We must ensure that all interesting data is linear and not paged out to access all information in a header or a full batman-adv related packet. Otherwise we may drop packets which have non-linear headers but which hold valid data.
This doesn't affect non-linear skbs which have all headers in a linear head unless we must process the whole packet like in ogms or vis packets. Signed-off-by: Sven Eckelmann <[email protected]> --- drivers/staging/batman-adv/hard-interface.c | 2 +- drivers/staging/batman-adv/routing.c | 22 ++++++++++++++-------- 2 files changed, 15 insertions(+), 9 deletions(-) diff --git a/drivers/staging/batman-adv/hard-interface.c b/drivers/staging/batman-adv/hard-interface.c index f33c73f..c1863d2 100644 --- a/drivers/staging/batman-adv/hard-interface.c +++ b/drivers/staging/batman-adv/hard-interface.c @@ -486,7 +486,7 @@ int batman_skb_recv(struct sk_buff *skb, struct net_device *dev, goto err_free; /* packet should hold at least type and version */ - if (unlikely(skb_headlen(skb) < 2)) + if (unlikely(!pskb_may_pull(skb, 2))) goto err_free; /* expect a valid ethernet header here. */ diff --git a/drivers/staging/batman-adv/routing.c b/drivers/staging/batman-adv/routing.c index 7e993a2..6009adc 100644 --- a/drivers/staging/batman-adv/routing.c +++ b/drivers/staging/batman-adv/routing.c @@ -744,7 +744,7 @@ int recv_bat_packet(struct sk_buff *skb, unsigned long flags; /* drop packet if it has not necessary minimum size */ - if (skb_headlen(skb) < sizeof(struct batman_packet)) + if (unlikely(!pskb_may_pull(skb, sizeof(struct batman_packet)))) return NET_RX_DROP; ethhdr = (struct ethhdr *)skb_mac_header(skb); @@ -761,6 +761,10 @@ int recv_bat_packet(struct sk_buff *skb, if (skb_cow(skb, 0) < 0) return NET_RX_DROP; + /* keep skb linear */ + if (skb_linearize(skb) < 0) + return NET_RX_DROP; + ethhdr = (struct ethhdr *)skb_mac_header(skb); spin_lock_irqsave(&orig_hash_lock, flags); @@ -914,11 +918,11 @@ int recv_icmp_packet(struct sk_buff *skb) /** * we truncate all incoming icmp packets if they don't match our size */ - if (skb_headlen(skb) >= sizeof(struct icmp_packet_rr)) + if (skb->len >= sizeof(struct icmp_packet_rr)) hdr_size = sizeof(struct icmp_packet_rr); /* drop packet if it has not necessary minimum size */ - if (skb_headlen(skb) < hdr_size) + if (unlikely(!pskb_may_pull(skb, hdr_size))) return NET_RX_DROP; ethhdr = (struct ethhdr *)skb_mac_header(skb); @@ -1087,7 +1091,7 @@ static int check_unicast_packet(struct sk_buff *skb, int hdr_size) struct ethhdr *ethhdr; /* drop packet if it has not necessary minimum size */ - if (skb_headlen(skb) < hdr_size) + if (unlikely(!pskb_may_pull(skb, hdr_size))) return -1; ethhdr = (struct ethhdr *) skb_mac_header(skb); @@ -1247,7 +1251,7 @@ int recv_bcast_packet(struct sk_buff *skb) unsigned long flags; /* drop packet if it has not necessary minimum size */ - if (skb_headlen(skb) < hdr_size) + if (unlikely(!pskb_may_pull(skb, hdr_size))) return NET_RX_DROP; ethhdr = (struct ethhdr *)skb_mac_header(skb); @@ -1320,7 +1324,11 @@ int recv_vis_packet(struct sk_buff *skb) struct bat_priv *bat_priv; int hdr_size = sizeof(struct vis_packet); - if (skb_headlen(skb) < hdr_size) + /* keep skb linear */ + if (skb_linearize(skb) < 0) + return NET_RX_DROP; + + if (unlikely(!pskb_may_pull(skb, hdr_size))) return NET_RX_DROP; vis_packet = (struct vis_packet *) skb->data; @@ -1342,13 +1350,11 @@ int recv_vis_packet(struct sk_buff *skb) switch (vis_packet->vis_type) { case VIS_TYPE_SERVER_SYNC: - /* TODO: handle fragmented skbs properly */ receive_server_sync_packet(bat_priv, vis_packet, skb_headlen(skb)); break; case VIS_TYPE_CLIENT_UPDATE: - /* TODO: handle fragmented skbs properly */ receive_client_update_packet(bat_priv, vis_packet, skb_headlen(skb)); break; -- 1.7.1
