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 45C10C43334 for ; Thu, 9 Jun 2022 05:23:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238178AbiFIFXS (ORCPT ); Thu, 9 Jun 2022 01:23:18 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43868 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235383AbiFIFXR (ORCPT ); Thu, 9 Jun 2022 01:23:17 -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 507C3E0BF; Wed, 8 Jun 2022 22:23:16 -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 dfw.source.kernel.org (Postfix) with ESMTPS id A7A7961D1F; Thu, 9 Jun 2022 05:23:15 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id A8052C34114; Thu, 9 Jun 2022 05:23:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1654752195; bh=XHZdFhnq6qjYdg5fXbtYu1DYUiXJ7YdR40VwYr8Qwhs=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=S4jNXjOa+bXfsBQgDssKkfORXh7KV4Fv2Qbc1fIUpHJ9pwlQ6mdX+H2LjTz2f+uIU l2a5Dvp03xSxHTGoi0XvVX3+rpg+JNkhEWbTM3hsK8tahLym+j1QiV/FxQZoRJ/luc CCaMTsS/9Guys5kITQ7QS7h1kmAXR6bJcTJn9LHJIhYMyL7fc+AmbrxNqItuGDSPsA m4lf6G+itblmu7MwvAWKxZzOF7YF8Em86E2V6X/X5HpAAhRK1XEbwgDGIza7r7DDsv fzEpaigSTtdKaowngUCwPEirA8QeCLXzXVb3MrzNYaN6BykbvjdEU4iP4JL6kT6h4c LoMbeCq+Sl+kQ== Date: Thu, 9 Jun 2022 08:21:17 +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: <20220608131732.550234-1-niejianglei2021@163.com> Precedence: bulk List-ID: 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