[PATCH] libertas if_usb: Fix crash on 64-bit machines

[David Miller]

From: David Woodhouse <dwmw2 at infradead.org>
Date: Fri, 30 Oct 2009 17:45:14 +0000

> On a 64-bit kernel, skb->tail is an offset, not a pointer. The libertas
> usb driver passes it to usb_fill_bulk_urb() anyway, causing interesting
> crashes. Fix that by using skb->data instead.
> 
> This highlights a problem with usb_fill_bulk_urb(). It doesn't notice
> when dma_map_single() fails and return the error to its caller as it
> should. In fact it _can't_ currently return the error, since it returns
> void.
> 
> So this problem was showing up only at unmap time, after we'd already
> suffered memory corruption by doing DMA to a bogus address.
> 
> Signed-off-by: David Woodhouse <David.Woodhouse at intel.com>
> Cc: stable at kernel.org

Acked-by: David S. Miller <davem at davemloft.net>