Date:   Thu, 23 Feb 2023 14:03:17 +0100
From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     Vladimir Oltean <olteanv@gmail.com>
Cc:     Kurt Kanzenbach <kurt@linutronix.de>,
        Sasha Levin <sashal@kernel.org>,
        Vladimir Oltean <vladimir.oltean@nxp.com>,
        netdev@vger.kernel.org,
        Vinicius Costa Gomes <vinicius.gomes@intel.com>,
        Jamal Hadi Salim <jhs@mojatatu.com>,
        Cong Wang <xiyou.wangcong@gmail.com>,
        Jiri Pirko <jiri@resnulli.us>,
        "David S. Miller" <davem@davemloft.net>,
        Eric Dumazet <edumazet@google.com>,
        Jakub Kicinski <kuba@kernel.org>,
        Paolo Abeni <pabeni@redhat.com>,
        Voon Weifeng <weifeng.voon@intel.com>,
        linux-kernel@vger.kernel.org,
        Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Subject: Re: [PATCH v2 net 2/2] net/sched: taprio: make qdisc_leaf() see the
 per-netdev-queue pfifo child qdiscs
Message-ID: <Y/dkFcqSdLK+jEMK@kroah.com>
References: <20220915100802.2308279-1-vladimir.oltean@nxp.com>
 <20220915100802.2308279-3-vladimir.oltean@nxp.com>
 <874jrdvluv.fsf@kurt>
 <20230222142507.hapqjfhswhlq42ay@skbuf>
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On Wed, Feb 22, 2023 at 04:25:07PM +0200, Vladimir Oltean wrote:
> +Greg, Sasha.

Hint, in the future, please cc: stable@vger.kernel.org with stable
kernel requests, I know I don't see stuff that isn't cc:ed there
normally when working on that tree.

> 
> Hi Kurt,
> 
> On Wed, Feb 22, 2023 at 03:03:04PM +0100, Kurt Kanzenbach wrote:
> > This commit was backported to v5.15-LTS which results in NULL pointer
> > dereferences e.g., when attaching an ETF child qdisc to taprio.
> > 
> > From what I can see is, that the issue was reported back then and this
> > commit was reverted [1]. However, the revert didn't make it into
> > v5.15-LTS? Is there a reason for it? I'm testing 5.15.94-rt59 here.
> > 
> > Thanks,
> > Kurt
> > 
> > [1] - https://lore.kernel.org/all/20221004220100.1650558-1-vladimir.oltean@nxp.com/
> 
> You are right; the patchwork-bot clearly says that the revert was
> applied to net.git as commit af7b29b1deaa ("Revert "net/sched: taprio:
> make qdisc_leaf() see the per-netdev-queue pfifo child qdiscs""), but
> the revert never made it to stable.
> 
> OTOH, the original patch did make it to, and still is in, linux-stable.
> I have backport notification emails of the original to 5.4, 5.10, 5.15, 5.19.
> 
> Greg, Sasha, can you please pick up and backport commit af7b29b1deaa
> ("Revert "net/sched: taprio: make qdisc_leaf() see the per-netdev-queue
> pfifo child qdiscs"") to the currently maintained stable kernels?

Now queued up, thanks.

greg k-h