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Subject: Re: [PATCH 2/2] block: fix ioprio_get/set(IOPRIO_WHO_PGRP) vs
 setuid(2)
To:     Davidlohr Bueso <dave@stgolabs.net>, akpm@linux-foundation.org
Cc:     oleg@redhat.com, linux-kernel@vger.kernel.org,
        Greg Thelen <gthelen@google.com>,
        Davidlohr Bueso <dbueso@suse.de>
References: <20200817003148.23691-1-dave@stgolabs.net>
 <20200817003148.23691-3-dave@stgolabs.net>
From:   Jens Axboe <axboe@kernel.dk>
Message-ID: <2741d70f-31a9-3f8f-d74d-ce3de4c1bd3d@kernel.dk>
Date:   Mon, 17 Aug 2020 07:12:26 -0700
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On 8/16/20 5:31 PM, Davidlohr Bueso wrote:
> do_each_pid_thread(PIDTYPE_PGID) can race with a concurrent
> change_pid(PIDTYPE_PGID) that can move the task from one hlist
> to another while iterating. Serialize ioprio_get/set to take
> the tasklist_lock in this case.

LGTM:

Reviewed-by: Jens Axboe <axboe@kernel.dk>

-- 
Jens Axboe