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 574FDC43334 for ; Thu, 9 Jun 2022 05:24:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238312AbiFIFYi (ORCPT ); Thu, 9 Jun 2022 01:24:38 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49648 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238450AbiFIFYa (ORCPT ); Thu, 9 Jun 2022 01:24:30 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7F06CB854; Wed, 8 Jun 2022 22:24:27 -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 dfw.source.kernel.org (Postfix) with ESMTPS id 1B6E861D07; Thu, 9 Jun 2022 05:24:27 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 2C954C34114; Thu, 9 Jun 2022 05:24:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1654752266; bh=gR7Tftbpm2rm+WC0YD9ESf+wexNbl5yDTu6oejUROKo=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=p9xN8uACyHgE4TBurpqUMrazZhTOO7WCxnzZBwK6zSNWSO1JoWukpOw47b8aNjrSX TS/Qns8mKxpVAEKe18gWhZaUGbW1nS+tsLj2OVqdoky/35nf5wGa1aJPXpEz56mS2Q Hnbsx7MQua2CwtHMrlZ4LzJmq3GHsE6iNVz0LiyPEY/siNq/RpfQS6oBjGOiK60Cvk Y332UIEw9MxqvqxVG+7087cxgE75a926Q49m/ORQoMvunjWw1YbNKWKwQdnttYHZaq bh5/GQXo0UE8cNuWKSJCU5zA7kirNBzKLHHb0DbPSfRP3ZTw4HHM8tUiUWoWyRUgBP beWN8V2YZopfA== Date: Thu, 9 Jun 2022 08:22:29 +0300 From: Jarkko Sakkinen To: Jianglei Nie Cc: jejb@linux.ibm.com, zohar@linux.ibm.com, dhowells@redhat.com, jmorris@namei.org, serge@hallyn.com, linux-integrity@vger.kernel.org, keyrings@vger.kernel.org, linux-security-module@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v2] KEYS: trusted: Fix memory leak in tpm2_key_encode() Message-ID: References: <20220608131732.550234-1-niejianglei2021@163.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: keyrings@vger.kernel.org On Thu, Jun 09, 2022 at 08:21:20AM +0300, Jarkko Sakkinen wrote: > On Wed, Jun 08, 2022 at 09:17:32PM +0800, Jianglei Nie wrote: > > tpm2_key_encode() allocates a memory chunk from scratch with kmalloc(), > > but it is never freed, which leads to a memory leak. Free the memory > > chunk with kfree() in the return path. > > > > Signed-off-by: Jianglei Nie > > --- > > You should write down the changelog ere. No idea what changed > from the previous version. > > > security/keys/trusted-keys/trusted_tpm2.c | 23 +++++++++++++++++------ > > 1 file changed, 17 insertions(+), 6 deletions(-) > > > > diff --git a/security/keys/trusted-keys/trusted_tpm2.c b/security/keys/trusted-keys/trusted_tpm2.c > > index 0165da386289..8b7ab22950d1 100644 > > --- a/security/keys/trusted-keys/trusted_tpm2.c > > +++ b/security/keys/trusted-keys/trusted_tpm2.c > > @@ -32,6 +32,7 @@ static int tpm2_key_encode(struct trusted_key_payload *payload, > > struct trusted_key_options *options, > > u8 *src, u32 len) > > { > > + int err; > > Declare as the last local variable (reverse christmas tree order). > > Also, I'd use "int ret" since in other functions that is used. > > > const int SCRATCH_SIZE = PAGE_SIZE; > > u8 *scratch = kmalloc(SCRATCH_SIZE, GFP_KERNEL); > > u8 *work = scratch, *work1; > > @@ -57,8 +58,10 @@ static int tpm2_key_encode(struct trusted_key_payload *payload, > > unsigned char bool[3], *w = bool; > > /* tag 0 is emptyAuth */ > > w = asn1_encode_boolean(w, w + sizeof(bool), true); > > - if (WARN(IS_ERR(w), "BUG: Boolean failed to encode")) > > - return PTR_ERR(w); > > + if (WARN(IS_ERR(w), "BUG: Boolean failed to encode")) { > > + err = PTR_ERR(w); > > + goto out; > > + } > > work = asn1_encode_tag(work, end_work, 0, bool, w - bool); > > } > > > > @@ -69,8 +72,10 @@ static int tpm2_key_encode(struct trusted_key_payload *payload, > > * trigger, so if it does there's something nefarious going on > > */ > > if (WARN(work - scratch + pub_len + priv_len + 14 > SCRATCH_SIZE, > > - "BUG: scratch buffer is too small")) > > - return -EINVAL; > > + "BUG: scratch buffer is too small")) { > > + err = -EINVAL; > > + goto out; > > + } > > > > work = asn1_encode_integer(work, end_work, options->keyhandle); > > work = asn1_encode_octet_string(work, end_work, pub, pub_len); > > @@ -79,10 +84,16 @@ static int tpm2_key_encode(struct trusted_key_payload *payload, > > work1 = payload->blob; > > work1 = asn1_encode_sequence(work1, work1 + sizeof(payload->blob), > > scratch, work - scratch); > > - if (WARN(IS_ERR(work1), "BUG: ASN.1 encoder failed")) > > - return PTR_ERR(work1); > > + if (WARN(IS_ERR(work1), "BUG: ASN.1 encoder failed")) { > > + err = -EINVAL; > > + goto out; > > Why you are changing the return value from PTR_ERR(work1 > to -EINVAL? > > > + } > > + kfree(scratch); > > > > return work1 - payload->blob; > > + > > +out: > > Nit: > > err: > > It's only used for the error path. > > > + return err; > > } > > > > struct tpm2_key_context { > > -- > > 2.25.1 > > > > BR, Jarkko And the patch is also missing fixes tag: Fixes: f2219745250f ("security: keys: trusted: use ASN.1 TPM2 key format for the blobs") BR, Jarkko