mwifiex: don't do unbalanced free()'ing in cleanup_if()

The cleanup_if() callback is the inverse of init_if(). We allocate our
'card' interface structure in the probe() function, but we free it in
cleanup_if(). That gives a few problems:
(a) we leak this memory if probe() fails before we reach init_if()
(b) we can't safely utilize 'card' after cleanup_if() -- namely, in
    remove() or suspend(), both of which might race with the cleanup
    paths in our asynchronous FW initialization path

Solution: just use devm_kzalloc(), which will free this structure
properly when the device is removed -- and drop the set_drvdata(...,
NULL), since the driver core does this for us. This also removes the
temptation to use drvdata == NULL as a hack for checking if the device
has been "cleaned up."

I *do* leave the set_drvdata(..., NULL) for the hacky SDIO
mwifiex_recreate_adapter(), since the device core won't be able to clear
that one for us.

Signed-off-by: Brian Norris <briannorris@chromium.org>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>

1 files changed, 1 insertions, 6 deletions

diff --git a/drivers/net/wireless/marvell/mwifiex/usb.c b/drivers/net/wireless/marvell/mwifiex/usb.c
index 73eb0846db21..57ed834ba296 100644
--- a/drivers/net/wireless/marvell/mwifiex/usb.c
+++ b/drivers/net/wireless/marvell/mwifiex/usb.c
@@ -382,7 +382,7 @@ static int mwifiex_usb_probe(struct usb_interface *intf,
 	struct usb_card_rec *card;
 	u16 id_vendor, id_product, bcd_device, bcd_usb;
 
-	card = kzalloc(sizeof(struct usb_card_rec), GFP_KERNEL);
+	card = devm_kzalloc(&intf->dev, sizeof(*card), GFP_KERNEL);
 	if (!card)
 		return -ENOMEM;
 
@@ -480,7 +480,6 @@ static int mwifiex_usb_probe(struct usb_interface *intf,
 	if (ret) {
 		pr_err("%s: mwifiex_add_card failed: %d\n", __func__, ret);
 		usb_reset_device(udev);
-		kfree(card);
 		return ret;
 	}
 
@@ -630,11 +629,7 @@ static void mwifiex_usb_disconnect(struct usb_interface *intf)
 		    "%s: removing card\n", __func__);
 	mwifiex_remove_card(adapter, &add_remove_card_sem);
 
-	usb_set_intfdata(intf, NULL);
 	usb_put_dev(interface_to_usbdev(intf));
-	kfree(card);
-
-	return;
 }
 
 static struct usb_driver mwifiex_usb_driver = {