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Date:   Tue, 12 Jan 2021 13:10:23 +0100
From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     Pintu Agarwal <pintu.ping@gmail.com>
Cc:     open list <linux-kernel@vger.kernel.org>,
        "moderated list:ARM/FREESCALE IMX / MXC ARM ARCHITECTURE" 
        <linux-arm-kernel@lists.infradead.org>, landy.gross@linaro.org,
        David Brown <david.brown@linaro.org>,
        linux-arm-msm@vger.kernel.org, linux-soc@vger.kernel.org,
        indranilghsh428@gmail.com
Subject: Re: [BUG]: Kernel 4.9: Kernel crash at fs/sysfs/file.c :
 sysfs_kf_seq_show
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References: <CAOuPNLiUBhJdsgw9bjQxxhkeBHQFoE_vN_Na6kw3ksr89r+HOg@mail.gmail.com>
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On Tue, Jan 12, 2021 at 05:31:54PM +0530, Pintu Agarwal wrote:
> Hi,
> 
> I am using Kernel: 4.9.217 for one of the ARM32 boards for Qualcomm SOC.
> https://github.com/android-linux-stable/msm-4.9
> 
> But I think this is a general bug applicable to :Kernel 4.9 under
> fs/sysfs/file.c
> So, I wanted to quickly check here if others are familiar with this
> issue and if it is fixed already.
> Note, this issue does not occur in 4.14 Kernel.
> 
> When I execute below command, the Kernel is crashing.
> I tried to add few debug prints to find more details. I see that the
> ops->show pointer is not valid (seems corrupted).
> So I wanted to understand how this can happen only for this particular node.
> Other sysfs entries are working fine.
> 
> # cat /sys/power/rpmh_stats/master_stats

Also note that this file is not in the upstream kernel tree, so there's
not much we can do about this either...

good luck!

greg k-h