netdev - Re: [PATCH net] tcp: do not recycle cloned skbs

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Message-ID: <CANn89i+2OuujyrwxR_n=VBwNHABai3B+0tti_jMkMU4UD1Wn8A@mail.gmail.com>
Date:   Wed, 15 May 2019 09:26:54 -0700
From:   Eric Dumazet <edumazet@...gle.com>
To:     David Miller <davem@...emloft.net>
Cc:     netdev <netdev@...r.kernel.org>,
        Willem de Bruijn <willemb@...gle.com>,
        Eric Dumazet <eric.dumazet@...il.com>
Subject: Re: [PATCH net] tcp: do not recycle cloned skbs

On Wed, May 15, 2019 at 9:24 AM David Miller <davem@...emloft.net> wrote:
>
> From: Eric Dumazet <edumazet@...gle.com>
> Date: Wed, 15 May 2019 09:10:15 -0700
>
> > It is illegal to change arbitrary fields in skb_shared_info if the
> > skb is cloned.
> >
> > Before calling skb_zcopy_clear() we need to ensure this rule,
> > therefore we need to move the test from sk_stream_alloc_skb()
> > to sk_wmem_free_skb()
> >
> > Fixes: 4f661542a402 ("tcp: fix zerocopy and notsent_lowat issues")
> > Signed-off-by: Eric Dumazet <edumazet@...gle.com>
> > Diagnosed-by: Willem de Bruijn <willemb@...gle.com>
>
> Applied and queued up for -stable.

Note the patch targets current net tree, but does not need to be
backported to older kernel versions
(4f661542a402 is only in upcoming 5.2)

Thanks !