net: openvswitch: fix possible kfree_skb of ERR_PTR

After the patch in the "Fixes" tag, the allocation of the "reply" skb
can happen either before or after locking the ovs_mutex.

However, error cleanups still follow the classical reversed order,
assuming "reply" is allocated before locking: it is freed after unlocking.

If "reply" allocation happens after locking the mutex and it fails,
"reply" is left with an ERR_PTR, and execution jumps to the correspondent
cleanup stage which will try to free an invalid pointer.

Fix this by setting the pointer to NULL after having saved its error
value.

Fixes: 893f139b9a6c ("openvswitch: Minimize ovs_flow_cmd_new|set critical sections.")
Signed-off-by: Adrian Moreno <amorenoz@redhat.com>
Reviewed-by: Aaron Conole <aconole@redhat.com>
Acked-by: Eelco Chaudron <echaudro@redhat.com>
Link: https://patch.msgid.link/20260604121946.942164-1-amorenoz@redhat.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/net/openvswitch/datapath.c b/net/openvswitch/datapath.c
index bbbde50fc6498f8af4c70bbc71c7e2c59abef874..f0164817d9b72384b07634502e7f29febcf48dbd 100644 (file)
--- a/net/openvswitch/datapath.c
+++ b/net/openvswitch/datapath.c
@@ -1316,6 +1316,7 @@ static int ovs_flow_cmd_set(struct sk_buff *skb, struct genl_info *info)
 
                if (IS_ERR(reply)) {
                        error = PTR_ERR(reply);
+                       reply = NULL;
                        goto err_unlock_ovs;
                }
        }