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Date:   Mon, 26 Oct 2020 15:01:45 +0800
From:   Can Guo <cang@codeaurora.org>
To:     Avri Altman <Avri.Altman@wdc.com>
Cc:     asutoshd@codeaurora.org, nguyenb@codeaurora.org,
        hongwus@codeaurora.org, rnayak@codeaurora.org,
        linux-scsi@vger.kernel.org, kernel-team@android.com,
        saravanak@google.com, salyzyn@google.com,
        Alim Akhtar <alim.akhtar@samsung.com>,
        "James E.J. Bottomley" <jejb@linux.ibm.com>,
        "Martin K. Petersen" <martin.petersen@oracle.com>,
        Stanley Chu <stanley.chu@mediatek.com>,
        Bean Huo <beanhuo@micron.com>,
        Bart Van Assche <bvanassche@acm.org>,
        open list <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH v2 1/1] scsi: ufs: Fix unexpected values get from
 ufshcd_read_desc_param()
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On 2020-10-26 13:22, Avri Altman wrote:
>> On 2020-10-22 14:37, Avri Altman wrote:
>> >> Since WB feature has been added, WB related sysfs entries can be
>> >> accessed
>> >> even when an UFS device does not support WB feature. In that case, the
>> >> descriptors which are not supported by the UFS device may be wrongly
>> >> reported when they are accessed from their corrsponding sysfs entries.
>> >> Fix it by adding a sanity check of parameter offset against the actual
>> >> decriptor length.s
>> > This should be a bug fix IMO, and be dealt with similarly like
>> > ufshcd_is_wb_attrs or ufshcd_is_wb_flag.
>> > Thanks,
>> > Avri
>> 
>> Could you please elaborate on ufshcd_is_wb_attrs or ufshcd_is_wb_flag?
>> Sorry that I don't quite get it.
> Since this change is only protecting illegal access from sysfs entries,
> I am suggesting to handle it there, just like ufshcd_is_wb_attrs or
> ufshcd_is_wb_flag
> Are doing it for flags and attributes.
> 
> Thanks,
> Avri

This is a general problem - if later we have HPB entries added into 
sysfs,
we will hit it again. We cannot keep adding checks like 
ufshcd_is_xxx_attrs
or ufshcd_is_xxx_flag to block them, right?

Thanks,

Can Guo.