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=-8.4 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,UNPARSEABLE_RELAY, 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 2A3E3C433DF for ; Wed, 3 Jun 2020 11:09:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 09300206C3 for ; Wed, 3 Jun 2020 11:09:48 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=oracle.com header.i=@oracle.com header.b="gNkQFmyY" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725937AbgFCLJq (ORCPT ); Wed, 3 Jun 2020 07:09:46 -0400 Received: from aserp2120.oracle.com ([141.146.126.78]:60502 "EHLO aserp2120.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725855AbgFCLJq (ORCPT ); Wed, 3 Jun 2020 07:09:46 -0400 Received: from pps.filterd (aserp2120.oracle.com [127.0.0.1]) by aserp2120.oracle.com (8.16.0.42/8.16.0.42) with SMTP id 053B2k4m044142; Wed, 3 Jun 2020 11:09:32 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.com; h=date : from : to : cc : subject : message-id : references : mime-version : content-type : content-transfer-encoding : in-reply-to; s=corp-2020-01-29; bh=/1lXnyJGE3rK0PHjfgcnam/gH7evUeSV7+Brat7xl18=; b=gNkQFmyY4NoTebljnZ3gEWxSdEnZIRjcnYCf7/cN6kgXeuxsQLF7IDFjkw1s0kY+PCUI EzfgzOcGQV2Y2oDKY0LGACOhyMrzKMlLRVYjmhrYaIQL792BRl9z5FwXcSdZGqxcC09B Ca97bvhy7EzqaGc4wmOfd8fsbU9yzBEzu/zBM6YvcQJg8AuE0U9qBg52qjjyWroX/00J a5t4e5a77EBat7KzEzyCyMgOCevsVr4p/rAaS9rM8hjNseVk88R+nDgQr+dx98d0Q+hl okXQrT0hdzgvxsq+giKHPBi9IY9lqzHkHwZQSAEzCMicfu5qq005FZ9DcDvSnSuXBxJ2 jA== Received: from userp3020.oracle.com (userp3020.oracle.com [156.151.31.79]) by aserp2120.oracle.com with ESMTP id 31bfem8mch-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=FAIL); Wed, 03 Jun 2020 11:09:32 +0000 Received: from pps.filterd (userp3020.oracle.com [127.0.0.1]) by userp3020.oracle.com (8.16.0.42/8.16.0.42) with SMTP id 053B42hO130012; Wed, 3 Jun 2020 11:09:31 GMT Received: from userv0122.oracle.com (userv0122.oracle.com [156.151.31.75]) by userp3020.oracle.com with ESMTP id 31dju32h3s-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Wed, 03 Jun 2020 11:09:31 +0000 Received: from abhmp0019.oracle.com (abhmp0019.oracle.com [141.146.116.25]) by userv0122.oracle.com (8.14.4/8.14.4) with ESMTP id 053B9RT3020500; Wed, 3 Jun 2020 11:09:27 GMT Received: from kadam (/41.57.98.10) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Wed, 03 Jun 2020 04:09:26 -0700 Date: Wed, 3 Jun 2020 14:09:19 +0300 From: Dan Carpenter To: Stephan =?iso-8859-1?Q?M=FCller?= Cc: davem@davemloft.net, herbert@gondor.apana.org.au, linux-crypto@vger.kernel.org, linux-kernel@vger.kernel.org, syzkaller-bugs@googlegroups.com, syzbot Subject: Re: [PATCH] crypto: DRBG - always try to free Jitter RNG instance Message-ID: <20200603110919.GK30374@kadam> References: <0000000000002a280b05a725cd93@google.com> <2583872.mvXUDI8C0e@positron.chronox.de> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <2583872.mvXUDI8C0e@positron.chronox.de> User-Agent: Mutt/1.9.4 (2018-02-28) X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9640 signatures=668686 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 spamscore=0 mlxlogscore=999 phishscore=0 malwarescore=0 mlxscore=0 adultscore=0 bulkscore=0 suspectscore=2 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2004280000 definitions=main-2006030087 X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9640 signatures=668686 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 malwarescore=0 suspectscore=2 mlxlogscore=999 priorityscore=1501 bulkscore=0 phishscore=0 clxscore=1011 impostorscore=0 adultscore=0 spamscore=0 mlxscore=0 lowpriorityscore=0 cotscore=-2147483648 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2004280000 definitions=main-2006030087 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Jun 03, 2020 at 10:08:56AM +0200, Stephan Müller wrote: > The Jitter RNG is unconditionally allocated as a seed source follwoing > the patch 97f2650e5040. Thus, the instance must always be deallocated. > > Reported-by: syzbot+2e635807decef724a1fa@syzkaller.appspotmail.com > Fixes: 97f2650e5040 ("crypto: drbg - always seeded with SP800-90B ...") > Signed-off-by: Stephan Mueller > --- > crypto/drbg.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/crypto/drbg.c b/crypto/drbg.c > index 37526eb8c5d5..33d28016da2d 100644 > --- a/crypto/drbg.c > +++ b/crypto/drbg.c > @@ -1631,6 +1631,9 @@ static int drbg_uninstantiate(struct drbg_state *drbg) > if (drbg->random_ready.func) { > del_random_ready_callback(&drbg->random_ready); > cancel_work_sync(&drbg->seed_work); > + } > + > + if (drbg->jent) { > crypto_free_rng(drbg->jent); > drbg->jent = NULL; > } free_everything functions never work. For example, "drbg->jent" can be an error pointer at this point. crypto/drbg.c 1577 if (!drbg->core) { 1578 drbg->core = &drbg_cores[coreref]; 1579 drbg->pr = pr; 1580 drbg->seeded = false; 1581 drbg->reseed_threshold = drbg_max_requests(drbg); 1582 1583 ret = drbg_alloc_state(drbg); 1584 if (ret) 1585 goto unlock; 1586 1587 ret = drbg_prepare_hrng(drbg); 1588 if (ret) 1589 goto free_everything; ^^^^^^^^^^^^^^^^^^^^ If we hit two failures inside drbg_prepare_hrng() then "drbg->jent" can be an error pointer. 1590 1591 if (IS_ERR(drbg->jent)) { 1592 ret = PTR_ERR(drbg->jent); 1593 drbg->jent = NULL; 1594 if (fips_enabled || ret != -ENOENT) 1595 goto free_everything; 1596 pr_info("DRBG: Continuing without Jitter RNG\n"); 1597 } 1598 1599 reseed = false; 1600 } 1601 1602 ret = drbg_seed(drbg, pers, reseed); 1603 1604 if (ret && !reseed) 1605 goto free_everything; 1606 1607 mutex_unlock(&drbg->drbg_mutex); 1608 return ret; 1609 1610 unlock: 1611 mutex_unlock(&drbg->drbg_mutex); 1612 return ret; 1613 1614 free_everything: 1615 mutex_unlock(&drbg->drbg_mutex); 1616 drbg_uninstantiate(drbg); ^^^^ Leading to an Oops. 1617 return ret; 1618 } regards, dan carpenter