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Message-ID: <b2d0461b-a32b-50e0-640d-9e789bb5da30@alu.unizg.hr>
Date:   Wed, 29 Mar 2023 23:50:58 +0200
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Subject: Re: [BUG] [RFC] systemd-devd triggers kernel memleak apparently in
 drivers/core/dd.c: driver_register()
To:     =?UTF-8?Q?Thomas_Wei=c3=9fschuh?= <thomas@t-8ch.de>,
        Mark Pearson <mpearson-lenovo@squebb.ca>
Cc:     Hans de Goede <hdegoede@redhat.com>, Armin Wolf <W_Armin@gmx.de>,
        Greg KH <gregkh@linuxfoundation.org>,
        "Rafael J. Wysocki" <rafael@kernel.org>,
        linux-kernel@vger.kernel.org, markgross@kernel.org,
        platform-driver-x86@vger.kernel.org
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Content-Language: en-US, hr
From:   Mirsad Goran Todorovac <mirsad.todorovac@alu.unizg.hr>
In-Reply-To: <bccb52fa-e1c9-482c-a024-9a02179728b2@t-8ch.de>
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On 29. 03. 2023. 21:21, Thomas Weißschuh wrote:
> 
> Mar 29, 2023 14:00:22 Mark Pearson <mpearson-lenovo@squebb.ca>:
> 
>> Thanks Mirsad
>>
>> On Wed, Mar 29, 2023, at 2:49 PM, Mirsad Goran Todorovac wrote:
>> <snip>
>>>
>>> Here is the patch proposal according to what Mark advised (using
>>> different name for optitem):
>>>
>>> diff --git a/drivers/platform/x86/think-lmi.c
>>> b/drivers/platform/x86/think-lmi.c
>>> index c816646eb661..ab17254781c4 100644
>>> --- a/drivers/platform/x86/think-lmi.c
>>> +++ b/drivers/platform/x86/think-lmi.c
>>> @@ -929,8 +929,10 @@ static ssize_t current_value_show(struct kobject
>>> *kobj, struct kobj_attribute *a
>>>
>>>          /* validate and split from `item,value` -> `value` */
>>>          value = strpbrk(item, ",");
>>> -       if (!value || value == item || !strlen(value + 1))
>>> +       if (!value || value == item || !strlen(value + 1)) {
>>> +               kfree(item);
>>>                  return -EINVAL;
>>> +       }
>>>
>>>          ret = sysfs_emit(buf, "%s\n", value + 1);
>>>          kfree(item);
>>> @@ -1380,7 +1382,6 @@ static struct tlmi_pwd_setting
>>> *tlmi_create_auth(const char *pwd_type,
>>>
>>>   static int tlmi_analyze(void)
>>>   {
>>> -       acpi_status status;
>>>          int i, ret;
>>>
>>>          if (wmi_has_guid(LENOVO_SET_BIOS_SETTINGS_GUID) &&
>>> @@ -1417,8 +1418,8 @@ static int tlmi_analyze(void)
>>>                  char *p;
>>>
>>>                  tlmi_priv.setting[i] = NULL;
>>> -               status = tlmi_setting(i, &item, LENOVO_BIOS_SETTING_GUID);
>>> -               if (ACPI_FAILURE(status))
>>> +               ret = tlmi_setting(i, &item, LENOVO_BIOS_SETTING_GUID);
>>> +               if (ret)
>>
>> Really minor, but tweak to be this and save a line of code?
> 
> This hunk is actually from another commit and should not be needed here.
> 
> https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/commit/drivers/platform/x86/think-lmi.c?id=da62908efe80f132f691efc2ace4ca67626de86b

Thank you, Thomas,

Indeed, my mistake.

I have accepted Armin's suggestion to test if that patch closed the leak, and I
have just quoted it, never claiming authorship.

I ought to apologise if I made confusion here.

I was a bit euphoric about the leak being fixed, so forgive me for this blatant
mistake. Of course, putting it here would cause a patch collision, so it was a
stupid thing to do, and I would never do it in a formal patch submission ...

Thanks, anyway for correction.

Best regards,
Mirsad


-- 
Mirsad Goran Todorovac
Sistem inženjer
Grafički fakultet | Akademija likovnih umjetnosti
Sveučilište u Zagrebu
 
System engineer
Faculty of Graphic Arts | Academy of Fine Arts
University of Zagreb, Republic of Croatia
The European Union

"I see something approaching fast ... Will it be friends with me?"