Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753169AbdL0Q72 (ORCPT ); Wed, 27 Dec 2017 11:59:28 -0500 Received: from mail.linuxfoundation.org ([140.211.169.12]:36260 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752999AbdL0QtH (ORCPT ); Wed, 27 Dec 2017 11:49:07 -0500 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, syzbot , Stephan Mueller , Jonathan Cameron , Herbert Xu Subject: [PATCH 4.14 38/74] crypto: af_alg - fix race accessing cipher request Date: Wed, 27 Dec 2017 17:46:11 +0100 Message-Id: <20171227164615.613131810@linuxfoundation.org> X-Mailer: git-send-email 2.15.1 In-Reply-To: <20171227164614.109898944@linuxfoundation.org> References: <20171227164614.109898944@linuxfoundation.org> User-Agent: quilt/0.65 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2850 Lines: 87 4.14-stable review patch. If anyone has any objections, please let me know. ------------------ From: Stephan Mueller commit d53c5135792319e095bb126bc43b2ee98586f7fe upstream. When invoking an asynchronous cipher operation, the invocation of the callback may be performed before the subsequent operations in the initial code path are invoked. The callback deletes the cipher request data structure which implies that after the invocation of the asynchronous cipher operation, this data structure must not be accessed any more. The setting of the return code size with the request data structure must therefore be moved before the invocation of the asynchronous cipher operation. Fixes: e870456d8e7c ("crypto: algif_skcipher - overhaul memory management") Fixes: d887c52d6ae4 ("crypto: algif_aead - overhaul memory management") Reported-by: syzbot Signed-off-by: Stephan Mueller Acked-by: Jonathan Cameron Signed-off-by: Herbert Xu Signed-off-by: Greg Kroah-Hartman --- crypto/algif_aead.c | 10 +++++----- crypto/algif_skcipher.c | 10 +++++----- 2 files changed, 10 insertions(+), 10 deletions(-) --- a/crypto/algif_aead.c +++ b/crypto/algif_aead.c @@ -291,6 +291,10 @@ static int _aead_recvmsg(struct socket * /* AIO operation */ sock_hold(sk); areq->iocb = msg->msg_iocb; + + /* Remember output size that will be generated. */ + areq->outlen = outlen; + aead_request_set_callback(&areq->cra_u.aead_req, CRYPTO_TFM_REQ_MAY_BACKLOG, af_alg_async_cb, areq); @@ -298,12 +302,8 @@ static int _aead_recvmsg(struct socket * crypto_aead_decrypt(&areq->cra_u.aead_req); /* AIO operation in progress */ - if (err == -EINPROGRESS || err == -EBUSY) { - /* Remember output size that will be generated. */ - areq->outlen = outlen; - + if (err == -EINPROGRESS || err == -EBUSY) return -EIOCBQUEUED; - } sock_put(sk); } else { --- a/crypto/algif_skcipher.c +++ b/crypto/algif_skcipher.c @@ -125,6 +125,10 @@ static int _skcipher_recvmsg(struct sock /* AIO operation */ sock_hold(sk); areq->iocb = msg->msg_iocb; + + /* Remember output size that will be generated. */ + areq->outlen = len; + skcipher_request_set_callback(&areq->cra_u.skcipher_req, CRYPTO_TFM_REQ_MAY_SLEEP, af_alg_async_cb, areq); @@ -133,12 +137,8 @@ static int _skcipher_recvmsg(struct sock crypto_skcipher_decrypt(&areq->cra_u.skcipher_req); /* AIO operation in progress */ - if (err == -EINPROGRESS || err == -EBUSY) { - /* Remember output size that will be generated. */ - areq->outlen = len; - + if (err == -EINPROGRESS || err == -EBUSY) return -EIOCBQUEUED; - } sock_put(sk); } else {