linux-kernel - Re: [PATCH] binder: Don't use mmput() from shrinker function.

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]

Message-ID: <20200716135445.GN31089@dhcp22.suse.cz>
Date:   Thu, 16 Jul 2020 15:54:45 +0200
From:   Michal Hocko <mhocko@...nel.org>
To:     Tetsuo Handa <penguin-kernel@...ove.sakura.ne.jp>
Cc:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        Arve Hjonnevag <arve@...roid.com>,
        Todd Kjos <tkjos@...roid.com>,
        Martijn Coenen <maco@...roid.com>,
        Joel Fernandes <joel@...lfernandes.org>,
        Christian Brauner <christian@...uner.io>,
        syzbot <syzbot+e5344baa319c9a96edec@...kaller.appspotmail.com>,
        acme@...nel.org, alexander.shishkin@...ux.intel.com,
        jolsa@...hat.com, linux-kernel@...r.kernel.org,
        mark.rutland@....com, mingo@...hat.com, namhyung@...nel.org,
        peterz@...radead.org, syzkaller-bugs@...glegroups.com,
        "open list:ANDROID DRIVERS" <devel@...verdev.osuosl.org>,
        linux-mm <linux-mm@...ck.org>
Subject: Re: [PATCH] binder: Don't use mmput() from shrinker function.

On Thu 16-07-20 22:41:14, Tetsuo Handa wrote:
> On 2020/07/16 17:35, Michal Hocko wrote:
[...]
> > But in order for this to happen the shrinker would have to do the last
> > put on the mm. But mm cannot go away from under uprobe_mmap so those two
> > paths cannot race with each other.
> 
> and mm1 != mm2 is possible, isn't it?

OK, I have missed that information. You are right. Can you make this
into the changelog please?
-- 
Michal Hocko
SUSE Labs