diff options
| author | Pablo Neira Ayuso <pablo@netfilter.org> | 2017-12-30 22:41:46 +0100 |
|---|---|---|
| committer | Pablo Neira Ayuso <pablo@netfilter.org> | 2018-01-08 18:11:04 +0100 |
| commit | a7f87b47e67e4341f6175cdb80e5c2eaadf30dcb (patch) | |
| tree | 47f8be7118f28a8d3f4920968c96d3cb596d7ef2 /net/ipv4/netfilter/nf_tables_ipv4.c | |
| parent | f6931f5f5b713705c3cc91e4f9c222f2b181e2ef (diff) | |
netfilter: remove defensive check on malformed packets from raw sockets
Users cannot forge malformed IPv4/IPv6 headers via raw sockets that they
can inject into the stack. Specifically, not for IPv4 since 55888dfb6ba7
("AF_RAW: Augment raw_send_hdrinc to expand skb to fit iphdr->ihl
(v2)"). IPv6 raw sockets also ensure that packets have a well-formed
IPv6 header available in the skbuff.
At quick glance, br_netfilter also validates layer 3 headers and it
drops malformed both IPv4 and IPv6 packets.
Therefore, let's remove this defensive check all over the place.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Diffstat (limited to 'net/ipv4/netfilter/nf_tables_ipv4.c')
| -rw-r--r-- | net/ipv4/netfilter/nf_tables_ipv4.c | 17 |
1 files changed, 1 insertions, 16 deletions
diff --git a/net/ipv4/netfilter/nf_tables_ipv4.c b/net/ipv4/netfilter/nf_tables_ipv4.c index 8aeb15c2b9b2..f4675253f1e6 100644 --- a/net/ipv4/netfilter/nf_tables_ipv4.c +++ b/net/ipv4/netfilter/nf_tables_ipv4.c @@ -30,21 +30,6 @@ static unsigned int nft_do_chain_ipv4(void *priv, return nft_do_chain(&pkt, priv); } -static unsigned int nft_ipv4_output(void *priv, - struct sk_buff *skb, - const struct nf_hook_state *state) -{ - if (unlikely(skb->len < sizeof(struct iphdr) || - ip_hdr(skb)->ihl < sizeof(struct iphdr) / 4)) { - if (net_ratelimit()) - pr_info("nf_tables_ipv4: ignoring short SOCK_RAW " - "packet\n"); - return NF_ACCEPT; - } - - return nft_do_chain_ipv4(priv, skb, state); -} - static struct nft_af_info nft_af_ipv4 __read_mostly = { .family = NFPROTO_IPV4, .nhooks = NF_INET_NUMHOOKS, @@ -91,7 +76,7 @@ static const struct nf_chain_type filter_ipv4 = { (1 << NF_INET_POST_ROUTING), .hooks = { [NF_INET_LOCAL_IN] = nft_do_chain_ipv4, - [NF_INET_LOCAL_OUT] = nft_ipv4_output, + [NF_INET_LOCAL_OUT] = nft_do_chain_ipv4, [NF_INET_FORWARD] = nft_do_chain_ipv4, [NF_INET_PRE_ROUTING] = nft_do_chain_ipv4, [NF_INET_POST_ROUTING] = nft_do_chain_ipv4, |