This is a note to let you know that I've just added the patch titled
vti6: Don't report path MTU below IPV6_MIN_MTU.
to the 4.4-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git%3Ba=su...
The filename of the patch is: vti6-don-t-report-path-mtu-below-ipv6_min_mtu.patch and it can be found in the queue-4.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree, please let stable@vger.kernel.org know about it.
From foo@baz Tue Dec 12 13:38:50 CET 2017
From: Steffen Klassert steffen.klassert@secunet.com Date: Wed, 15 Feb 2017 11:38:58 +0100 Subject: vti6: Don't report path MTU below IPV6_MIN_MTU.
From: Steffen Klassert steffen.klassert@secunet.com
[ Upstream commit e3dc847a5f85b43ee2bfc8eae407a7e383483228 ]
In vti6_xmit(), the check for IPV6_MIN_MTU before we send a ICMPV6_PKT_TOOBIG message is missing. So we might report a PMTU below 1280. Fix this by adding the required check.
Fixes: ccd740cbc6e ("vti6: Add pmtu handling to vti6_xmit.") Signed-off-by: Steffen Klassert steffen.klassert@secunet.com Signed-off-by: Sasha Levin alexander.levin@verizon.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- net/ipv6/ip6_vti.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-)
--- a/net/ipv6/ip6_vti.c +++ b/net/ipv6/ip6_vti.c @@ -474,11 +474,15 @@ vti6_xmit(struct sk_buff *skb, struct ne if (!skb->ignore_df && skb->len > mtu) { skb_dst(skb)->ops->update_pmtu(dst, NULL, skb, mtu);
- if (skb->protocol == htons(ETH_P_IPV6)) + if (skb->protocol == htons(ETH_P_IPV6)) { + if (mtu < IPV6_MIN_MTU) + mtu = IPV6_MIN_MTU; + icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu); - else + } else { icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED, htonl(mtu)); + }
return -EMSGSIZE; }
Patches currently in stable-queue which might be from steffen.klassert@secunet.com are
queue-4.4/xfrm-copy-policy-family-in-clone_policy.patch queue-4.4/vti6-don-t-report-path-mtu-below-ipv6_min_mtu.patch