Re: Data corruption issue with splice() on 2.6.27.10

[Herbert Xu]

On Wed, Jan 07, 2009 at 01:22:05PM +0100, Willy Tarreau wrote:
>
> > diff --git a/net/core/skbuff.c b/net/core/skbuff.c
> > index 5110b35..4c080cd 100644
> > --- a/net/core/skbuff.c
> > +++ b/net/core/skbuff.c
> > @@ -73,17 +73,13 @@ static struct kmem_cache *skbuff_fclone_cache __read_mostly;
> >  static void sock_pipe_buf_release(struct pipe_inode_info *pipe,
> >  				  struct pipe_buffer *buf)
> >  {
> > -	struct sk_buff *skb = (struct sk_buff *) buf->private;
> > -
> > -	kfree_skb(skb);
> > +	put_page(buf->page);
> >  }
> >  
> >  static void sock_pipe_buf_get(struct pipe_inode_info *pipe,
> >  				struct pipe_buffer *buf)
> >  {
> > -	struct sk_buff *skb = (struct sk_buff *) buf->private;
> > -
> > -	skb_get(skb);
> > +	get_page(buf->page);
> >  }

Well this patch can only make it worse because not only are you
still ref counting skb->head with get_page, but you've also
completely removed the skb ref count which means that the corruption
can only occur sooner.

Cheers,
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