Patch "net: fec: Better handle pm_runtime_get() failing in .remove()" has been added to the 6.1-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

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

to the 6.1-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     net-fec-better-handle-pm_runtime_get-failing-in-.rem.patch
and it can be found in the queue-6.1 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit 3c5b3b13b4aa4ee7c98f6f00f8a6834f9ce65dae
Author: Uwe Kleine-König <u.kleine-koenig@xxxxxxxxxxxxxx>
Date:   Wed May 10 22:00:20 2023 +0200

    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: a31eda65ba21 ("net: fec: fix clock count mis-match")
    Signed-off-by: Uwe Kleine-König <u.kleine-koenig@xxxxxxxxxxxxxx>
    Reviewed-by: Andrew Lunn <andrew@xxxxxxx>
    Link: https://lore.kernel.org/r/20230510200020.1534610-1-u.kleine-koenig@xxxxxxxxxxxxxx
    Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx>
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/drivers/net/ethernet/freescale/fec_main.c b/drivers/net/ethernet/freescale/fec_main.c
index 6f914180f4797..33226a22d8a4a 100644
--- a/drivers/net/ethernet/freescale/fec_main.c
+++ b/drivers/net/ethernet/freescale/fec_main.c
@@ -4168,9 +4168,11 @@ fec_drv_remove(struct platform_device *pdev)
 	struct device_node *np = pdev->dev.of_node;
 	int ret;
 
-	ret = pm_runtime_resume_and_get(&pdev->dev);
+	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);
@@ -4183,8 +4185,13 @@ fec_drv_remove(struct platform_device *pdev)
 		of_phy_deregister_fixed_link(np);
 	of_node_put(fep->phy_node);
 
-	clk_disable_unprepare(fep->clk_ahb);
-	clk_disable_unprepare(fep->clk_ipg);
+	/* 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);