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Date:   Fri, 08 Nov 2019 14:12:24 -0800 (PST)
Message-Id: <20191108.141224.1561483712458439557.davem@davemloft.net>
To:     jiri@resnulli.us
Cc:     netdev@vger.kernel.org, jakub.kicinski@netronome.com,
        idosch@mellanox.com, mlxsw@mellanox.com
Subject: Re: [patch net-next] devlink: disallow reload operation during
 device cleanup
From:   David Miller <davem@davemloft.net>
In-Reply-To: <20191108204243.7241-1-jiri@resnulli.us>
References: <20191108204243.7241-1-jiri@resnulli.us>
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From: Jiri Pirko <jiri@resnulli.us>
Date: Fri,  8 Nov 2019 21:42:43 +0100

> From: Jiri Pirko <jiri@mellanox.com>
> 
> There is a race between driver code that does setup/cleanup of device
> and devlink reload operation that in some drivers works with the same
> code. Use after free could we easily obtained by running:
> 
> while true; do
>         echo 10 > /sys/bus/netdevsim/new_device
>         devlink dev reload netdevsim/netdevsim10 &
>         echo 10 > /sys/bus/netdevsim/del_device
> done
> 
> Fix this by enabling reload only after setup of device is complete and
> disabling it at the beginning of the cleanup process.
> 
> Reported-by: Ido Schimmel <idosch@mellanox.com>
> Fixes: 2d8dc5bbf4e7 ("devlink: Add support for reload")
> Signed-off-by: Jiri Pirko <jiri@mellanox.com>

Applied.