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 for linux-mtd@lists.infradead.org; Mon, 03 Sep 2018 13:28:49 +0000
Subject: Re: [PATCH] jffs2: add additinal sanity check for
 jffs2_acl_from_medium()
To: Richard Weinberger <richard.weinberger@gmail.com>
Cc: David Woodhouse <dwmw2@infradead.org>,
 "linux-mtd @ lists . infradead . org" <linux-mtd@lists.infradead.org>
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From: cgxu519 <cgxu519@gmx.com>
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Date: Mon, 3 Sep 2018 21:28:31 +0800
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On 09/03/2018 04:45 PM, Richard Weinberger wrote:
> On Sun, Sep 2, 2018 at 5:45 PM Chengguang Xu <cgxu519@gmx.com> wrote:
>> In the case ACL_USER and ACL_GROUP we check if value has exceeded end,
>> add same check in the case ACL_OTHER as well.
> Did you hit a problem in that area or was this found by review?
>  From looking at the code I'd say it is fine as is.
> In the ACL_MASK/_OTHER case we don't look into the entry object like
> ACL_USER/_GROUP
> do, we immediately break the switch and run another round in the for loop.
> And here we do:
>                  entry = value;
>                  if (value + sizeof(struct jffs2_acl_entry_short) > end)
>                          goto fail;
>
> Which is what your additional check does. So, we'd check twice.
> What do I miss?

You are right, it is actually not needed. Sorry, please just drop the patch.