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From:   Ulf Hansson <ulf.hansson@linaro.org>
Date:   Wed, 5 Sep 2018 08:30:29 +0200
Message-ID: <CAPDyKFo1vwg43Nzaco4-vfmDp9RShdh4wcyM5UrdFzd89qaNcA@mail.gmail.com>
Subject: Re: [PATCH v2 4/9] mmc: meson-mx-sdio: fix OF child-node lookup
To:     Johan Hovold <johan@kernel.org>
Cc:     Rob Herring <robh+dt@kernel.org>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Frank Rowand <frowand.list@gmail.com>,
        DTML <devicetree@vger.kernel.org>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        stable <stable@vger.kernel.org>,
        Carlo Caione <carlo@endlessm.com>,
        Martin Blumenstingl <martin.blumenstingl@googlemail.com>
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On 4 September 2018 at 14:54, Johan Hovold <johan@kernel.org> wrote:
> On Mon, Aug 27, 2018 at 04:44:44PM +0200, Ulf Hansson wrote:
>> On 27 August 2018 at 10:21, Johan Hovold <johan@kernel.org> wrote:
>> > Use the new of_get_compatible_child() helper to lookup the slot child
>> > node instead of using of_find_compatible_node(), which searches the
>> > entire tree from a given start node and thus can return an unrelated
>> > (i.e. non-child) node.
>> >
>> > This also addresses a potential use-after-free (e.g. after probe
>> > deferral) as the tree-wide helper drops a reference to its first
>> > argument (i.e. the node of the device being probed).
>> >
>> > While at it, also fix up the related slot-node reference leak.
>> >
>> > Fixes: ed80a13bb4c4 ("mmc: meson-mx-sdio: Add a driver for the Amlogic Meson8 and Meson8b SoCs")
>> > Cc: stable <stable@vger.kernel.org>     # 4.15
>> > Cc: Carlo Caione <carlo@endlessm.com>
>> > Cc: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
>> > Cc: Ulf Hansson <ulf.hansson@linaro.org>
>> > Acked-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
>> > Signed-off-by: Johan Hovold <johan@kernel.org>
>>
>> Acked-by: Ulf Hansson <ulf.hansson@linaro.org>
>
> Thanks for the ack. Rob's gotten the helper into -rc2, so feel free to
> pick this one up directly to whichever mmc branch you prefer. I've been
> able to trigger crashes after probe deferrals due to the use-after-free,
> but this seems unlikely to be exploitable.

Applied for fixes, thanks!

Kind regards
Uffe