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ipv6: tcp: add a missing nf_reset_ct() in 3WHS handling

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Commit b0e214d212 ("netfilter: keep conntrack reference until
IPsecv6 policy checks are done") is a direct copy of the old
commit b59c270104 ("[NETFILTER]: Keep conntrack reference until
IPsec policy checks are done") but for IPv6.  However, it also
copies a bug that this old commit had.  That is: when the third
packet of 3WHS connection establishment contains payload, it is
added into socket receive queue without the XFRM check and the
drop of connection tracking context.

That leads to nf_conntrack module being impossible to unload as
it waits for all the conntrack references to be dropped while
the packet release is deferred in per-cpu cache indefinitely, if
not consumed by the application.

The issue for IPv4 was fixed in commit 6f0012e351 ("tcp: add a
missing nf_reset_ct() in 3WHS handling") by adding a missing XFRM
check and correctly dropping the conntrack context.  However, the
issue was introduced to IPv6 code afterwards.  Fixing it the
same way for IPv6 now.

Fixes: b0e214d212 ("netfilter: keep conntrack reference until IPsecv6 policy checks are done")
Link: https://lore.kernel.org/netdev/d589a999-d4dd-2768-b2d5-89dec64a4a42@ovn.org/
Signed-off-by: Ilya Maximets <i.maximets@ovn.org>
Acked-by: Florian Westphal <fw@strlen.de>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/r/20230922210530.2045146-1-i.maximets@ovn.org
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
This commit is contained in:
Ilya Maximets 2023-09-22 23:04:58 +02:00 committed by Paolo Abeni
parent 4b2b606075
commit 9593c7cb6c
1 changed files with 7 additions and 3 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

10
net/ipv6/tcp_ipv6.c
View File

@ -1640,9 +1640,12 @@ process:
struct sock *nsk;
sk = req->rsk_listener;
drop_reason = tcp_inbound_md5_hash(sk, skb,
&hdr->saddr, &hdr->daddr,
AF_INET6, dif, sdif);
if (!xfrm6_policy_check(sk, XFRM_POLICY_IN, skb))
drop_reason = SKB_DROP_REASON_XFRM_POLICY;
else
drop_reason = tcp_inbound_md5_hash(sk, skb,
&hdr->saddr, &hdr->daddr,
AF_INET6, dif, sdif);
if (drop_reason) {
sk_drops_add(sk, skb);
reqsk_put(req);
@ -1689,6 +1692,7 @@ process:
}
goto discard_and_relse;
}
nf_reset_ct(skb);
if (nsk == sk) {
reqsk_put(req);
tcp_v6_restore_cb(skb);