nfp: flower: Fix a potential leak in nfp_tunnel_add_shared_mac()

ida_simple_get() returns an id between min (0) and max (NFP_MAX_MAC_INDEX)
inclusive.
So NFP_MAX_MAC_INDEX (0xff) is a valid id.

In order for the error handling path to work correctly, the 'invalid'
value for 'ida_idx' should not be in the 0..NFP_MAX_MAC_INDEX range,
inclusive.

So set it to -1.

Fixes: 20cce8865098 ("nfp: flower: enable MAC address sharing for offloadable devs")
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Signed-off-by: Simon Horman <simon.horman@corigine.com>
Link: https://lore.kernel.org/r/20220218131535.100258-1-simon.horman@corigine.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/drivers/net/ethernet/netronome/nfp/flower/tunnel_conf.c b/drivers/net/ethernet/netronome/nfp/flower/tunnel_conf.c
index 0a326e0..cb43651 100644 (file)
--- a/drivers/net/ethernet/netronome/nfp/flower/tunnel_conf.c
+++ b/drivers/net/ethernet/netronome/nfp/flower/tunnel_conf.c
@@ -922,8 +922,8 @@ nfp_tunnel_add_shared_mac(struct nfp_app *app, struct net_device *netdev,
                          int port, bool mod)
 {
        struct nfp_flower_priv *priv = app->priv;
-       int ida_idx = NFP_MAX_MAC_INDEX, err;
        struct nfp_tun_offloaded_mac *entry;
+       int ida_idx = -1, err;
        u16 nfp_mac_idx = 0;
 
        entry = nfp_tunnel_lookup_offloaded_macs(app, netdev->dev_addr);
@@ -997,7 +997,7 @@ err_remove_hash:
 err_free_entry:
        kfree(entry);
 err_free_ida:
-       if (ida_idx != NFP_MAX_MAC_INDEX)
+       if (ida_idx != -1)
                ida_simple_remove(&priv->tun.mac_off_ids, ida_idx);
 
        return err;