From: Florian Fainelli <f.fainelli@gmail.com>
To: netdev@vger.kernel.org
Cc: davem@davemloft.net, gregkh@linuxfoundation.org,
stable@vger.kernel.org, edumazet@google.com,
sthemmin@microsoft.com, Florian Westphal <fw@strlen.de>,
Peter Oskolkov <posk@google.com>
Subject: [PATCH stable 4.9 22/29] ipv6: defrag: drop non-last frags smaller than min mtu
Date: Tue, 9 Oct 2018 15:49:17 -0700 [thread overview]
Message-ID: <20181009224924.30151-23-f.fainelli@gmail.com> (raw)
In-Reply-To: <20181009224924.30151-1-f.fainelli@gmail.com>
From: Florian Westphal <fw@strlen.de>
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)
---
net/ipv6/netfilter/nf_conntrack_reasm.c | 4 ++++
net/ipv6/reassembly.c | 4 ++++
2 files changed, 8 insertions(+)
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) {
--
2.17.1
next prev parent reply other threads:[~2018-10-10 6:09 UTC|newest]
Thread overview: 34+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-10-09 22:48 [PATCH stable 4.9 00/29] backport of IP fragmentation fixes Florian Fainelli
2018-10-09 22:48 ` [PATCH stable 4.9 01/29] inet: frags: change inet_frags_init_net() return value Florian Fainelli
2018-10-09 22:48 ` [PATCH stable 4.9 02/29] inet: frags: add a pointer to struct netns_frags Florian Fainelli
2018-10-09 22:48 ` [PATCH stable 4.9 03/29] inet: frags: refactor ipfrag_init() Florian Fainelli
2018-10-09 22:48 ` [PATCH stable 4.9 04/29] inet: frags: refactor ipv6_frag_init() Florian Fainelli
2018-10-09 22:49 ` [PATCH stable 4.9 05/29] inet: frags: refactor lowpan_net_frag_init() Florian Fainelli
2018-10-09 22:49 ` [PATCH stable 4.9 06/29] ipv6: export ip6 fragments sysctl to unprivileged users Florian Fainelli
2018-10-09 22:49 ` [PATCH stable 4.9 07/29] rhashtable: add schedule points Florian Fainelli
2018-10-09 22:49 ` [PATCH stable 4.9 08/29] inet: frags: use rhashtables for reassembly units Florian Fainelli
2018-10-09 22:49 ` [PATCH stable 4.9 09/29] inet: frags: remove some helpers Florian Fainelli
2018-10-09 22:49 ` [PATCH stable 4.9 10/29] inet: frags: get rif of inet_frag_evicting() Florian Fainelli
2018-10-09 22:49 ` [PATCH stable 4.9 11/29] inet: frags: remove inet_frag_maybe_warn_overflow() Florian Fainelli
2018-10-09 22:49 ` [PATCH stable 4.9 12/29] inet: frags: break the 2GB limit for frags storage Florian Fainelli
2018-10-09 22:49 ` [PATCH stable 4.9 13/29] inet: frags: do not clone skb in ip_expire() Florian Fainelli
2018-10-09 22:49 ` [PATCH stable 4.9 14/29] ipv6: frags: rewrite ip6_expire_frag_queue() Florian Fainelli
2018-10-09 22:49 ` [PATCH stable 4.9 15/29] rhashtable: reorganize struct rhashtable layout Florian Fainelli
2018-10-09 22:49 ` [PATCH stable 4.9 16/29] inet: frags: reorganize struct netns_frags Florian Fainelli
2018-10-09 22:49 ` [PATCH stable 4.9 17/29] inet: frags: get rid of ipfrag_skb_cb/FRAG_CB Florian Fainelli
2018-10-09 22:49 ` [PATCH stable 4.9 18/29] inet: frags: fix ip6frag_low_thresh boundary Florian Fainelli
2018-10-09 22:49 ` [PATCH stable 4.9 19/29] ip: discard IPv4 datagrams with overlapping segments Florian Fainelli
2018-10-09 22:49 ` [PATCH stable 4.9 20/29] net: speed up skb_rbtree_purge() Florian Fainelli
2018-10-09 22:49 ` [PATCH stable 4.9 21/29] net: modify skb_rbtree_purge to return the truesize of all purged skbs Florian Fainelli
2018-10-09 22:49 ` Florian Fainelli [this message]
2018-10-09 22:49 ` [PATCH stable 4.9 23/29] net: pskb_trim_rcsum() and CHECKSUM_COMPLETE are friends Florian Fainelli
2018-10-09 22:49 ` [PATCH stable 4.9 24/29] net: add rb_to_skb() and other rb tree helpers Florian Fainelli
2018-10-09 22:49 ` [PATCH stable 4.9 25/29] net: sk_buff rbnode reorg Florian Fainelli
2018-10-09 22:49 ` [PATCH stable 4.9 26/29] ipv4: frags: precedence bug in ip_expire() Florian Fainelli
2018-10-09 22:49 ` [PATCH stable 4.9 27/29] ip: add helpers to process in-order fragments faster Florian Fainelli
2018-10-09 22:49 ` [PATCH stable 4.9 28/29] ip: process in-order fragments efficiently Florian Fainelli
2018-10-09 22:49 ` [PATCH stable 4.9 29/29] ip: frags: fix crash in ip_do_fragment() Florian Fainelli
2018-10-10 0:46 ` [PATCH stable 4.9 00/29] backport of IP fragmentation fixes Eric Dumazet
2018-10-10 4:15 ` Florian Fainelli
2018-10-10 23:18 ` Stephen Hemminger
2018-10-10 23:23 ` Florian Fainelli
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