All of lore.kernel.org
 help / color / mirror / Atom feed
From: Hans de Goede <hdegoede@redhat.com>
To: Andy Shevchenko <andy.shevchenko@gmail.com>
Cc: Mark Gross <mgross@linux.intel.com>,
	Andy Shevchenko <andy@infradead.org>,
	Mark Pearson <markpearson@lenovo.com>,
	Platform Driver <platform-driver-x86@vger.kernel.org>
Subject: Re: [PATCH] platform/x86: think-lmi: Return EINVAL when kbdlang gets set to a 0 length string
Date: Mon, 21 Jun 2021 16:13:34 +0200	[thread overview]
Message-ID: <ca520d5f-0288-30ef-0191-96f890a2ba4c@redhat.com> (raw)
In-Reply-To: <CAHp75Veh-t0KO4To8gbZej1bifJbrc3ppxnLzun0BcbsOBqZnA@mail.gmail.com>

Hi,

On 6/21/21 3:58 PM, Andy Shevchenko wrote:
> On Mon, Jun 21, 2021 at 4:24 PM Hans de Goede <hdegoede@redhat.com> wrote:
>>
>> Commit 0ddcf3a6b442 ("platform/x86: think-lmi: Avoid potential read before
>> start of the buffer") moved the lengt == 0 up to before stripping the '\n'
> 
> length

Ack, will fix.

>> which typically gets added when users echo a value to a sysfs-attribute
>> from the shell.
>>
>> This avoids a potential buffer-underrun, but it also causes a behavioral
>> change, prior to this change "echo > kbdlang", iow writing just a single
>> '\n' would result in an EINVAL error, but after the change this gets
>> accepted setting kbdlang to an empty string.
> 
> And why is it a problem?

Because there are only a couple of valid string like "de", "fr", "es"
and "us". We don't know the exact set of valid strings for a certain
BIOS, but we do not for sure that an empty string is not valid.

Regards,

Hans


  reply	other threads:[~2021-06-21 14:13 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-06-21 13:23 [PATCH] platform/x86: think-lmi: Return EINVAL when kbdlang gets set to a 0 length string Hans de Goede
2021-06-21 13:58 ` Andy Shevchenko
2021-06-21 14:13   ` Hans de Goede [this message]
2021-06-21 16:16     ` Andy Shevchenko
2021-06-21 19:29       ` Hans de Goede

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=ca520d5f-0288-30ef-0191-96f890a2ba4c@redhat.com \
    --to=hdegoede@redhat.com \
    --cc=andy.shevchenko@gmail.com \
    --cc=andy@infradead.org \
    --cc=markpearson@lenovo.com \
    --cc=mgross@linux.intel.com \
    --cc=platform-driver-x86@vger.kernel.org \
    /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
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.