From:   Toke =?utf-8?Q?H=C3=B8iland-J=C3=B8rgensen?= <toke@redhat.com>
To:     Alexander Duyck <alexander.duyck@gmail.com>, nbd@nbd.name
Cc:     alexander.duyck@gmail.com, davem@davemloft.net,
        edumazet@google.com, hawk@kernel.org, ilias.apalodimas@linaro.org,
        kuba@kernel.org, linux-kernel@vger.kernel.org,
        linyunsheng@huawei.com, lorenzo@kernel.org, netdev@vger.kernel.org,
        pabeni@redhat.com
Subject: Re: [net PATCH] skb: Do mix page pool and page referenced frags in GRO
In-Reply-To: <167475990764.1934330.11960904198087757911.stgit@localhost.localdomain>
References: <04e27096-9ace-07eb-aa51-1663714a586d@nbd.name>
 <167475990764.1934330.11960904198087757911.stgit@localhost.localdomain>
Date:   Thu, 26 Jan 2023 20:14:02 +0100
Message-ID: <87tu0dkt1h.fsf@toke.dk>
MIME-Version: 1.0
Content-Type: text/plain
Precedence: bulk

Alexander Duyck <alexander.duyck@gmail.com> writes:

> From: Alexander Duyck <alexanderduyck@fb.com>
>
> GSO should not merge page pool recycled frames with standard reference
> counted frames. Traditionally this didn't occur, at least not often.
> However as we start looking at adding support for wireless adapters there
> becomes the potential to mix the two due to A-MSDU repartitioning frames in
> the receive path. There are possibly other places where this may have
> occurred however I suspect they must be few and far between as we have not
> seen this issue until now.
>
> Fixes: 53e0961da1c7 ("page_pool: add frag page recycling support in page pool")
> Reported-by: Felix Fietkau <nbd@nbd.name>
> Signed-off-by: Alexander Duyck <alexanderduyck@fb.com>

I know I'm pattern matching a bit crudely here, but we recently had
another report where doing a get_page() on skb->head didn't seem to be
enough; any chance they might be related?

See: https://lore.kernel.org/r/Y9BfknDG0LXmruDu@JNXK7M3

-Toke