Commit 56b786d8 authored by Dongliang Mu's avatar Dongliang Mu Committed by David S. Miller
Browse files

net: usb: fix possible use-after-free in smsc75xx_bind 



The commit 46a8b29c ("net: usb: fix memory leak in smsc75xx_bind")
fails to clean up the work scheduled in smsc75xx_reset->
smsc75xx_set_multicast, which leads to use-after-free if the work is
scheduled to start after the deallocation. In addition, this patch
also removes a dangling pointer - dev->data[0].

This patch calls cancel_work_sync to cancel the scheduled work and set
the dangling pointer to NULL.

Fixes: 46a8b29c ("net: usb: fix memory leak in smsc75xx_bind")
Signed-off-by: default avatarDongliang Mu <mudongliangabcd@gmail.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 8f269102

drivers/net/usb/smsc75xx.c

+6 −4
Original line number Diff line number Diff line
@@ -1483,7 +1483,7 @@ static int smsc75xx_bind(struct usbnet *dev, struct usb_interface *intf) 
	ret = smsc75xx_wait_ready(dev, 0);

	if (ret < 0) {

		netdev_warn(dev->net, "device not ready in smsc75xx_bind\n");

		goto err;

		goto free_pdata;

	}



	smsc75xx_init_mac_address(dev);
@@ -1492,7 +1492,7 @@ static int smsc75xx_bind(struct usbnet *dev, struct usb_interface *intf) 
	ret = smsc75xx_reset(dev);

	if (ret < 0) {

		netdev_warn(dev->net, "smsc75xx_reset error %d\n", ret);

		goto err;

		goto cancel_work;

	}



	dev->net->netdev_ops = &smsc75xx_netdev_ops;
@@ -1503,8 +1503,11 @@ static int smsc75xx_bind(struct usbnet *dev, struct usb_interface *intf) 
	dev->net->max_mtu = MAX_SINGLE_PACKET_SIZE;

	return 0;



err:

cancel_work:

	cancel_work_sync(&pdata->set_multicast);

free_pdata:

	kfree(pdata);

	dev->data[0] = 0;

	return ret;

}
@@ -1515,7 +1518,6 @@ static void smsc75xx_unbind(struct usbnet *dev, struct usb_interface *intf) 
		cancel_work_sync(&pdata->set_multicast);

		netif_dbg(dev, ifdown, dev->net, "free pdata\n");

		kfree(pdata);

		pdata = NULL;

		dev->data[0] = 0;

	}

}