[Devel] Re: [PATCH] Copy mac_len in skb_clone() as well

[David Miller]

From: Kirill Korotaev <dev at sw.ru>
Date: Thu, 15 Mar 2007 13:33:12 +0300

> David Miller wrote:
> > From: Alexey Dobriyan <adobriyan at sw.ru>
> > Date: Wed, 14 Mar 2007 16:07:11 +0300
> > 
> > 
> >>ANK says: "It is rarely used, that's wy it was not noticed.
> >>But in the places, where it is used, it should be disaster."
> >>
> >>Signed-off-by: Alexey Dobriyan <adobriyan at sw.ru>
> > 
> > 
> > Applied.
> > 
> > What bug triggered that helped you discover this?  Or is it
> > merely from a code audit?
> Ohhh, it is a fairy-tale to tell the truth :)
> We had some unexplainable problems with java application in OpenVZ kernel.
> It didn't work sometimes, but worked fine (!) with CONFIG_SLAB_DEBUG.
> Alexey blamed java :), but ...
> Then we found that poising one of the bits in slab cache was curing it.
> After that we found that the problem is related to fclone cache.
> And then we found that not all the fields are initialized during cloning.
> The bug was related to our own skb->field we introduced,
> but we analyzed the code and found this as well.

Thanks for the detailed information.