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

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The commit 46a8b29c6306 ("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: 46a8b29c6306 ("net: usb: fix memory leak in smsc75xx_bind")
Signed-off-by: Dongliang Mu <mudongliangabcd@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Dongliang Mu 2021-06-16 10:48:33 +08:00 committed by David S. Miller
parent 8f269102ba
commit 56b786d866
1 changed files with 6 additions and 4 deletions
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10
drivers/net/usb/smsc75xx.c
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@ -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;
}
}