_key(struct net *net, struct nlattr **tb, TCA_FLOWER_KEY_VLAN_PRIO, &key->vlan, &mask->vlan); - ethertype = nla_get_be16(tb[TCA_FLOWER_KEY_VLAN_ETH_TYPE]); - if (eth_type_vlan(ethertype)) { - fl_set_key_vlan(tb, ethertype, - TCA_FLOWER_KEY_CVLAN_ID, - TCA_FLOWER_KEY_CVLAN_PRIO, - &key->cvlan, &mask->cvlan); - fl_set_key_val(tb, &key->basic.n_proto, - TCA_FLOWER_KEY_CVLAN_ETH_TYPE, - &mask->basic.n_proto, - TCA_FLOWER_UNSPEC, - sizeof(key->basic.n_proto)); - } else { - key->basic.n_proto = ethertype; - mask->basic.n_proto = cpu_to_be16(~0); + if (tb[TCA_FLOWER_KEY_VLAN_ETH_TYPE]) { + ethertype = nla_get_be16(tb[TCA_FLOWER_KEY_VLAN_ETH_TYPE]); + if (eth_type_vlan(ethertype)) { + fl_set_key_vlan(tb, ethertype, + TCA_FLOWER_KEY_CVLAN_ID, + TCA_FLOWER_KEY_CVLAN_PRIO, + &key->cvlan, &mask->cvlan); + fl_set_key_val(tb, &key->basic.n_proto, + TCA_FLOWER_KEY_CVLAN_ETH_TYPE, + &mask->basic.n_proto, + TCA_FLOWER_UNSPEC, + sizeof(key->basic.n_proto)); + } else { + key->basic.n_proto = ethertype; + mask->basic.n_proto = cpu_to_be16(~0); + } } } else { key->basic.n_proto = ethertype; @@ -1344,14 +1346,16 @@ static int fl_dump(struct net *net, struct tcf_proto *tp, void *fh, key->cvlan.vlan_tpid))) goto nla_put_failure; - if (mask->cvlan.vlan_tpid) { - if (nla_put_be16(skb, TCA_FLOWER_KEY_CVLAN_ETH_TYPE, - key->basic.n_proto)) - goto nla_put_failure; - } else if (mask->vlan.vlan_tpid) { - if (nla_put_be16(skb, TCA_FLOWER_KEY_VLAN_ETH_TYPE, - key->basic.n_proto)) - goto nla_put_failure; + if (mask->basic.n_proto) { + if (mask->cvlan.vlan_tpid) { + if (nla_put_be16(skb, TCA_FLOWER_KEY_CVLAN_ETH_TYPE, + key->basic.n_proto)) + goto nla_put_failure; + } else if (mask->vlan.vlan_tpid) { + if (nla_put_be16(skb, TCA_FLOWER_KEY_VLAN_ETH_TYPE, + key->basic.n_proto)) + goto nla_put_failure; + } } if ((key->basic.n_proto == htons(ETH_P_IP) || -- 2.30.2