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 X-Spam-Level: X-Spam-Status: No, score=-15.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id A72EFC43462 for ; Mon, 12 Apr 2021 17:04:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 84F06611CE for ; Mon, 12 Apr 2021 17:04:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S243608AbhDLRFK (ORCPT ); Mon, 12 Apr 2021 13:05:10 -0400 Received: from youngberry.canonical.com ([91.189.89.112]:50528 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S245261AbhDLRE6 (ORCPT ); Mon, 12 Apr 2021 13:04:58 -0400 Received: from 1.general.cking.uk.vpn ([10.172.193.212]) by youngberry.canonical.com with esmtpsa (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.86_2) (envelope-from ) id 1lVzzJ-00023K-IM; Mon, 12 Apr 2021 17:04:37 +0000 Subject: Re: [PATCH][next] KEYS: trusted: Fix missing null return from kzalloc call To: jejb@linux.ibm.com, Jarkko Sakkinen , Mimi Zohar , David Howells , James Morris , "Serge E . Hallyn" , Sumit Garg , linux-integrity@vger.kernel.org, keyrings@vger.kernel.org, linux-security-module@vger.kernel.org Cc: kernel-janitors@vger.kernel.org, linux-kernel@vger.kernel.org References: <20210412160101.1627882-1-colin.king@canonical.com> From: Colin Ian King Message-ID: <53fef8cf-0dd4-e4fe-260b-0f5ad25d9014@canonical.com> Date: Mon, 12 Apr 2021 18:04:37 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.8.1 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: On 12/04/2021 17:48, James Bottomley wrote: > On Mon, 2021-04-12 at 17:01 +0100, Colin King wrote: >> From: Colin Ian King >> >> The kzalloc call can return null with the GFP_KERNEL flag so >> add a null check and exit via a new error exit label. Use the >> same exit error label for another error path too. >> >> Addresses-Coverity: ("Dereference null return value") >> Fixes: 830027e2cb55 ("KEYS: trusted: Add generic trusted keys >> framework") >> Signed-off-by: Colin Ian King >> --- >> security/keys/trusted-keys/trusted_core.c | 6 ++++-- >> 1 file changed, 4 insertions(+), 2 deletions(-) >> >> diff --git a/security/keys/trusted-keys/trusted_core.c >> b/security/keys/trusted-keys/trusted_core.c >> index ec3a066a4b42..90774793f0b1 100644 >> --- a/security/keys/trusted-keys/trusted_core.c >> +++ b/security/keys/trusted-keys/trusted_core.c >> @@ -116,11 +116,13 @@ static struct trusted_key_payload >> *trusted_payload_alloc(struct key *key) >> >> ret = key_payload_reserve(key, sizeof(*p)); >> if (ret < 0) >> - return p; >> + goto err; >> p = kzalloc(sizeof(*p), GFP_KERNEL); >> + if (!p) >> + goto err; >> >> p->migratable = migratable; >> - >> +err: >> return p; > > This is clearly a code migration bug in > > commit 251c85bd106099e6f388a89e88e12d14de2c9cda > Author: Sumit Garg > Date: Mon Mar 1 18:41:24 2021 +0530 > > KEYS: trusted: Add generic trusted keys framework > > Which has for addition to trusted_core.c: > > +static struct trusted_key_payload *trusted_payload_alloc(struct key > *key) > +{ > + struct trusted_key_payload *p = NULL; > + int ret; > + > + ret = key_payload_reserve(key, sizeof(*p)); > + if (ret < 0) > + return p; > + p = kzalloc(sizeof(*p), GFP_KERNEL); > + > + p->migratable = migratable; > + > + return p; > +} > > And for trusted_tpm1.c: > > -static struct trusted_key_payload *trusted_payload_alloc(struct key > *key) > -{ > - struct trusted_key_payload *p = NULL; > - int ret; > - > - ret = key_payload_reserve(key, sizeof *p); > - if (ret < 0) > - return p; > - p = kzalloc(sizeof *p, GFP_KERNEL); > - if (p) > - p->migratable = 1; /* migratable by default */ > - return p; > -} > > The trusted_tpm1.c code was correct and we got this bug introduced by > what should have been a simple cut and paste ... how did that happen? > And therefore, how safe is the rest of the extraction into > trusted_core.c? > fortunately it gets caught by static analysis, but it does make me also concerned about what else has changed and how this gets through review. > James > >