net: ethernet: mtk_ppe: add RCU lock around dev_fill_forward_path

[ Upstream commit 62c30c5 ]

Ensure ndo_fill_forward_path() is called with RCU lock held.

Fixes: 2830e31 ("net: ethernet: mtk-ppe: fix traffic offload with bridged wlan")
Signed-off-by: Qingfang Deng <dqfext@gmail.com>
Link: https://patch.msgid.link/20250814012559.3705-1-dqfext@gmail.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

Author: LGA1150

drivers/net/ethernet/mediatek/mtk_ppe_offload.c

@@ -101,7 +101,9 @@ mtk_flow_get_wdma_info(struct net_device *dev, const u8 *addr, struct mtk_wdma_i
 	if (!IS_ENABLED(CONFIG_NET_MEDIATEK_SOC_WED))
 		return -1;
 
+	rcu_read_lock();
 	err = dev_fill_forward_path(dev, addr, &stack);
+	rcu_read_unlock();
 	if (err)
 		return err;