diff options
| author | Hagen Paul Pfeifer <hagen@jauu.net> | 2015-01-15 22:34:25 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2015-02-26 17:50:10 -0800 |
| commit | 7aa58c2255e9e05585842c8d83949f4191fe1abf (patch) | |
| tree | f2c09e4c6356d4f2761ced27ff885933f4c4a837 /net/ipv6 | |
| parent | 64d76f569ae7f966b9e5fa26fd6d822df8d2f96f (diff) | |
| download | lwn-7aa58c2255e9e05585842c8d83949f4191fe1abf.tar.gz lwn-7aa58c2255e9e05585842c8d83949f4191fe1abf.zip | |
ipv6: stop sending PTB packets for MTU < 1280
[ Upstream commit 9d289715eb5c252ae15bd547cb252ca547a3c4f2 ]
Reduce the attack vector and stop generating IPv6 Fragment Header for
paths with an MTU smaller than the minimum required IPv6 MTU
size (1280 byte) - called atomic fragments.
See IETF I-D "Deprecating the Generation of IPv6 Atomic Fragments" [1]
for more information and how this "feature" can be misused.
[1] https://tools.ietf.org/html/draft-ietf-6man-deprecate-atomfrag-generation-00
Signed-off-by: Fernando Gont <fgont@si6networks.com>
Signed-off-by: Hagen Paul Pfeifer <hagen@jauu.net>
Acked-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'net/ipv6')
| -rw-r--r-- | net/ipv6/route.c | 7 |
1 files changed, 2 insertions, 5 deletions
diff --git a/net/ipv6/route.c b/net/ipv6/route.c index 7cc1102e298c..6f1b8503a431 100644 --- a/net/ipv6/route.c +++ b/net/ipv6/route.c @@ -1160,12 +1160,9 @@ static void ip6_rt_update_pmtu(struct dst_entry *dst, struct sock *sk, struct net *net = dev_net(dst->dev); rt6->rt6i_flags |= RTF_MODIFIED; - if (mtu < IPV6_MIN_MTU) { - u32 features = dst_metric(dst, RTAX_FEATURES); + if (mtu < IPV6_MIN_MTU) mtu = IPV6_MIN_MTU; - features |= RTAX_FEATURE_ALLFRAG; - dst_metric_set(dst, RTAX_FEATURES, features); - } + dst_metric_set(dst, RTAX_MTU, mtu); rt6_update_expires(rt6, net->ipv6.sysctl.ip6_rt_mtu_expires); } |