Date:   Sun, 12 Mar 2023 12:10:38 +0100
From:   Greg KH <gregkh@linuxfoundation.org>
To:     Herbert Xu <herbert@gondor.apana.org.au>
Cc:     Toke =?iso-8859-1?Q?H=F8iland-J=F8rgensen?= <toke@redhat.com>,
        "David S. Miller" <davem@davemloft.net>,
        Horia =?utf-8?Q?Geant=C4=83?= <horia.geanta@nxp.com>,
        Pankaj Gupta <pankaj.gupta@nxp.com>,
        Gaurav Jain <gaurav.jain@nxp.com>,
        Mathew McBride <matt@traverse.com.au>, stable@vger.kernel.org,
        linux-crypto@vger.kernel.org
Subject: Re: [PATCH] crypto: Demote BUG_ON() in crypto_unregister_alg() to a
 WARN_ON()
Message-ID: <ZA2zLtqrI4aeLSTj@kroah.com>
References: <20230311162513.6746-1-toke@redhat.com>
 <ZA1+zr0NapJlsKk9@gondor.apana.org.au>
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On Sun, Mar 12, 2023 at 03:27:10PM +0800, Herbert Xu wrote:
> On Sat, Mar 11, 2023 at 05:25:12PM +0100, Toke H?iland-J?rgensen wrote:
> >
> > diff --git a/crypto/algapi.c b/crypto/algapi.c
> > index d08f864f08be..e9954fcb61be 100644
> > --- a/crypto/algapi.c
> > +++ b/crypto/algapi.c
> > @@ -493,7 +493,7 @@ void crypto_unregister_alg(struct crypto_alg *alg)
> >  	if (WARN(ret, "Algorithm %s is not registered", alg->cra_driver_name))
> >  		return;
> >  
> > -	BUG_ON(refcount_read(&alg->cra_refcnt) != 1);
> > +	WARN_ON(refcount_read(&alg->cra_refcnt) != 1);
> 
> I think we should return here instead of continuing to destroy
> the algorithm since we know that it's still in use.

Also, this still panics a box with panic-on-warn enabled, so if this can
be handled, returning an error is good.

thanks,

greg k-h