From: PrasannaKumar Muralidharan Subject: Re: [PATCH] Fix NULL pointer deref. on no default_rng Date: Sun, 12 Nov 2017 20:16:27 +0530 Message-ID: References: <20171112142432.20186-1-pinaraf@pinaraf.info> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Cc: "open list:HARDWARE RANDOM NUMBER GENERATOR CORE" , "David S . Miller" , Herbert Xu To: Pierre Ducroquet Return-path: Received: from mail-io0-f193.google.com ([209.85.223.193]:51355 "EHLO mail-io0-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750953AbdKLOq2 (ORCPT ); Sun, 12 Nov 2017 09:46:28 -0500 Received: by mail-io0-f193.google.com with SMTP id g73so2458206ioj.8 for ; Sun, 12 Nov 2017 06:46:28 -0800 (PST) In-Reply-To: <20171112142432.20186-1-pinaraf@pinaraf.info> Sender: linux-crypto-owner@vger.kernel.org List-ID: Hi Pierre, On 12 November 2017 at 19:54, Pierre Ducroquet wrote: > If crypto_get_default_rng returns an error, the > function ecc_gen_privkey should return an error. > Instead, it currently tries to use the default_rng > nevertheless, thus creating a kernel panic with a > NULL pointer dereference. > Returning the error directly, as was supposedly > intended when looking at the code, fixes this. > > Signed-off-by: Pierre Ducroquet > --- > crypto/ecc.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/crypto/ecc.c b/crypto/ecc.c > index 633a9bcdc574..18f32f2a5e1c 100644 > --- a/crypto/ecc.c > +++ b/crypto/ecc.c > @@ -964,7 +964,7 @@ int ecc_gen_privkey(unsigned int curve_id, unsigned int ndigits, u64 *privkey) > * DRBG with a security strength of 256. > */ > if (crypto_get_default_rng()) > - err = -EFAULT; > + return -EFAULT; > > err = crypto_rng_get_bytes(crypto_default_rng, (u8 *)priv, nbytes); > crypto_put_default_rng(); > -- > 2.15.0 > Looks good to me. Reviewed-by: PrasannaKumar Muralidharan Regards, PrasannaKumar