Re: [PATCH v2] net: usb: lan78xx: Limit packet length to skb->len

[Greg KH]

On Fri, Mar 17, 2023 at 06:36:06PM +0100, Szymon Heidrich wrote:
> Packet length retrieved from descriptor may be larger than
> the actual socket buffer length. In such case the cloned
> skb passed up the network stack will leak kernel memory contents.
> 
> Additionally prevent integer underflow when size is less than
> ETH_FCS_LEN.
> 
> Fixes: 55d7de9de6c3 ("Microchip's LAN7800 family USB 2/3 to 10/100/1000 Ethernet device driver")
> Signed-off-by: Szymon Heidrich <szymon.heidrich@xxxxxxxxx>
> Reported-by: kernel test robot <lkp@xxxxxxxxx>

the test robot did not report the fact that the packet length needed to
be limited :(