From linux-kernel  Fri Aug 13 17:38:34 2021
From: Keith Packard <keithp () keithp ! com>
Date: Fri, 13 Aug 2021 17:38:34 +0000
To: linux-kernel
Subject: Re: [PATCH] usb: misc: chaoskey: remove useless else
Message-Id: <87bl61utwl.fsf () keithp ! com>
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Salah Triki <salah.triki@gmail.com> writes:

> Remove useless else in order to make the code cleaner.

> -	if (!dev->present) {
> -		if (dev->open =3D=3D 0) {
> -			mutex_unlock(&dev->lock);
> +	mutex_unlock(&dev->lock);
> +
> +	if (!dev->present)
> +		if (dev->open =3D=3D 0)
>  			chaoskey_free(dev);
> -		} else
> -			mutex_unlock(&dev->lock);
> -	} else
> -		mutex_unlock(&dev->lock);

This accesses dev->present outside of the lock region introducing a
potential race condition.

=2D-=20
=2Dkeith

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