From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 43A21C25B0E for ; Tue, 16 Aug 2022 18:48:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236044AbiHPSsS (ORCPT ); Tue, 16 Aug 2022 14:48:18 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36804 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232654AbiHPSsR (ORCPT ); Tue, 16 Aug 2022 14:48:17 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 41DD66338 for ; Tue, 16 Aug 2022 11:48:16 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id EE9FCB81AA9 for ; Tue, 16 Aug 2022 18:48:14 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 61B40C433D6; Tue, 16 Aug 2022 18:48:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1660675693; bh=f5wBYm2DYlyFdHcAIFTSXbusboTGLq7mBcEZ+py7tfE=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=KRXoEXfFxf+Ywy0eVjPbrEw7VHwe8qGkNS8bLgBmaEvjRclvW2Kxyg6kgXDaDJJH2 H5bcKp3qXFhRneq74Gby3/RUXUA6MpcTm0gmLEnkDDjmPYI+TdpuAW+vrNmbobI4Tm j2LahDbx7vcxroa6iDQEo5p47OxHKDkXOLj5WsZiZqacvlG2zm5SsvaovdLWIJ+kfa YoVk5oi7gWN5+c9+DaASJAFfWJhXUUHuqEORsrT8MZuaje9/MFTwv2ZWVOEr1BfIqW GHIA1egA2Cs+KP6nuBF+6e/zMJVwvEj8kOsvb8YZR2hxPEV70DDu9rrf+wKOnNgSmQ o9IGRfhtGCy9w== Date: Tue, 16 Aug 2022 11:48:11 -0700 From: Eric Biggers To: cgel.zte@gmail.com Cc: davem@davemloft.net, herbert@gondor.apana.org.au, linux-crypto@vger.kernel.org, ye xingchen , Zeal Robot Subject: Re: [PATCH linux-next] crypto: api - Avoid NULL pointer dereference in crypto_larval_destroy() Message-ID: References: <20220816113722.82894-1-ye.xingchen@zte.com.cn> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20220816113722.82894-1-ye.xingchen@zte.com.cn> Precedence: bulk List-ID: X-Mailing-List: linux-crypto@vger.kernel.org On Tue, Aug 16, 2022 at 11:37:22AM +0000, cgel.zte@gmail.com wrote: > From: ye xingchen > > When we have no primary larval or when it's a software node, we may end up > in the situation when larval is a NULL pointer. There is no point to look > for secondary larval in such case. Add a necessary check to a condition. > > Reported-by: Zeal Robot > Signed-off-by: ye xingchen > --- > crypto/api.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/crypto/api.c b/crypto/api.c > index 69508ae9345e..f2399aac831d 100644 > --- a/crypto/api.c > +++ b/crypto/api.c > @@ -96,7 +96,7 @@ static void crypto_larval_destroy(struct crypto_alg *alg) > struct crypto_larval *larval = (void *)alg; > > BUG_ON(!crypto_is_larval(alg)); > - if (!IS_ERR_OR_NULL(larval->adult)) > + if (larval && !IS_ERR_OR_NULL(larval->adult)) > crypto_mod_put(larval->adult); > kfree(larval); > } > -- How does this new NULL check do anything when the pointer is unconditionally dereferenced in the previous line? - Eric