Re: [PATCH net 1/1] openvswitch: avoid reallocating confirmed conntrack labels

ovs_ct_get_conn_labels() adds the labels extension when a conntrack
entry does not have one.  Confirmed conntracks can be read locklessly,
so adding an extension may reallocate and free the extension block
while another CPU accesses it.

Only add the extension for unconfirmed conntracks.  A confirmed
conntrack without labels now fails the caller's label operation instead
of reallocating its extension storage.

Fixes: c2ac66735870 ("openvswitch: Allow matching on conntrack label")
Cc: stable@vger.kernel.org
Reported-by: Vega <redacted>
Assisted-by: LLM
Signed-off-by: Zhiling Zou <redacted>
---
 net/openvswitch/conntrack.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/openvswitch/conntrack.c b/net/openvswitch/conntrack.c
index 27115967e5d93..0f433688e17b9 100644
--- a/net/openvswitch/conntrack.c
+++ b/net/openvswitch/conntrack.c

@@ -366,7 +366,7 @@ static struct nf_conn_labels *ovs_ct_get_conn_labels(struct nf_conn *ct)
 	struct nf_conn_labels *cl;
 
 	cl = nf_ct_labels_find(ct);
-	if (!cl) {
+	if (!cl && !nf_ct_is_confirmed(ct)) {
 		nf_ct_labels_ext_add(ct);
 		cl = nf_ct_labels_find(ct);
 	}