[RFC] net: usb: gl620a: check for rx buffer overflow

[RFC] net: usb: gl620a: check for rx buffer overflow

[Oliver Neukum]

The driver checks for a single package overflowing
maximum size. That needs to be done, but it is not
enough. As a single transmission can contain a high
number of packets, we also need to check whether
the aggregate of messages in itself short enough
overflow the buffer.
That is easiest done by checking that the current
packet does not overflow the buffer.

Signed-off-by: Oliver Neukum <oneukum@suse.com>
---
 drivers/net/usb/gl620a.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/net/usb/gl620a.c b/drivers/net/usb/gl620a.c
index 0bfa37c14059..3d3eb1706e2a 100644
--- a/drivers/net/usb/gl620a.c
+++ b/drivers/net/usb/gl620a.c
@@ -104,6 +104,10 @@ static int genelink_rx_fixup(struct usbnet *dev, struct sk_buff *skb)
 			return 0;
 		}
 
+		/* we also need to check for overflowing the buffer */
+		if (size > skb->len)
+			return 0;
+
 		// allocate the skb for the individual packet
 		gl_skb = alloc_skb(size, GFP_ATOMIC);
 		if (gl_skb) {
-- 
2.53.0