5.10-stable review patch. If anyone has any objections, please let me know. ------------------ From: Ilya Maximets [ Upstream commit 1a4151e6be57b098b7a5ebfbde58585e83200cdc ] While calling the helpers, a raw pointer to the extensions area is wired into expectations list: -> nf_ct_helper() -> helper->help() -> nf_ct_expect_related_report() -> nf_ct_expect_insert() -> hlist_add_head_rcu(&exp->lnode, &master_help->expectations) In case the connection is not confirmed yet, more extensions can be added afterwards with *_ext_add() calls reallocating the extension space and leaving the now invalid pointer in the expectations list that is later accessed while removing the expectation. Make sure that helpers are called at the end after all the other extensions are already added. Note that the helper rejection now leaves the mark and labels set, but that's not different from how the NAT was handled before or how the mark and the labels were handled on confirmation failure. And there are no atomicity guarantees provided by the API anyway. Fixes: cae3a2627520 ("openvswitch: Allow attaching helpers to ct action") Cc: stable@vger.kernel.org Reported-by: Axel Mierczuk Signed-off-by: Ilya Maximets Reviewed-by: Aaron Conole Link: https://patch.msgid.link/20260921145655.3167436-4-i.maximets@ovn.org Signed-off-by: Jakub Kicinski [ adapted nf_ct_helper() calls to the existing ovs_ct_helper() API. ] Signed-off-by: Sasha Levin --- net/openvswitch/conntrack.c | 20 +++++++++++++------- 1 file changed, 13 insertions(+), 7 deletions(-) diff --git a/net/openvswitch/conntrack.c b/net/openvswitch/conntrack.c index 340f7dde559f5..196e7f7c82e1c 100644 --- a/net/openvswitch/conntrack.c +++ b/net/openvswitch/conntrack.c @@ -1038,14 +1038,14 @@ static int __ovs_ct_lookup(struct net *net, struct sw_flow_key *key, } } - /* Call the helper only if: - * - nf_conntrack_in() was executed above ("!cached") or a - * helper was just attached ("add_helper") for a confirmed - * connection, or - * - When committing an unconfirmed connection. + /* Call the helper only if nf_conntrack_in() was executed + * above ("!cached") or a helper was just attached ("add_helper"). + * + * For unconfirmed connections it will be called later during + * commit as we need to have all the other extensions allocated + * before the call. */ - if ((nf_ct_is_confirmed(ct) ? !cached || add_helper : - info->commit) && + if (nf_ct_is_confirmed(ct) && (!cached || add_helper) && ovs_ct_helper(skb, info->family) != NF_ACCEPT) { return -EINVAL; } @@ -1253,6 +1253,12 @@ static int ovs_ct_commit(struct net *net, struct sw_flow_key *key, &info->labels.mask); if (err) return err; + + /* Call the helpers now. We couldn't do this before as + * all the extensions must be allocated before the call. + */ + if (ovs_ct_helper(skb, info->family) != NF_ACCEPT) + return -EINVAL; } else if (IS_ENABLED(CONFIG_NF_CONNTRACK_LABELS) && labels_nonzero(&info->labels.mask)) { err = ovs_ct_set_labels(ct, key, &info->labels.value, -- 2.53.0