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| author | Florian Westphal <fw@strlen.de> | 2018-10-10 12:30:10 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-10-18 09:13:26 +0200 |
| commit | a8444b1ccb20339774af58e40ad42296074fb484 (patch) | |
| tree | 94f268a7521ca3c7ebbf77a617578d710a00cb3a | |
| parent | 871695951ec6f6b0b1a258c9bb5336bfeffab409 (diff) | |
| download | linux-a8444b1ccb20339774af58e40ad42296074fb484.tar.gz linux-a8444b1ccb20339774af58e40ad42296074fb484.tar.bz2 linux-a8444b1ccb20339774af58e40ad42296074fb484.zip | |
ipv6: defrag: drop non-last frags smaller than min mtu
don't bother with pathological cases, they only waste cycles.
IPv6 requires a minimum MTU of 1280 so we should never see fragments
smaller than this (except last frag).
v3: don't use awkward "-offset + len"
v2: drop IPv4 part, which added same check w. IPV4_MIN_MTU (68).
There were concerns that there could be even smaller frags
generated by intermediate nodes, e.g. on radio networks.
Cc: Peter Oskolkov <posk@google.com>
Cc: Eric Dumazet <edumazet@google.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
(cherry picked from commit 0ed4229b08c13c84a3c301a08defdc9e7f4467e6)
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | net/ipv6/netfilter/nf_conntrack_reasm.c | 4 | ||||
| -rw-r--r-- | net/ipv6/reassembly.c | 4 |
2 files changed, 8 insertions, 0 deletions
diff --git a/net/ipv6/netfilter/nf_conntrack_reasm.c b/net/ipv6/netfilter/nf_conntrack_reasm.c index ff49d1f2c8cb..b81541701346 100644 --- a/net/ipv6/netfilter/nf_conntrack_reasm.c +++ b/net/ipv6/netfilter/nf_conntrack_reasm.c @@ -564,6 +564,10 @@ int nf_ct_frag6_gather(struct net *net, struct sk_buff *skb, u32 user) hdr = ipv6_hdr(skb); fhdr = (struct frag_hdr *)skb_transport_header(skb); + if (skb->len - skb_network_offset(skb) < IPV6_MIN_MTU && + fhdr->frag_off & htons(IP6_MF)) + return -EINVAL; + skb_orphan(skb); fq = fq_find(net, fhdr->identification, user, hdr, skb->dev ? skb->dev->ifindex : 0); diff --git a/net/ipv6/reassembly.c b/net/ipv6/reassembly.c index dbe726c9a2ae..78656bbe50e7 100644 --- a/net/ipv6/reassembly.c +++ b/net/ipv6/reassembly.c @@ -516,6 +516,10 @@ static int ipv6_frag_rcv(struct sk_buff *skb) return 1; } + if (skb->len - skb_network_offset(skb) < IPV6_MIN_MTU && + fhdr->frag_off & htons(IP6_MF)) + goto fail_hdr; + iif = skb->dev ? skb->dev->ifindex : 0; fq = fq_find(net, fhdr->identification, hdr, iif); if (fq) { |