This is a note to let you know that I've just added the patch titled net: dsa: destroy the phylink instance on any error in dsa_slave_phy_setup to the 4.19-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-dsa-destroy-the-phylink-instance-on-any-error-in-dsa_slave_phy_setup.patch and it can be found in the queue-4.19 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From 6a52e73368038f47f6618623d75061dc263b26ae Mon Sep 17 00:00:00 2001 From: Vladimir Oltean <vladimir.oltean@xxxxxxx> Date: Tue, 14 Sep 2021 16:43:31 +0300 Subject: net: dsa: destroy the phylink instance on any error in dsa_slave_phy_setup From: Vladimir Oltean <vladimir.oltean@xxxxxxx> commit 6a52e73368038f47f6618623d75061dc263b26ae upstream. DSA supports connecting to a phy-handle, and has a fallback to a non-OF based method of connecting to an internal PHY on the switch's own MDIO bus, if no phy-handle and no fixed-link nodes were present. The -ENODEV error code from the first attempt (phylink_of_phy_connect) is what triggers the second attempt (phylink_connect_phy). However, when the first attempt returns a different error code than -ENODEV, this results in an unbalance of calls to phylink_create and phylink_destroy by the time we exit the function. The phylink instance has leaked. There are many other error codes that can be returned by phylink_of_phy_connect. For example, phylink_validate returns -EINVAL. So this is a practical issue too. Fixes: aab9c4067d23 ("net: dsa: Plug in PHYLINK support") Signed-off-by: Vladimir Oltean <vladimir.oltean@xxxxxxx> Reviewed-by: Florian Fainelli <f.fainelli@xxxxxxxxx> Reviewed-by: Russell King (Oracle) <rmk+kernel@xxxxxxxxxxxxxxx> Link: https://lore.kernel.org/r/20210914134331.2303380-1-vladimir.oltean@xxxxxxx Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- net/dsa/slave.c | 12 +++++------- 1 file changed, 5 insertions(+), 7 deletions(-) --- a/net/dsa/slave.c +++ b/net/dsa/slave.c @@ -1226,13 +1226,11 @@ static int dsa_slave_phy_setup(struct ne * use the switch internal MDIO bus instead */ ret = dsa_slave_phy_connect(slave_dev, dp->index); - if (ret) { - netdev_err(slave_dev, - "failed to connect to port %d: %d\n", - dp->index, ret); - phylink_destroy(dp->pl); - return ret; - } + } + if (ret) { + netdev_err(slave_dev, "failed to connect to PHY: %pe\n", + ERR_PTR(ret)); + phylink_destroy(dp->pl); } return ret; Patches currently in stable-queue which might be from vladimir.oltean@xxxxxxx are queue-4.19/spi-spi-fsl-dspi-fix-issue-with-uninitialized-dma_sl.patch queue-4.19/net-dsa-destroy-the-phylink-instance-on-any-error-in-dsa_slave_phy_setup.patch