[BUG]: Kernel 4.9: Kernel crash at fs/sysfs/file.c : sysfs_kf_seq_show

[Pintu Agarwal]

On Tue, 12 Jan 2021 at 17:39, Greg Kroah-Hartman
<gregkh at linuxfoundation.org> wrote:
>
> 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.
> >

I see that this issue was reported earlier as well by others.
https://syzkaller.appspot.com/bug?id=2ec2a9da5c711df3d3d12071bac487b96e75e103
https://gitlab.freedesktop.org/drm/amd/-/issues/413
https://bugzilla.redhat.com/show_bug.cgi?id=1615070

So it seems to be common issue and thus I wanted to check here if its similar.

Thanks,
Pintu