net: mscc: ocelot: add missing lock protection in ocelot_port_xmit_inj()

ocelot_port_xmit_inj() calls ocelot_can_inject() and
ocelot_port_inject_frame() without holding the injection group lock.
Both functions contain lockdep_assert_held() for the injection lock,
and the correct caller felix_port_deferred_xmit() properly acquires
the lock using ocelot_lock_inj_grp() before calling these functions.

Add ocelot_lock_inj_grp()/ocelot_unlock_inj_grp() around the register
injection path to fix the missing lock protection. The FDMA path is not
affected as it uses its own locking mechanism.

Fixes: c5e12ac3beb0 ("net: mscc: ocelot: serialize access to the injection/extraction groups")
Signed-off-by: Ziyi Guo <n7l8m4@u.northwestern.edu>
Reviewed-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Link: https://patch.msgid.link/20260208225602.1339325-4-n7l8m4@u.northwestern.edu
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/drivers/net/ethernet/mscc/ocelot_net.c b/drivers/net/ethernet/mscc/ocelot_net.c
index a7966c174b2e22e62329416e1b0f7f36f17cc33f..1b82693204640d32abece97ade4710ad1a0c355d 100644 (file)
--- a/drivers/net/ethernet/mscc/ocelot_net.c
+++ b/drivers/net/ethernet/mscc/ocelot_net.c
@@ -597,14 +597,22 @@ static netdev_tx_t ocelot_port_xmit_inj(struct sk_buff *skb,
        int port = priv->port.index;
        u32 rew_op = 0;
 
-       if (!ocelot_can_inject(ocelot, 0))
+       ocelot_lock_inj_grp(ocelot, 0);
+
+       if (!ocelot_can_inject(ocelot, 0)) {
+               ocelot_unlock_inj_grp(ocelot, 0);
                return NETDEV_TX_BUSY;
+       }
 
-       if (!ocelot_xmit_timestamp(ocelot, port, skb, &rew_op))
+       if (!ocelot_xmit_timestamp(ocelot, port, skb, &rew_op)) {
+               ocelot_unlock_inj_grp(ocelot, 0);
                return NETDEV_TX_OK;
+       }
 
        ocelot_port_inject_frame(ocelot, port, 0, rew_op, skb);
 
+       ocelot_unlock_inj_grp(ocelot, 0);
+
        consume_skb(skb);
 
        return NETDEV_TX_OK;