From: Felix Kaechele felix@kaechele.ca
[ Upstream commit e7600865db32b69deb0109b8254244dca592adcf ]
Commit f8e608982022 ("netfilter: ctnetlink: Resolve conntrack L3-protocol flush regression") introduced a regression in which deletion of conntrack entries would fail because the L3 protocol information is replaced by AF_UNSPEC. As a result the search for the entry to be deleted would turn up empty due to the tuple used to perform the search is now different from the tuple used to initially set up the entry.
For flushing the conntrack table we do however want to keep the option for nfgenmsg->version to have a non-zero value to allow for newer user-space tools to request treatment under the new behavior. With that it is possible to independently flush tables for a defined L3 protocol. This was introduced with the enhancements in in commit 59c08c69c278 ("netfilter: ctnetlink: Support L3 protocol-filter on flush").
Older user-space tools will retain the behavior of flushing all tables regardless of defined L3 protocol.
Fixes: f8e608982022 ("netfilter: ctnetlink: Resolve conntrack L3-protocol flush regression") Suggested-by: Pablo Neira Ayuso pablo@netfilter.org Signed-off-by: Felix Kaechele felix@kaechele.ca Signed-off-by: Pablo Neira Ayuso pablo@netfilter.org Signed-off-by: Sasha Levin sashal@kernel.org --- net/netfilter/nf_conntrack_netlink.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-)
diff --git a/net/netfilter/nf_conntrack_netlink.c b/net/netfilter/nf_conntrack_netlink.c index 7db79c1b8084..1b77444d5b52 100644 --- a/net/netfilter/nf_conntrack_netlink.c +++ b/net/netfilter/nf_conntrack_netlink.c @@ -1256,7 +1256,6 @@ static int ctnetlink_del_conntrack(struct net *net, struct sock *ctnl, struct nf_conntrack_tuple tuple; struct nf_conn *ct; struct nfgenmsg *nfmsg = nlmsg_data(nlh); - u_int8_t u3 = nfmsg->version ? nfmsg->nfgen_family : AF_UNSPEC; struct nf_conntrack_zone zone; int err;
@@ -1266,11 +1265,13 @@ static int ctnetlink_del_conntrack(struct net *net, struct sock *ctnl,
if (cda[CTA_TUPLE_ORIG]) err = ctnetlink_parse_tuple(cda, &tuple, CTA_TUPLE_ORIG, - u3, &zone); + nfmsg->nfgen_family, &zone); else if (cda[CTA_TUPLE_REPLY]) err = ctnetlink_parse_tuple(cda, &tuple, CTA_TUPLE_REPLY, - u3, &zone); + nfmsg->nfgen_family, &zone); else { + u_int8_t u3 = nfmsg->version ? nfmsg->nfgen_family : AF_UNSPEC; + return ctnetlink_flush_conntrack(net, cda, NETLINK_CB(skb).portid, nlmsg_report(nlh), u3);