From: Christophe JAILLET Subject: Re: [PATCH 1/2] crypto: lrw - Fix an error handling path in 'create()' Date: Tue, 10 Oct 2017 08:05:47 +0200 Message-ID: <573ace7e-a5d4-44ef-e6df-9d5fe1e61e6e@wanadoo.fr> References: <53e4cc621176b8aeeb58e493b133be853c66ef49.1507445539.git.christophe.jaillet@wanadoo.fr> <59DBE89C.3090700@bfs.de> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit Cc: herbert@gondor.apana.org.au, davem@davemloft.net, linux-crypto@vger.kernel.org, linux-kernel@vger.kernel.org, kernel-janitors@vger.kernel.org To: wharms@bfs.de Return-path: Received: from smtp06.smtpout.orange.fr ([80.12.242.128]:21490 "EHLO smtp.smtpout.orange.fr" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750950AbdJJGFy (ORCPT ); Tue, 10 Oct 2017 02:05:54 -0400 In-Reply-To: <59DBE89C.3090700@bfs.de> Content-Language: fr Sender: linux-crypto-owner@vger.kernel.org List-ID: Le 09/10/2017 à 23:22, walter harms a écrit : > Am 08.10.2017 11:39, schrieb Christophe JAILLET: >> All error handling paths 'goto err_drop_spawn' except this one. >> In order to avoid some resources leak, we should do it as well here. >> >> Fixes: 700cb3f5fe75 ("crypto: lrw - Convert to skcipher") >> Signed-off-by: Christophe JAILLET >> --- >> crypto/lrw.c | 6 ++++-- >> 1 file changed, 4 insertions(+), 2 deletions(-) >> >> diff --git a/crypto/lrw.c b/crypto/lrw.c >> index a8bfae4451bf..eb681e9fe574 100644 >> --- a/crypto/lrw.c >> +++ b/crypto/lrw.c >> @@ -610,8 +610,10 @@ static int create(struct crypto_template *tmpl, struct rtattr **tb) >> ecb_name[len - 1] = 0; >> >> if (snprintf(inst->alg.base.cra_name, CRYPTO_MAX_ALG_NAME, >> - "lrw(%s)", ecb_name) >= CRYPTO_MAX_ALG_NAME) > this check can be done more easy, > the length of ecb_name is len > the length of inst->alg.base.cra_name is CRYPTO_MAX_ALG_NAME > if CRYPTO_MAX_ALG_NAME-len < "lrw()" < 5 > no need to involve snprintf() > > just my 2 cents > re, > wh It does not only check for the length, it also copies some data. The test should be read: "If the copy succeeds (i.e if there is enough space for the copy to succeed)", and not "if the string is too long". IMHO, the snprintf is just fine here. CJ >> - return -ENAMETOOLONG; >> + "lrw(%s)", ecb_name) >= CRYPTO_MAX_ALG_NAME) { >> + err = -ENAMETOOLONG; >> + goto err_drop_spawn; >> + } >> } >> >> inst->alg.base.cra_flags = alg->base.cra_flags & CRYPTO_ALG_ASYNC;