Linux-Fsdevel Archive on lore.kernel.org
help / color / mirror / Atom feed
From: Tetsuhiro Kohada <kohada.t2@gmail.com>
To: Namjae Jeon <namjae.jeon@samsung.com>
Cc: kohada.tetsuhiro@dc.mitsubishielectric.co.jp,
	mori.takahiro@ab.mitsubishielectric.co.jp,
	motai.hirotaka@aj.mitsubishielectric.co.jp,
	'Sungjong Seo' <sj1557.seo@samsung.com>,
	linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v3] exfat: integrates dir-entry getting and validation
Date: Wed, 26 Aug 2020 11:56:22 +0900	[thread overview]
Message-ID: <d1df9cca-3020-9e1e-0f3d-9db6752a22b6@gmail.com> (raw)
In-Reply-To: <000101d67b44$ac458c80$04d0a580$@samsung.com>

On 2020/08/26 10:03, Namjae Jeon wrote:
>> Second: Range validation and type validation should not be separated.
>> When I started making this patch, I intended to add only range validation.
>> However, after the caller gets the ep, the type validation follows.
>> Get ep, null check of ep (= range verification), type verification is a series of procedures.
>> There would be no reason to keep them independent anymore.
>> Range and type validation is enforced when the caller uses ep.
> You can add a validate flags as argument of exfat_get_dentry_set(), e.g. none, basic and strict.
> none : only range validation.
> basic : range + type validation.
> strict : range + type + checksum and name length, etc.

Currently, various types of verification will not be needed.
Let's add it when we need it.
>   
>>> -	/* validiate cached dentries */
>>> -	for (i = 1; i < num_entries; i++) {
>>> -		ep = exfat_get_dentry_cached(es, i);
>>> -		if (!exfat_validate_entry(exfat_get_entry_type(ep), &mode))
>>> +	ep = exfat_get_dentry_cached(es, ENTRY_STREAM);
>>> +	if (!ep || ep->type != EXFAT_STREAM)
>>> +		goto free_es;
>>> +	es->de[ENTRY_STREAM] = ep;
>>
>> The value contained in stream-ext dir-entry should not be used before validating the EntrySet checksum.
>> So I would insert EntrySet checksum validation here.
>> In that case, the checksum verification loop would be followed by the TYPE_NAME verification loop, can
>> you acceptable?
> Yes. That would be great.

OK.
I'll add TYPE_NAME verification after checksum verification, in next patch.
However, I think it is enough to validate TYPE_NAME when extracting name.
Could you please tell me why you think you need TYPE_NAME validation here?


BR
---
Tetsuhiro Kohada <kohada.t2@gmail.com>
> 

  reply	other threads:[~2020-08-26  2:56 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <CGME20200806010249epcas1p18fd6e3febad305975b43e1b55b56bcae@epcas1p1.samsung.com>
2020-08-06  1:02 ` Tetsuhiro Kohada
2020-08-08 16:35   ` Sungjong Seo
2020-08-10  6:10   ` Namjae Jeon
2020-08-12 13:25     ` Tetsuhiro Kohada
2020-08-21  6:53       ` Namjae Jeon
2020-08-25  8:21         ` Tetsuhiro Kohada
2020-08-26  1:03           ` Namjae Jeon
2020-08-26  2:56             ` Tetsuhiro Kohada [this message]
2020-08-26  4:19               ` Namjae Jeon
2020-08-26  6:07                 ` Tetsuhiro Kohada
2020-08-26  7:32                   ` Namjae Jeon
2020-08-27  9:59                     ` Tetsuhiro Kohada

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=d1df9cca-3020-9e1e-0f3d-9db6752a22b6@gmail.com \
    --to=kohada.t2@gmail.com \
    --cc=kohada.tetsuhiro@dc.mitsubishielectric.co.jp \
    --cc=linux-fsdevel@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=mori.takahiro@ab.mitsubishielectric.co.jp \
    --cc=motai.hirotaka@aj.mitsubishielectric.co.jp \
    --cc=namjae.jeon@samsung.com \
    --cc=sj1557.seo@samsung.com \
    --subject='Re: [PATCH v3] exfat: integrates dir-entry getting and validation' \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).