usb: gadget: ether: Fix race between gether_disconnect and rx_submit

On spin lock release in rx_submit, gether_disconnect get a chance to
run, it makes port_usb NULL, rx_submit access NULL port USB, hence null
pointer crash.

Fixed by releasing the lock in rx_submit after port_usb is used.

Fixes: 2b3d942c48 ("usb ethernet gadget: split out network core")
Cc: <stable@vger.kernel.org>
Signed-off-by: Kiruthika Varadarajan <Kiruthika.Varadarajan@harman.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
This commit is contained in:
Kiruthika Varadarajan 2019-06-18 08:39:06 +00:00 committed by Felipe Balbi
parent e70b3f5da0
commit d29fcf7078

View File

@ -186,11 +186,12 @@ rx_submit(struct eth_dev *dev, struct usb_request *req, gfp_t gfp_flags)
out = dev->port_usb->out_ep;
else
out = NULL;
spin_unlock_irqrestore(&dev->lock, flags);
if (!out)
{
spin_unlock_irqrestore(&dev->lock, flags);
return -ENOTCONN;
}
/* Padding up to RX_EXTRA handles minor disagreements with host.
* Normally we use the USB "terminate on short read" convention;
@ -214,6 +215,7 @@ rx_submit(struct eth_dev *dev, struct usb_request *req, gfp_t gfp_flags)
if (dev->port_usb->is_fixed)
size = max_t(size_t, size, dev->port_usb->fixed_out_len);
spin_unlock_irqrestore(&dev->lock, flags);
skb = __netdev_alloc_skb(dev->net, size + NET_IP_ALIGN, gfp_flags);
if (skb == NULL) {