Commit 96e056ff authored Jul 17, 2025 by Ma Ke Committed by Jakub Kicinski Jul 18, 2025

dpaa2-switch: Fix device reference count leak in MAC endpoint handling



The fsl_mc_get_endpoint() function uses device_find_child() for
localization, which implicitly calls get_device() to increment the
device's reference count before returning the pointer. However, the
caller dpaa2_switch_port_connect_mac() fails to properly release this
reference in multiple scenarios. We should call put_device() to
decrement reference count properly.

As comment of device_find_child() says, 'NOTE: you will need to drop
the reference with put_device() after use'.

Found by code review.

Cc: stable@vger.kernel.org
Fixes: 84cba729 ("dpaa2-switch: integrate the MAC endpoint support")
Signed-off-by: Ma Ke <make24@iscas.ac.cn>
Tested-by: Ioana Ciornei <ioana.ciornei@nxp.com>
Reviewed-by: Ioana Ciornei <ioana.ciornei@nxp.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://patch.msgid.link/20250717022309.3339976-3-make24@iscas.ac.cn


Signed-off-by: Jakub Kicinski <kuba@kernel.org>

parent ee9f3a81

drivers/net/ethernet/freescale/dpaa2/dpaa2-switch.c

+12 −3

Original line number	Diff line number	Diff line
		@@ -1448,12 +1448,19 @@ static int dpaa2_switch_port_connect_mac(struct ethsw_port_priv *port_priv)
		if (PTR_ERR(dpmac_dev) == -EPROBE_DEFER)
		return PTR_ERR(dpmac_dev);

		if (IS_ERR(dpmac_dev) \|\| dpmac_dev->dev.type != &fsl_mc_bus_dpmac_type)
		if (IS_ERR(dpmac_dev))
		return 0;

		if (dpmac_dev->dev.type != &fsl_mc_bus_dpmac_type) {
		err = 0;
		goto out_put_device;
		}

		mac = kzalloc(sizeof(*mac), GFP_KERNEL);
		if (!mac)
		return -ENOMEM;
		if (!mac) {
		err = -ENOMEM;
		goto out_put_device;
		}

		mac->mc_dev = dpmac_dev;
		mac->mc_io = port_priv->ethsw_data->mc_io;
		@@ -1483,6 +1490,8 @@ static int dpaa2_switch_port_connect_mac(struct ethsw_port_priv *port_priv)
		dpaa2_mac_close(mac);
		err_free_mac:
		kfree(mac);
		out_put_device:
		put_device(&dpmac_dev->dev);
		return err;
		}