netdev - RE: [Question] Usage of dev_hold()/dev

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Message-ID: <60A73B7A161A82449A7DB7B382BFD15537141CC2@SZXEMA504-MBS.china.huawei.com>
Date:	Thu, 27 Aug 2015 01:05:07 +0000
From:	"Zhangjie (HZ)" <zhangjie14@...wei.com>
To:	Eric Dumazet <eric.dumazet@...il.com>
CC:	Jason Wang <jasowang@...hat.com>,
	"netdev@...r.kernel.org" <netdev@...r.kernel.org>,
	Qinchuanyu <qinchuanyu@...wei.com>, Yewudi <yewudi@...wei.com>,
	liuyongan 00175866 <l00175866@...esmail.huawei.com.cn>,
	Wangbicheng <wangbicheng@...wei.com>,
	Yan Chen <Y.Chen@...wei.com>
Subject: RE: [Question] Usage of dev_hold()/dev_put()

Very clear explanation，thank you! :-)

Zhangjie

-----Original Message-----
From: Eric Dumazet [mailto:eric.dumazet@...il.com] 
Sent: Wednesday, August 26, 2015 9:10 PM
To: Zhangjie (HZ)
Cc: Jason Wang; netdev@...r.kernel.org; Qinchuanyu; Yewudi; liuyongan 00175866; Wangbicheng; Yan Chen
Subject: Re: [Question] Usage of dev_hold()/dev_put()

On Wed, 2015-08-26 at 07:48 +0000, Zhangjie (HZ) wrote:
> Eric,
> Thank you for your patient apply.
> There is still a question, 
> In receive path, driver does not call dev_hold(), when skb goes to host stack, skb->dev is likely to be used. 
> If device is destroyed before that, it seems dangerous.

This is also handled properly.

Check : flush_backlog() in net/core/dev.c
   sock_queue_rcv_skb() , and all functions setting skb->dev to NULL