linux-kernel - Re: [PATCH block/for-linus] block: blkg_destroy_all() should clear q->root_blkg and ->root

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: <55EF0028.30203@kernel.dk>
Date:	Tue, 8 Sep 2015 09:35:04 -0600
From:	Jens Axboe <axboe@...nel.dk>
To:	Tejun Heo <tj@...nel.org>
Cc:	Josh Boyer <jwboyer@...oraproject.org>,
	Jeff Moyer <jmoyer@...hat.com>, msnitzer@...hat.com,
	Li Zefan <lizefan@...wei.com>,
	Johannes Weiner <hannes@...xchg.org>, cgroups@...r.kernel.org,
	"Linux-Kernel@...r. Kernel. Org" <linux-kernel@...r.kernel.org>,
	"Richard W.M. Jones" <rjones@...hat.com>
Subject: Re: [PATCH block/for-linus] block: blkg_destroy_all() should clear
 q->root_blkg and ->root_rl.blkg

On 09/08/2015 09:31 AM, Tejun Heo wrote:
> On Sat, Sep 05, 2015 at 03:47:36PM -0400, Tejun Heo wrote:
>> While making the root blkg unconditional, ec13b1d6f0a0 ("blkcg: always
>> create the blkcg_gq for the root blkcg") removed the part which clears
>> q->root_blkg and ->root_rl.blkg during q exit.  This leaves the two
>> pointers dangling after blkg_destroy_all().  blk-throttle exit path
>> performs blkg traversals and dereferences ->root_blkg and can lead to
>> the following oops.
>
> Jens, can you please route this one w/ Richard's tested-by added?

Yup, added, thanks.

-- 
Jens Axboe

--
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/