netfilter, bpf: Adjust timeouts of non-confirmed CTs in bpf_ct_insert_entry()

Bugzilla: https://bugzilla.redhat.com/2221599

Upstream Status: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git

commit 837723b
Author: Ilya Leoshkevich <iii@linux.ibm.com>
Date:   Wed Aug 30 03:07:43 2023 +0200

    netfilter, bpf: Adjust timeouts of non-confirmed CTs in bpf_ct_insert_entry()

    bpf_nf testcase fails on s390x: bpf_skb_ct_lookup() cannot find the entry
    that was added by bpf_ct_insert_entry() within the same BPF function.

    The reason is that this entry is deleted by nf_ct_gc_expired().

    The CT timeout starts ticking after the CT confirmation; therefore
    nf_conn.timeout is initially set to the timeout value, and
    __nf_conntrack_confirm() sets it to the deadline value.

    bpf_ct_insert_entry() sets IPS_CONFIRMED_BIT, but does not adjust the
    timeout, making its value meaningless and causing false positives.

    Fix the problem by making bpf_ct_insert_entry() adjust the timeout,
    like __nf_conntrack_confirm().

    Fixes: 2cdaa3e ("netfilter: conntrack: restore IPS_CONFIRMED out of nf_conntrack_hash_check_insert()")
    Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
    Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
    Cc: Florian Westphal <fw@strlen.de>
    Link: https://lore.kernel.org/bpf/20230830011128.1415752-3-iii@linux.ibm.com
    Signed-off-by: Alexei Starovoitov <ast@kernel.org>

Signed-off-by: Artem Savkov <asavkov@redhat.com>

Author: sm00th

net/netfilter/nf_conntrack_bpf.c

@@ -380,6 +380,8 @@ __bpf_kfunc struct nf_conn *bpf_ct_insert_entry(struct nf_conn___init *nfct_i)
 	struct nf_conn *nfct = (struct nf_conn *)nfct_i;
 	int err;
 
+	if (!nf_ct_is_confirmed(nfct))
+		nfct->timeout += nfct_time_stamp;
 	nfct->status |= IPS_CONFIRMED;
 	err = nf_conntrack_hash_check_insert(nfct);
 	if (err < 0) {