queue-6.6/net-mscc-ocelot-add-missing-lock-protection-in-ocelo.patch

From d6267ee421be7d2d0767a6a694f99500c02080e1 Mon Sep 17 00:00:00 2001
From: Sasha Levin <sashal@kernel.org>
Date: Sun, 8 Feb 2026 22:56:02 +0000
Subject: net: mscc: ocelot: add missing lock protection in
 ocelot_port_xmit_inj()

From: Ziyi Guo <n7l8m4@u.northwestern.edu>

[ Upstream commit 026f6513c5880c2c89e38ad66bbec2868f978605 ]

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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/net/ethernet/mscc/ocelot_net.c | 12 ++++++++++--
 1 file changed, 10 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/mscc/ocelot_net.c b/drivers/net/ethernet/mscc/ocelot_net.c
index 84b3dcf1d2f5a..b516b4e1ed974 100644
--- 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;
-- 
2.51.0