Commit b22b5142 authored May 10, 2023 by Uwe Kleine-König Committed by Greg Kroah-Hartman May 30, 2023

net: fec: Better handle pm_runtime_get() failing in .remove()



[ Upstream commit f816b9829b19394d318e01953aa3b2721bca040d ]

In the (unlikely) event that pm_runtime_get() (disguised as
pm_runtime_resume_and_get()) fails, the remove callback returned an
error early. The problem with this is that the driver core ignores the
error value and continues removing the device. This results in a
resource leak. Worse the devm allocated resources are freed and so if a
callback of the driver is called later the register mapping is already
gone which probably results in a crash.

Fixes: a31eda65 ("net: fec: fix clock count mis-match")
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Link: https://lore.kernel.org/r/20230510200020.1534610-1-u.kleine-koenig@pengutronix.de


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

parent 033297ef

drivers/net/ethernet/freescale/fec_main.c

+10 −3

Original line number	Diff line number	Diff line
		@@ -3769,7 +3769,9 @@ fec_drv_remove(struct platform_device *pdev)

		ret = pm_runtime_get_sync(&pdev->dev);
		if (ret < 0)
		return ret;
		dev_err(&pdev->dev,
		"Failed to resume device in remove callback (%pe)\n",
		ERR_PTR(ret));

		cancel_work_sync(&fep->tx_timeout_work);
		fec_ptp_stop(pdev);
		@@ -3782,8 +3784,13 @@ fec_drv_remove(struct platform_device *pdev)
		of_phy_deregister_fixed_link(np);
		of_node_put(fep->phy_node);

		/* After pm_runtime_get_sync() failed, the clks are still off, so skip
		* disabling them again.
		*/
		if (ret >= 0) {
		clk_disable_unprepare(fep->clk_ahb);
		clk_disable_unprepare(fep->clk_ipg);
		}
		pm_runtime_put_noidle(&pdev->dev);
		pm_runtime_disable(&pdev->dev);