linux-kernel - [PATCH 5.15 071/102] usb: typec: tcpci: Dont skip cleanup in .remove() on error

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Date:   Mon, 16 May 2022 21:36:45 +0200
From:   Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To:     linux-kernel@...r.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        stable@...r.kernel.org,
        Uwe Kleine-König 
        <u.kleine-koenig@...gutronix.de>,
        Heikki Krogerus <heikki.krogerus@...ux.intel.com>,
        Guenter Roeck <linux@...ck-us.net>
Subject: [PATCH 5.15 071/102] usb: typec: tcpci: Dont skip cleanup in .remove() on error

From: Uwe Kleine-König <u.kleine-koenig@...gutronix.de>

commit bbc126ae381cf0a27822c1f822d0aeed74cc40d9 upstream.

Returning an error value in an i2c remove callback results in an error
message being emitted by the i2c core, but otherwise it doesn't make a
difference. The device goes away anyhow and the devm cleanups are
called.

In this case the remove callback even returns early without stopping the
tcpm worker thread and various timers. A work scheduled on the work
queue, or a firing timer after tcpci_remove() returned probably results
in a use-after-free situation because the regmap and driver data were
freed. So better make sure that tcpci_unregister_port() is called even
if disabling the irq failed.

Also emit a more specific error message instead of the i2c core's
"remove failed (EIO), will be ignored" and return 0 to suppress the
core's warning.

This patch is (also) a preparation for making i2c remove callbacks
return void.

Fixes: 3ba76256fc4e ("usb: typec: tcpci: mask event interrupts when remove driver")
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@...gutronix.de>
Cc: stable <stable@...r.kernel.org>
Acked-by: Heikki Krogerus <heikki.krogerus@...ux.intel.com>
Reviewed-by: Guenter Roeck <linux@...ck-us.net>
Link: https://lore.kernel.org/r/20220502080456.21568-1-u.kleine-koenig@pengutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
---
 drivers/usb/typec/tcpm/tcpci.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/usb/typec/tcpm/tcpci.c
+++ b/drivers/usb/typec/tcpm/tcpci.c
@@ -877,7 +877,7 @@ static int tcpci_remove(struct i2c_clien
 	/* Disable chip interrupts before unregistering port */
 	err = tcpci_write16(chip->tcpci, TCPC_ALERT_MASK, 0);
 	if (err < 0)
-		return err;
+		dev_warn(&client->dev, "Failed to disable irqs (%pe)\n", ERR_PTR(err));

 	tcpci_unregister_port(chip->tcpci);