Subject: re: net: Micrel KSZ8841/2 PCI Ethernet driver

From: Ben Hutchings <[email-masked]>
Date: Wed, 18 Apr 2012 15:13:14 +0100

On Wed, 2012-04-18 at 09:47 +0300, Dan Carpenter wrote:
> Hello Tristram,
> 
> I was going through some old stuff and I had a question about ksz884x.c.
> 
> The patch 8ca86fd83eae: "net: Micrel KSZ8841/2 PCI Ethernet driver" 
> from Feb 8, 2010, leads to the following warning:
> drivers/net/ethernet/micrel/ksz884x.c:5678 netdev_set_mac_address()
> 	 error: memcpy() 'mac->sa_data' too small (14 vs 32)
> 
>   5663  static int netdev_set_mac_address(struct net_device *dev, void *addr)
>   5664  {
>   5665          struct dev_priv *priv = netdev_priv(dev);
>   5666          struct dev_info *hw_priv = priv->adapter;
>   5667          struct ksz_hw *hw = &hw_priv->hw;
>   5668          struct sockaddr *mac = addr;
>   5669          uint interrupt;
>   5670  
>   5671          if (priv->port.first_port > 0)
>   5672                  hw_del_addr(hw, dev->dev_addr);
>   5673          else {
>   5674                  hw->mac_override = 1;
>   5675                  memcpy(hw->override_addr, mac->sa_data, ETH_ALEN);
>   5676          }
>   5677  
>   5678          memcpy(dev->dev_addr, mac->sa_data, MAX_ADDR_LEN);
>                                       ^^^^^^^^^^^^
> This has only 14 bytes so we're copying bogus data from beyond the end
> of the struct into dev->dev_addr.

The correct length is ETH_ALEN, as for the previous memcpy().

Ben.

-- 
Ben Hutchings, Staff Engineer, Solarflare
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