linux-kernel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: "Xu, Yanfei" <yanfei.xu@windriver.com>
To: Dongliang Mu <mudongliangabcd@gmail.com>,
	"Russell King (Oracle)" <linux@armlinux.org.uk>
Cc: Dan Carpenter <dan.carpenter@oracle.com>,
	Pavel Skripkin <paskripkin@gmail.com>,
	Bartosz Golaszewski <bgolaszewski@baylibre.com>,
	andrew@lunn.ch, hkallweit1@gmail.com,
	"David S. Miller" <davem@davemloft.net>,
	Jakub Kicinski <kuba@kernel.org>,
	p.zabel@pengutronix.de,
	syzbot <syzbot+398e7dc692ddbbb4cfec@syzkaller.appspotmail.com>,
	linux-kernel <linux-kernel@vger.kernel.org>,
	"open list:NETWORKING [GENERAL]" <netdev@vger.kernel.org>
Subject: Re: [PATCH] net: mdiobus: Fix memory leak in __mdiobus_register
Date: Wed, 29 Sep 2021 10:05:42 +0800	[thread overview]
Message-ID: <bc07380e-54ae-1699-aaaf-3380f11c3eaf@windriver.com> (raw)
In-Reply-To: <CAD-N9QXHcrv+6SJSOz3NyBkAnze2wVf_azYmjbGCVd5Ge_OQng@mail.gmail.com>



On 9/28/21 11:48 PM, Dongliang Mu wrote:
> [Please note: This e-mail is from an EXTERNAL e-mail address]
> 
> On Tue, Sep 28, 2021 at 11:41 PM Russell King (Oracle)
> <linux@armlinux.org.uk> wrote:
>>
>> On Tue, Sep 28, 2021 at 04:52:07PM +0300, Dan Carpenter wrote:
>>> On Tue, Sep 28, 2021 at 01:58:00PM +0100, Russell King (Oracle) wrote:
>>>>
>>>> This thread seems to be getting out of hand.
>>>
>>> The thread was closed.  We need to revert Yanfei's patch and apply
>>> Pavel's patch.  He's going to resend.
>>>

Sorry for my patch, it is my bad. :( And thanks for Pavel's v2 which 
help to revert mine.

Regards,
Yanfei

>>>> So, I would suggest a simple fix is to set bus->state to
>>>> MDIOBUS_UNREGISTERED immediately _after_ the successful
>>>> device_register().
>>>
>>> Not after.  It has to be set to MDIOBUS_UNREGISTERED if device_register()
>>> fails, otherwise there will still be a leak.
>>
>> Ah yes, you are correct - the device name may not be freed. Also...
>>
>>   * NOTE: _Never_ directly free @dev after calling this function, even
>>   * if it returned an error! Always use put_device() to give up your
>>   * reference instead.
>>
>> So yes, we must set to MDIOBUS_UNREGISTERED even if device_register()
>> fails.
>>
> 
> So we have reached an agreement. Pavel's patch fixes the syzbot link
> [1], other than Yanfei's patch. However, Yanfei's patch also fixes
> another memory link nearby.
> 
> Right?
> 
> [1] https://syzkaller.appspot.com/bug?id=fa99459691911a0369622248e0f4e3285fcedd97
> 
>> --
>> RMK's Patch system: https://www.armlinux.org.uk/developer/patches/
>> FTTP is here! 40Mbps down 10Mbps up. Decent connectivity at last!

  reply	other threads:[~2021-09-29  2:06 UTC|newest]

Thread overview: 23+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-09-26  4:53 [PATCH] net: mdiobus: Fix memory leak in __mdiobus_register Yanfei Xu
2021-09-26 15:34 ` Andrew Lunn
2021-09-27 12:30 ` patchwork-bot+netdevbpf
2021-09-28  8:55 ` Dan Carpenter
2021-09-28  9:26   ` Dan Carpenter
2021-09-28  9:45     ` Pavel Skripkin
2021-09-28 10:39       ` Dan Carpenter
2021-09-28 10:46         ` Pavel Skripkin
2021-09-28 10:55           ` Dan Carpenter
2021-09-28 11:04             ` Pavel Skripkin
2021-09-28 10:59           ` Dan Carpenter
2021-09-28 11:06             ` Pavel Skripkin
2021-09-28 11:09               ` Pavel Skripkin
2021-09-28 11:30                 ` Dan Carpenter
2021-09-28 11:45                   ` Pavel Skripkin
2021-09-28 12:23                     ` Dan Carpenter
2021-09-28 12:58                   ` Russell King (Oracle)
2021-09-28 13:52                     ` Dan Carpenter
2021-09-28 15:41                       ` Russell King (Oracle)
2021-09-28 15:48                         ` Dongliang Mu
2021-09-29  2:05                           ` Xu, Yanfei [this message]
2021-09-28 13:11 ` Russell King (Oracle)
2021-09-29 21:31 ` Denis Efremov

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=bc07380e-54ae-1699-aaaf-3380f11c3eaf@windriver.com \
    --to=yanfei.xu@windriver.com \
    --cc=andrew@lunn.ch \
    --cc=bgolaszewski@baylibre.com \
    --cc=dan.carpenter@oracle.com \
    --cc=davem@davemloft.net \
    --cc=hkallweit1@gmail.com \
    --cc=kuba@kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux@armlinux.org.uk \
    --cc=mudongliangabcd@gmail.com \
    --cc=netdev@vger.kernel.org \
    --cc=p.zabel@pengutronix.de \
    --cc=paskripkin@gmail.com \
    --cc=syzbot+398e7dc692ddbbb4cfec@syzkaller.appspotmail.com \
    /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 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).