can: j1939: j1939_local_ecu_get(): undo increment when j1939_local_ecu_get() fails

Since j1939_sk_bind() and j1939_sk_release() call j1939_local_ecu_put()
when J1939_SOCK_BOUND was already set, but the error handling path for
j1939_sk_bind() will not set J1939_SOCK_BOUND when j1939_local_ecu_get()
fails, j1939_local_ecu_get() needs to undo priv->ents[sa].nusers++ when
j1939_local_ecu_get() returns an error.

Fixes: 9d71dd0c7009 ("can: add support of SAE J1939 protocol")
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Tested-by: Oleksij Rempel <o.rempel@pengutronix.de>
Acked-by: Oleksij Rempel <o.rempel@pengutronix.de>
Link: https://patch.msgid.link/e7f80046-4ff7-4ce2-8ad8-7c3c678a42c9@I-love.SAKURA.ne.jp
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

diff --git a/net/can/j1939/bus.c b/net/can/j1939/bus.c
index 39844f14eed86290dacb3cf17ed2141f1d0062fd..797719cb227ec59ace288f1e146d08f2984207ef 100644 (file)
--- a/net/can/j1939/bus.c
+++ b/net/can/j1939/bus.c
@@ -290,8 +290,11 @@ int j1939_local_ecu_get(struct j1939_priv *priv, name_t name, u8 sa)
        if (!ecu)
                ecu = j1939_ecu_create_locked(priv, name);
        err = PTR_ERR_OR_ZERO(ecu);
-       if (err)
+       if (err) {
+               if (j1939_address_is_unicast(sa))
+                       priv->ents[sa].nusers--;
                goto done;
+       }
 
        ecu->nusers++;
        /* TODO: do we care if ecu->addr != sa? */