Re: [PATCH] crypto: cavium/nitrox - Fix 'nitrox_get_first_device()' when ndevlist is fully iterated

[Herbert Xu]

On Tue, May 19, 2020 at 10:45:03PM +0200, Christophe JAILLET wrote:
> When a list is completely iterated with 'list_for_each_entry(x, ...)', x is
> not NULL at the end.
> 
> Introduce an intermediate variable and test it instead, in order to
> reliably know if something was found or not.
> 
> Fixes: f2663872f073 ("crypto: cavium - Register the CNN55XX supported crypto algorithms.")
> Signed-off-by: Christophe JAILLET <christophe.jaillet@xxxxxxxxxx>
> ---
>  drivers/crypto/cavium/nitrox/nitrox_main.c | 9 ++++++---
>  1 file changed, 6 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/crypto/cavium/nitrox/nitrox_main.c b/drivers/crypto/cavium/nitrox/nitrox_main.c
> index 788c6607078b..172cafe7c039 100644
> --- a/drivers/crypto/cavium/nitrox/nitrox_main.c
> +++ b/drivers/crypto/cavium/nitrox/nitrox_main.c
> @@ -278,15 +278,18 @@ static void nitrox_remove_from_devlist(struct nitrox_device *ndev)
>  
>  struct nitrox_device *nitrox_get_first_device(void)
>  {
> -	struct nitrox_device *ndev = NULL;
> +	struct nitrox_device *ndev;
> +	bool found = false;
>  
>  	mutex_lock(&devlist_lock);
>  	list_for_each_entry(ndev, &ndevlist, list) {
> -		if (nitrox_ready(ndev))
> +		if (nitrox_ready(ndev)) {
> +			found = true;
>  			break;
> +		}
>  	}
>  	mutex_unlock(&devlist_lock);
> -	if (!ndev)

Instead of adding found, you could fix this by changing the test to

	if (&ndev->list == &nevlist)

Cheers,
-- 
Email: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt