Re: Regression associated with commit c8628155ece3 - "tcp: reduceout_of_order memory use"

[Eric Dumazet]

On Fri, 2012-08-24 at 10:58 -0500, Larry Finger wrote:
> On 08/24/2012 10:19 AM, David Miller wrote:
> >
> > This looks like full-on data corruption to me.
> 
> I agree. The question is why does it happen with r8712u, and only after the 
> commit in the subject. Drivers for other devices that I have are OK. Thus far, I 
> have tested b43, rtl8187, ath9k_htc, and rtl8192cu. To my knowledge, there are 
> no reports posted for this bug with any other device.

bugs can sit unnoticed, and one change somewhere can uncover them.

Really this driver must have a bug, if not half a dozen of bugs.

For example this sequence of code is a clear bug :

sub_skb = dev_alloc_skb(nSubframe_Length + 12); 
skb_reserve(sub_skb, 12);


Also the free_recv_skb_queue looks really suspect to me

What the hell is doing recv_tasklet() I really wonder.

This code, combined with the skb_clone() in recvbuf2recvframe()
can clearly reuse an skb passed to upper stacks.


queueing one skb in free_recv_skb_queue should be done
only if no clone of this skb exist somewhere.

Please someone fix this buggy driver.


--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/