This is a note to let you know that I've just added the patch titled netfilter: allow ipv6 fragments to arrive on different devices to the 5.4-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: netfilter-allow-ipv6-fragments-to-arrive-on-differen.patch and it can be found in the queue-5.4 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit 33b64cb513359df11f7e2931f56c55f0efeebf2a Author: Tom Hughes <tom@xxxxxxxxxx> Date: Tue Aug 6 12:40:52 2024 +0100 netfilter: allow ipv6 fragments to arrive on different devices [ Upstream commit 3cd740b985963f874a1a094f1969e998b9d05554 ] Commit 264640fc2c5f4 ("ipv6: distinguish frag queues by device for multicast and link-local packets") modified the ipv6 fragment reassembly logic to distinguish frag queues by device for multicast and link-local packets but in fact only the main reassembly code limits the use of the device to those address types and the netfilter reassembly code uses the device for all packets. This means that if fragments of a packet arrive on different interfaces then netfilter will fail to reassemble them and the fragments will be expired without going any further through the filters. Fixes: 648700f76b03 ("inet: frags: use rhashtables for reassembly units") Signed-off-by: Tom Hughes <tom@xxxxxxxxxx> Signed-off-by: Pablo Neira Ayuso <pablo@xxxxxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/net/ipv6/netfilter/nf_conntrack_reasm.c b/net/ipv6/netfilter/nf_conntrack_reasm.c index 24ec295454940..db4592ada9491 100644 --- a/net/ipv6/netfilter/nf_conntrack_reasm.c +++ b/net/ipv6/netfilter/nf_conntrack_reasm.c @@ -155,6 +155,10 @@ static struct frag_queue *fq_find(struct net *net, __be32 id, u32 user, }; struct inet_frag_queue *q; + if (!(ipv6_addr_type(&hdr->daddr) & (IPV6_ADDR_MULTICAST | + IPV6_ADDR_LINKLOCAL))) + key.iif = 0; + q = inet_frag_find(nf_frag->fqdir, &key); if (!q) return NULL;