From: Guillaume Nault gnault@redhat.com
[ Upstream commit 8a3dca632538c550930ce8bafa8c906b130d35cf ]
When fixing the skb leak introduced by the conversion to rbtree, I forgot about the special case of duplicate fragments. The condition under the 'insert_error' label isn't effective anymore as nf_ct_frg6_gather() doesn't override the returned value anymore. So duplicate fragments now get NF_DROP verdict.
To accept duplicate fragments again, handle them specially as soon as inet_frag_queue_insert() reports them. Return -EINPROGRESS which will translate to NF_STOLEN verdict, like any accepted fragment. However, such packets don't carry any new information and aren't queued, so we just drop them immediately.
Fixes: a0d56cb911ca ("netfilter: ipv6: nf_defrag: fix leakage of unqueued fragments") Signed-off-by: Guillaume Nault gnault@redhat.com Signed-off-by: Pablo Neira Ayuso pablo@netfilter.org Signed-off-by: Sasha Levin sashal@kernel.org --- net/ipv6/netfilter/nf_conntrack_reasm.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-)
diff --git a/net/ipv6/netfilter/nf_conntrack_reasm.c b/net/ipv6/netfilter/nf_conntrack_reasm.c index 5b3f65e29b6f..8951de8b568f 100644 --- a/net/ipv6/netfilter/nf_conntrack_reasm.c +++ b/net/ipv6/netfilter/nf_conntrack_reasm.c @@ -265,8 +265,14 @@ static int nf_ct_frag6_queue(struct frag_queue *fq, struct sk_buff *skb,
prev = fq->q.fragments_tail; err = inet_frag_queue_insert(&fq->q, skb, offset, end); - if (err) + if (err) { + if (err == IPFRAG_DUP) { + /* No error for duplicates, pretend they got queued. */ + kfree_skb(skb); + return -EINPROGRESS; + } goto insert_error; + }
if (dev) fq->iif = dev->ifindex; @@ -304,8 +310,6 @@ static int nf_ct_frag6_queue(struct frag_queue *fq, struct sk_buff *skb, return -EINPROGRESS;
insert_error: - if (err == IPFRAG_DUP) - goto err; inet_frag_kill(&fq->q); err: skb_dst_drop(skb);