linux-kernel - Re: drm_vm.c:drm_mmap: possible circular locking dependency detected

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

Date:	Tue, 05 Jan 2010 08:09:59 +0900
From:	Tejun Heo <tj@...nel.org>
To:	"Eric W. Biederman" <ebiederm@...ssion.com>
CC:	Dmitry Torokhov <dmitry.torokhov@...il.com>,
	Linus Torvalds <torvalds@...ux-foundation.org>,
	KOSAKI Motohiro <kosaki.motohiro@...fujitsu.com>,
	Borislav Petkov <petkovbb@...glemail.com>,
	David Airlie <airlied@...ux.ie>,
	Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
	Greg KH <greg@...ah.com>, Al Viro <viro@...IV.linux.org.uk>
Subject: Re: drm_vm.c:drm_mmap: possible circular locking dependency detected

Hello,

On 01/05/2010 04:43 AM, Eric W. Biederman wrote:
>>> So it is unlikely but possible to deadlock by accessing a serio
>>> attribute of a serio device that is being removed.
>>
>> Hmm, I guess I was too quick dismissing lockdep complaints here. Now
>> that sysfs remove waits deadlock indeed is possible. Actually the locks
>> on serio->drv_mutex in attributes were added to make sure we don't
>> access device that was unbound from the driver through stale sysfs
>> attributes.
> 
> Cool.  So we have solved the problem generically but we have left over
> layer specific solutions.  That seems like a good problem to have.

This is way too cool.  Only if we can have more moments like this.  :-)

-- 
tejun
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/