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From:   Xiaomeng Tong <xiam0nd.tong@gmail.com>
To:     snitzer@redhat.com
Cc:     agk@redhat.com, dm-devel@redhat.com, linux-kernel@vger.kernel.org,
        stable@vger.kernel.org, xiam0nd.tong@gmail.com
Subject: Re: md: fix missing check on list iterator
Date:   Sun,  3 Apr 2022 11:56:03 +0800
Message-Id: <20220403035603.16169-1-xiam0nd.tong@gmail.com>
In-Reply-To: <YkcQdjE6uTfScyEy@redhat.com>
References: <YkcQdjE6uTfScyEy@redhat.com>
Precedence: bulk

On Fri, 1 Apr 2022 10:47:18 -0400, Mike Snitzer wrote:
> Did you acually hit a bug (invalid memory access)?
> 
> I cannot see how given the checks prior to iterating m->priority_groups:
> 
>         if (!pgstr || (sscanf(pgstr, "%u%c", &pgnum, &dummy) != 1) || !pgnum ||
>             !m->nr_priority_groups || (pgnum > m->nr_priority_groups)) {
>                 DMWARN("invalid PG number supplied to bypass_pg");
>                 return -EINVAL;
>         }
> 
> So I have _not_ taken your "fix".

Yes, you are correct. It has been checked before, thus not a bug and
no need to fix. And I have sent a PATCH v2 to use list iterator only
inside the loop, please check it. Thank you very much.

--
Xiaomeng Tong