From: Maxim Mikityanskiy maximmi@mellanox.com
[ Upstream commit 405b93eb764367a670e729da18e54dc42db32620 ]
The current ARFS code relies on certain fields to be set in the SKB (e.g. transport_header) and extracts IP addresses and ports by custom code that parses the packet. The necessary SKB fields, however, are not always set at that point, which leads to an out-of-bounds access. Use skb_flow_dissect_flow_keys() to get the necessary information reliably, fix the out-of-bounds access and reuse the code.
Fixes: 18c908e477dc ("net/mlx5e: Add accelerated RFS support") Signed-off-by: Maxim Mikityanskiy maximmi@mellanox.com Reviewed-by: Tariq Toukan tariqt@mellanox.com Signed-off-by: Saeed Mahameed saeedm@mellanox.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/net/ethernet/mellanox/mlx5/core/en_arfs.c | 97 +++++++--------------- 1 file changed, 34 insertions(+), 63 deletions(-)
--- a/drivers/net/ethernet/mellanox/mlx5/core/en_arfs.c +++ b/drivers/net/ethernet/mellanox/mlx5/core/en_arfs.c @@ -439,12 +439,6 @@ arfs_hash_bucket(struct arfs_table *arfs return &arfs_t->rules_hash[bucket_idx]; }
-static u8 arfs_get_ip_proto(const struct sk_buff *skb) -{ - return (skb->protocol == htons(ETH_P_IP)) ? - ip_hdr(skb)->protocol : ipv6_hdr(skb)->nexthdr; -} - static struct arfs_table *arfs_get_table(struct mlx5e_arfs_tables *arfs, u8 ip_proto, __be16 etype) { @@ -601,31 +595,9 @@ out: arfs_may_expire_flow(priv); }
-/* return L4 destination port from ip4/6 packets */ -static __be16 arfs_get_dst_port(const struct sk_buff *skb) -{ - char *transport_header; - - transport_header = skb_transport_header(skb); - if (arfs_get_ip_proto(skb) == IPPROTO_TCP) - return ((struct tcphdr *)transport_header)->dest; - return ((struct udphdr *)transport_header)->dest; -} - -/* return L4 source port from ip4/6 packets */ -static __be16 arfs_get_src_port(const struct sk_buff *skb) -{ - char *transport_header; - - transport_header = skb_transport_header(skb); - if (arfs_get_ip_proto(skb) == IPPROTO_TCP) - return ((struct tcphdr *)transport_header)->source; - return ((struct udphdr *)transport_header)->source; -} - static struct arfs_rule *arfs_alloc_rule(struct mlx5e_priv *priv, struct arfs_table *arfs_t, - const struct sk_buff *skb, + const struct flow_keys *fk, u16 rxq, u32 flow_id) { struct arfs_rule *rule; @@ -640,19 +612,19 @@ static struct arfs_rule *arfs_alloc_rule INIT_WORK(&rule->arfs_work, arfs_handle_work);
tuple = &rule->tuple; - tuple->etype = skb->protocol; + tuple->etype = fk->basic.n_proto; + tuple->ip_proto = fk->basic.ip_proto; if (tuple->etype == htons(ETH_P_IP)) { - tuple->src_ipv4 = ip_hdr(skb)->saddr; - tuple->dst_ipv4 = ip_hdr(skb)->daddr; + tuple->src_ipv4 = fk->addrs.v4addrs.src; + tuple->dst_ipv4 = fk->addrs.v4addrs.dst; } else { - memcpy(&tuple->src_ipv6, &ipv6_hdr(skb)->saddr, + memcpy(&tuple->src_ipv6, &fk->addrs.v6addrs.src, sizeof(struct in6_addr)); - memcpy(&tuple->dst_ipv6, &ipv6_hdr(skb)->daddr, + memcpy(&tuple->dst_ipv6, &fk->addrs.v6addrs.dst, sizeof(struct in6_addr)); } - tuple->ip_proto = arfs_get_ip_proto(skb); - tuple->src_port = arfs_get_src_port(skb); - tuple->dst_port = arfs_get_dst_port(skb); + tuple->src_port = fk->ports.src; + tuple->dst_port = fk->ports.dst;
rule->flow_id = flow_id; rule->filter_id = priv->fs.arfs.last_filter_id++ % RPS_NO_FILTER; @@ -663,37 +635,33 @@ static struct arfs_rule *arfs_alloc_rule return rule; }
-static bool arfs_cmp_ips(struct arfs_tuple *tuple, - const struct sk_buff *skb) +static bool arfs_cmp(const struct arfs_tuple *tuple, const struct flow_keys *fk) { - if (tuple->etype == htons(ETH_P_IP) && - tuple->src_ipv4 == ip_hdr(skb)->saddr && - tuple->dst_ipv4 == ip_hdr(skb)->daddr) - return true; - if (tuple->etype == htons(ETH_P_IPV6) && - (!memcmp(&tuple->src_ipv6, &ipv6_hdr(skb)->saddr, - sizeof(struct in6_addr))) && - (!memcmp(&tuple->dst_ipv6, &ipv6_hdr(skb)->daddr, - sizeof(struct in6_addr)))) - return true; + if (tuple->src_port != fk->ports.src || tuple->dst_port != fk->ports.dst) + return false; + if (tuple->etype != fk->basic.n_proto) + return false; + if (tuple->etype == htons(ETH_P_IP)) + return tuple->src_ipv4 == fk->addrs.v4addrs.src && + tuple->dst_ipv4 == fk->addrs.v4addrs.dst; + if (tuple->etype == htons(ETH_P_IPV6)) + return !memcmp(&tuple->src_ipv6, &fk->addrs.v6addrs.src, + sizeof(struct in6_addr)) && + !memcmp(&tuple->dst_ipv6, &fk->addrs.v6addrs.dst, + sizeof(struct in6_addr)); return false; }
static struct arfs_rule *arfs_find_rule(struct arfs_table *arfs_t, - const struct sk_buff *skb) + const struct flow_keys *fk) { struct arfs_rule *arfs_rule; struct hlist_head *head; - __be16 src_port = arfs_get_src_port(skb); - __be16 dst_port = arfs_get_dst_port(skb);
- head = arfs_hash_bucket(arfs_t, src_port, dst_port); + head = arfs_hash_bucket(arfs_t, fk->ports.src, fk->ports.dst); hlist_for_each_entry(arfs_rule, head, hlist) { - if (arfs_rule->tuple.src_port == src_port && - arfs_rule->tuple.dst_port == dst_port && - arfs_cmp_ips(&arfs_rule->tuple, skb)) { + if (arfs_cmp(&arfs_rule->tuple, fk)) return arfs_rule; - } }
return NULL; @@ -706,20 +674,24 @@ int mlx5e_rx_flow_steer(struct net_devic struct mlx5e_arfs_tables *arfs = &priv->fs.arfs; struct arfs_table *arfs_t; struct arfs_rule *arfs_rule; + struct flow_keys fk; + + if (!skb_flow_dissect_flow_keys(skb, &fk, 0)) + return -EPROTONOSUPPORT;
- if (skb->protocol != htons(ETH_P_IP) && - skb->protocol != htons(ETH_P_IPV6)) + if (fk.basic.n_proto != htons(ETH_P_IP) && + fk.basic.n_proto != htons(ETH_P_IPV6)) return -EPROTONOSUPPORT;
if (skb->encapsulation) return -EPROTONOSUPPORT;
- arfs_t = arfs_get_table(arfs, arfs_get_ip_proto(skb), skb->protocol); + arfs_t = arfs_get_table(arfs, fk.basic.ip_proto, fk.basic.n_proto); if (!arfs_t) return -EPROTONOSUPPORT;
spin_lock_bh(&arfs->arfs_lock); - arfs_rule = arfs_find_rule(arfs_t, skb); + arfs_rule = arfs_find_rule(arfs_t, &fk); if (arfs_rule) { if (arfs_rule->rxq == rxq_index) { spin_unlock_bh(&arfs->arfs_lock); @@ -727,8 +699,7 @@ int mlx5e_rx_flow_steer(struct net_devic } arfs_rule->rxq = rxq_index; } else { - arfs_rule = arfs_alloc_rule(priv, arfs_t, skb, - rxq_index, flow_id); + arfs_rule = arfs_alloc_rule(priv, arfs_t, &fk, rxq_index, flow_id); if (!arfs_rule) { spin_unlock_bh(&arfs->arfs_lock); return -ENOMEM;