From: Dan Carpenter Subject: Re: [PATCH 2/2] crypto: chcr - Fix error checking Date: Thu, 13 Apr 2017 19:13:42 +0300 Message-ID: <20170413161341.hln2v2ycs6efa5vh@mwanda> References: <20170413140415.6yikoizav7xaka43@mwanda> <8c1af6bd-b12f-4bf7-c44a-360ea2359e08@wanadoo.fr> Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: 8bit Cc: Christophe JAILLET , Herbert Xu , davem@davemloft.net, harsh@chelsio.com, hariprasad@chelsio.com, linux-crypto@vger.kernel.org, linux-kernel@vger.kernel.org, kernel-janitors@vger.kernel.org To: Harsh Jain Return-path: Received: from aserp1040.oracle.com ([141.146.126.69]:40660 "EHLO aserp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752935AbdDMQOF (ORCPT ); Thu, 13 Apr 2017 12:14:05 -0400 Content-Disposition: inline In-Reply-To: Sender: linux-crypto-owner@vger.kernel.org List-ID: On Thu, Apr 13, 2017 at 08:37:50PM +0530, Harsh Jain wrote: > On Thu, Apr 13, 2017 at 8:20 PM, Christophe JAILLET > wrote: > > Le 13/04/2017 ? 16:04, Dan Carpenter a ?crit : > >> > >> On Thu, Apr 13, 2017 at 02:14:30PM +0200, Christophe JAILLET wrote: > >>> > >>> If 'chcr_alloc_shash()' a few lines above fails, 'base_hash' can be an > >>> error pointer when we 'goto out'. > >>> So checking for NULL here is not enough because it is likely that > >>> 'chcr_free_shash' will crash if we pass an error pointer. > >>> > >>> Signed-off-by: Christophe JAILLET > >>> --- > >>> Another solution, amybe safer, would be to instrument 'chcr_free_shash' > >>> or > >>> 'crypto_free_shash' to accept an error pointer and return immediatelly in > >>> such a case. > >>> --- > >>> drivers/crypto/chelsio/chcr_algo.c | 2 +- > >>> 1 file changed, 1 insertion(+), 1 deletion(-) > >>> > >>> diff --git a/drivers/crypto/chelsio/chcr_algo.c > >>> b/drivers/crypto/chelsio/chcr_algo.c > >>> index f19590ac8775..41750b97f43c 100644 > >>> --- a/drivers/crypto/chelsio/chcr_algo.c > >>> +++ b/drivers/crypto/chelsio/chcr_algo.c > >>> @@ -2351,7 +2351,7 @@ static int chcr_authenc_setkey(struct crypto_aead > >>> *authenc, const u8 *key, > >>> } > >>> out: > >>> aeadctx->enckey_len = 0; > >>> - if (base_hash) > >>> + if (!IS_ERR_OR_NULL(base_hash)) > >>> chcr_free_shash(base_hash); > >> > >> Ah... Ok. Fine, but redo the first patch anyway because it shouldn't > >> ever be NULL. > >> > >> regards, > >> dan carpenter > > > > Hi Dan, > > > > I will update the first patch as you proposed in order to: > > - teach 'chcr_alloc_shash' not to return NULL > > - initialize 'base_hash' with ERR_PTR(-EINVAL) > > - update the above test to !IS_ERR. > > The 2 patches will be merged in only 1. > > > > Thanks for your suggestions. > > Thanks for pointing the error. or You can simply return instead of > goto. Just like that. > > 1.3 @@ -2455,7 +2455,8 @@ static int chcr_authenc_setkey(struct cr > 1.4 base_hash = chcr_alloc_shash(max_authsize); > 1.5 if (IS_ERR(base_hash)) { > 1.6 pr_err("chcr : Base driver cannot be loaded\n"); > 1.7 - goto out; > 1.8 + aeadctx->enckey_len = 0; > 1.9 + return -EINVAL; Don't do that. There should be a goto. regards, dan carpenter