[PATCH 3.19.y-ckt 067/251] staging: vt6655: device_rx_srv check sk_buff is NULL

[Kamal Mostafa]

3.19.8-ckt4 -stable review patch.  If anyone has any objections, please let me know.

------------------

From: Malcolm Priestley <tvboxspy at gmail.com>

commit b5eeed8cb6097c8ea660b6598d36fdbb94065a22 upstream.

There is a small chance that pRD->pRDInfo->skb could go NULL
while the interrupt is processing.

Put NULL check on loop to break out.

Signed-off-by: Malcolm Priestley <tvboxspy at gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh at linuxfoundation.org>
Signed-off-by: Kamal Mostafa <kamal at canonical.com>
---
 drivers/staging/vt6655/device_main.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/staging/vt6655/device_main.c b/drivers/staging/vt6655/device_main.c
index b95e915..fea0214 100644
--- a/drivers/staging/vt6655/device_main.c
+++ b/drivers/staging/vt6655/device_main.c
@@ -851,6 +851,10 @@ static int device_rx_srv(struct vnt_private *pDevice, unsigned int uIdx)
 	     pRD = pRD->next) {
 		if (works++ > 15)
 			break;
+
+		if (!pRD->pRDInfo->skb)
+			break;
+
 		if (vnt_receive_frame(pDevice, pRD)) {
 			if (!device_alloc_rx_buf(pDevice, pRD)) {
 				dev_err(&pDevice->pcid->dev,
-- 
1.9.1