Re: [PATCH] loop: fix to a race condition due to the early registration of device

From: Omar Sandoval
Date: Tue Aug 08 2017 - 18:00:56 EST


On Mon, Aug 07, 2017 at 03:37:50PM +0300, Anton Volkov wrote:
> The early device registration made possible a race leading to allocations
> of disks with wrong minors.
>
> This patch moves the device registration further down the loop_init
> function to make the race infeasible.
>
> Found by Linux Driver Verification project (linuxtesting.org).
>
> Signed-off-by: Anton Volkov <avolkov@xxxxxxxxx>
> Reviewed-by: Ming Lei <ming.lei@xxxxxxxxxx>

Hi, Anton,

Were you able to reproduce this issue or was it purely theoretical? If
the former, it'd be nice if you could add a test case to blktests [1].

1: https://github.com/osandov/blktests

Thanks!
Omar