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

[Greg Kroah-Hartman]

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