netfilter: conntrack: restore IPS_CONFIRMED out of nf_conntrack_hash_check_insert()
authorPablo Neira Ayuso <pablo@netfilter.org>
Tue, 18 Apr 2023 21:31:26 +0000 (23:31 +0200)
committerPablo Neira Ayuso <pablo@netfilter.org>
Wed, 19 Apr 2023 08:07:59 +0000 (10:07 +0200)
e6d57e9ff0ae ("netfilter: conntrack: fix rmmod double-free race")
consolidates IPS_CONFIRMED bit set in nf_conntrack_hash_check_insert().
However, this breaks ctnetlink:

 # conntrack -I -p tcp --timeout 123 --src 1.2.3.4 --dst 5.6.7.8 --state ESTABLISHED --sport 1 --dport 4 -u SEEN_REPLY
 conntrack v1.4.6 (conntrack-tools): Operation failed: Device or resource busy

This is a partial revert of the aforementioned commit to restore
IPS_CONFIRMED.

Fixes: e6d57e9ff0ae ("netfilter: conntrack: fix rmmod double-free race")
Reported-by: Stéphane Graber <stgraber@stgraber.org>
Tested-by: Stéphane Graber <stgraber@stgraber.org>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
net/netfilter/nf_conntrack_bpf.c
net/netfilter/nf_conntrack_core.c
net/netfilter/nf_conntrack_netlink.c

index cd99e6d..3491352 100644 (file)
@@ -381,6 +381,7 @@ __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;
 
+       nfct->status |= IPS_CONFIRMED;
        err = nf_conntrack_hash_check_insert(nfct);
        if (err < 0) {
                nf_conntrack_free(nfct);
index c6a6a60..7ba6ab9 100644 (file)
@@ -932,7 +932,6 @@ nf_conntrack_hash_check_insert(struct nf_conn *ct)
                goto out;
        }
 
-       ct->status |= IPS_CONFIRMED;
        smp_wmb();
        /* The caller holds a reference to this object */
        refcount_set(&ct->ct_general.use, 2);
index bfc3aaa..d3ee188 100644 (file)
@@ -2316,6 +2316,9 @@ ctnetlink_create_conntrack(struct net *net,
        nfct_seqadj_ext_add(ct);
        nfct_synproxy_ext_add(ct);
 
+       /* we must add conntrack extensions before confirmation. */
+       ct->status |= IPS_CONFIRMED;
+
        if (cda[CTA_STATUS]) {
                err = ctnetlink_change_status(ct, cda);
                if (err < 0)