Re: [PATCH net v3] net: esp: fix bad handling of pages from page_pool

[Steffen Klassert <steffen.klassert@secunet.com>]

On Fri, Mar 08, 2024 at 05:26:00PM +0200, Dragos Tatulea wrote:
> When the skb is reorganized during esp_output (!esp->inline), the pages
> coming from the original skb fragments are supposed to be released back
> to the system through put_page. But if the skb fragment pages are
> originating from a page_pool, calling put_page on them will trigger a
> page_pool leak which will eventually result in a crash.
> 
> This leak can be easily observed when using CONFIG_DEBUG_VM and doing
> ipsec + gre (non offloaded) forwarding:

...

> The suggested fix is to introduce a new wrapper (skb_page_unref) that
> covers page refcounting for page_pool pages as well.
> 
> Cc: stable@vger.kernel.org
> Fixes: 6a5bcd84e886 ("page_pool: Allow drivers to hint on SKB recycling")
> Reported-and-tested-by: Anatoli N.Chechelnickiy <Anatoli.Chechelnickiy@m.interpipe.biz>
> Reported-by: Ian Kumlien <ian.kumlien@gmail.com>
> Link: https://lore.kernel.org/netdev/CAA85sZvvHtrpTQRqdaOx6gd55zPAVsqMYk_Lwh4Md5knTq7AyA@mail.gmail.com
> Signed-off-by: Dragos Tatulea <dtatulea@nvidia.com>
> Reviewed-by: Mina Almasry <almasrymina@google.com>
> Reviewed-by: Jakub Kicinski <kuba@kernel.org>

Applied to the ipsec tree, thanks a lot!