lkml.org 
[lkml]   [2020]   [Aug]   [25]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectRe: [PATCH v3] exfat: integrates dir-entry getting and validation
From
Date
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>
>

\
 
 \ /
  Last update: 2020-08-26 04:57    [W:0.090 / U:0.508 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site