diff options
| author | Huajian Yang <huajianyang@asrmicro.com> | 2025-04-17 12:29:53 +0300 |
|---|---|---|
| committer | Pablo Neira Ayuso <pablo@netfilter.org> | 2025-05-05 14:13:08 +0300 |
| commit | aa04c6f45b9224b949aa35d4fa5f8d0ba07b23d4 (patch) | |
| tree | 84955fd7e07c5cc802e1bf2ecad2389053d6b729 | |
| parent | 836b313a14a316290886dcc2ce7e78bf5ecc8658 (diff) | |
| download | linux-aa04c6f45b9224b949aa35d4fa5f8d0ba07b23d4.tar.xz | |
netfilter: bridge: Move specific fragmented packet to slow_path instead of dropping it
The config NF_CONNTRACK_BRIDGE will change the bridge forwarding for
fragmented packets.
The original bridge does not know that it is a fragmented packet and
forwards it directly, after NF_CONNTRACK_BRIDGE is enabled, function
nf_br_ip_fragment and br_ip6_fragment will check the headroom.
In original br_forward, insufficient headroom of skb may indeed exist,
but there's still a way to save the skb in the device driver after
dev_queue_xmit.So droping the skb will change the original bridge
forwarding in some cases.
Fixes: 3c171f496ef5 ("netfilter: bridge: add connection tracking system")
Signed-off-by: Huajian Yang <huajianyang@asrmicro.com>
Reviewed-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
| -rw-r--r-- | net/bridge/netfilter/nf_conntrack_bridge.c | 12 | ||||
| -rw-r--r-- | net/ipv6/netfilter.c | 12 |
2 files changed, 12 insertions, 12 deletions
diff --git a/net/bridge/netfilter/nf_conntrack_bridge.c b/net/bridge/netfilter/nf_conntrack_bridge.c index 816bb0fde718..6482de4d8750 100644 --- a/net/bridge/netfilter/nf_conntrack_bridge.c +++ b/net/bridge/netfilter/nf_conntrack_bridge.c @@ -60,19 +60,19 @@ static int nf_br_ip_fragment(struct net *net, struct sock *sk, struct ip_fraglist_iter iter; struct sk_buff *frag; - if (first_len - hlen > mtu || - skb_headroom(skb) < ll_rs) + if (first_len - hlen > mtu) goto blackhole; - if (skb_cloned(skb)) + if (skb_cloned(skb) || + skb_headroom(skb) < ll_rs) goto slow_path; skb_walk_frags(skb, frag) { - if (frag->len > mtu || - skb_headroom(frag) < hlen + ll_rs) + if (frag->len > mtu) goto blackhole; - if (skb_shared(frag)) + if (skb_shared(frag) || + skb_headroom(frag) < hlen + ll_rs) goto slow_path; } diff --git a/net/ipv6/netfilter.c b/net/ipv6/netfilter.c index 581ce055bf52..4541836ee3da 100644 --- a/net/ipv6/netfilter.c +++ b/net/ipv6/netfilter.c @@ -164,20 +164,20 @@ int br_ip6_fragment(struct net *net, struct sock *sk, struct sk_buff *skb, struct ip6_fraglist_iter iter; struct sk_buff *frag2; - if (first_len - hlen > mtu || - skb_headroom(skb) < (hroom + sizeof(struct frag_hdr))) + if (first_len - hlen > mtu) goto blackhole; - if (skb_cloned(skb)) + if (skb_cloned(skb) || + skb_headroom(skb) < (hroom + sizeof(struct frag_hdr))) goto slow_path; skb_walk_frags(skb, frag2) { - if (frag2->len > mtu || - skb_headroom(frag2) < (hlen + hroom + sizeof(struct frag_hdr))) + if (frag2->len > mtu) goto blackhole; /* Partially cloned skb? */ - if (skb_shared(frag2)) + if (skb_shared(frag2) || + skb_headroom(frag2) < (hlen + hroom + sizeof(struct frag_hdr))) goto slow_path; } |