From patchwork Sun Jun 13 10:54:56 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Haren Myneni X-Patchwork-Id: 459587 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=-13.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER, INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS autolearn=ham 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 98993C48BCF for ; Sun, 13 Jun 2021 10:55:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6B53B61042 for ; Sun, 13 Jun 2021 10:55:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231659AbhFMK5N (ORCPT ); Sun, 13 Jun 2021 06:57:13 -0400 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:5962 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S231176AbhFMK5N (ORCPT ); Sun, 13 Jun 2021 06:57:13 -0400 Received: from pps.filterd (m0098419.ppops.net [127.0.0.1]) by mx0b-001b2d01.pphosted.com (8.16.0.43/8.16.0.43) with SMTP id 15DAn0O5023430; Sun, 13 Jun 2021 06:55:03 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ibm.com; h=message-id : subject : from : to : cc : date : in-reply-to : references : content-type : mime-version : content-transfer-encoding; s=pp1; bh=KTtX+syhVsp3EKtNv4+mXEMJYwINd+QKLT2o6wNy4jk=; b=kS8ZAQbjvNaLDjLDZgzICTL1STDSzX34q9jBE6VaA3yOrbRhtOKOkIvJnprYHMaVkBDv mr1GHRT9twQk2QHqu07rHJ/2i1fvGREKPrGsdYxJ3VKLYbtNczulrdz4sGemInDEOkno pbFe3YIu6YBSjKGQndHVINE6l78UXxeyOLHO5ZwEWOwYiKj+1hVZNcrqitj+neuDgHDH XGBndFAOHEKFengp54ARmxiA4KG4fXiCRCjugEKIT1rAbRNlKr7suHwfOTdFUliVyR4s +atkqiRCY6A3KDJLC7aQ7Gmby7ZRKNuZNiUliouAig5Uioh55Sy7XoNZ4xRVLcUEW2qY cA== Received: from pps.reinject (localhost [127.0.0.1]) by mx0b-001b2d01.pphosted.com with ESMTP id 395gkpg1k4-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Sun, 13 Jun 2021 06:55:03 -0400 Received: from m0098419.ppops.net (m0098419.ppops.net [127.0.0.1]) by pps.reinject (8.16.0.43/8.16.0.43) with SMTP id 15DAr9kd035212; Sun, 13 Jun 2021 06:55:02 -0400 Received: from ppma04dal.us.ibm.com (7a.29.35a9.ip4.static.sl-reverse.com [169.53.41.122]) by mx0b-001b2d01.pphosted.com with ESMTP id 395gkpg1jt-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Sun, 13 Jun 2021 06:55:02 -0400 Received: from pps.filterd (ppma04dal.us.ibm.com [127.0.0.1]) by ppma04dal.us.ibm.com (8.16.1.2/8.16.1.2) with SMTP id 15DAqBBZ006317; Sun, 13 Jun 2021 10:55:02 GMT Received: from b03cxnp07028.gho.boulder.ibm.com (b03cxnp07028.gho.boulder.ibm.com [9.17.130.15]) by ppma04dal.us.ibm.com with ESMTP id 394yr5pbnu-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Sun, 13 Jun 2021 10:55:02 +0000 Received: from b03ledav003.gho.boulder.ibm.com (b03ledav003.gho.boulder.ibm.com [9.17.130.234]) by b03cxnp07028.gho.boulder.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 15DAt0Kq27918642 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Sun, 13 Jun 2021 10:55:00 GMT Received: from b03ledav003.gho.boulder.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id BEF466A051; Sun, 13 Jun 2021 10:55:00 +0000 (GMT) Received: from b03ledav003.gho.boulder.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 238986A04D; Sun, 13 Jun 2021 10:54:59 +0000 (GMT) Received: from localhost.localdomain (unknown [9.160.180.39]) by b03ledav003.gho.boulder.ibm.com (Postfix) with ESMTP; Sun, 13 Jun 2021 10:54:58 +0000 (GMT) Message-ID: <4c769385e96a9b7022a4fd22938310550ceba5e1.camel@linux.ibm.com> Subject: [PATCH v5 01/17] powerpc/powernv/vas: Release reference to tgid during window close From: Haren Myneni To: linuxppc-dev@lists.ozlabs.org, linux-crypto@vger.kernel.org, mpe@ellerman.id.au, herbert@gondor.apana.org.au, npiggin@gmail.com Cc: hbabu@us.ibm.com, haren@us.ibm.com Date: Sun, 13 Jun 2021 03:54:56 -0700 In-Reply-To: References: User-Agent: Evolution 3.36.2 (3.36.2-1.fc32) MIME-Version: 1.0 X-TM-AS-GCONF: 00 X-Proofpoint-GUID: 2fyfXEnR7sHKJSospIzRKF0qXBqDUzLi X-Proofpoint-ORIG-GUID: iKiSzB4omFD8P9ucoroSCvN6kIQuuIuk X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.391, 18.0.761 definitions=2021-06-13_04:2021-06-11,2021-06-13 signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 mlxlogscore=999 impostorscore=0 phishscore=0 lowpriorityscore=0 suspectscore=0 bulkscore=0 mlxscore=0 priorityscore=1501 clxscore=1015 malwarescore=0 spamscore=0 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2104190000 definitions=main-2106130078 Precedence: bulk List-ID: X-Mailing-List: linux-crypto@vger.kernel.org The kernel handles the NX fault by updating CSB or sending signal to process. In multithread applications, children can open VAS windows and can exit without closing them. But the parent can continue to send NX requests with these windows. To prevent pid reuse, reference will be taken on pid and tgid when the window is opened and release them during window close. The current code is not releasing the tgid reference which can cause pid leak and this patch fixes the issue. Fixes: db1c08a740635 ("powerpc/vas: Take reference to PID and mm for user space windows") Cc: stable@vger.kernel.org # 5.8+ Signed-off-by: Haren Myneni Reported-by: Nicholas Piggin Reviewed-by: Nicholas Piggin --- arch/powerpc/platforms/powernv/vas-window.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/arch/powerpc/platforms/powernv/vas-window.c b/arch/powerpc/platforms/powernv/vas-window.c index 5f5fe63a3d1c..7ba0840fc3b5 100644 --- a/arch/powerpc/platforms/powernv/vas-window.c +++ b/arch/powerpc/platforms/powernv/vas-window.c @@ -1093,9 +1093,9 @@ struct vas_window *vas_tx_win_open(int vasid, enum vas_cop_type cop, /* * Process closes window during exit. In the case of * multithread application, the child thread can open - * window and can exit without closing it. Expects parent - * thread to use and close the window. So do not need - * to take pid reference for parent thread. + * window and can exit without closing it. so takes tgid + * reference until window closed to make sure tgid is not + * reused. */ txwin->tgid = find_get_pid(task_tgid_vnr(current)); /* @@ -1339,8 +1339,9 @@ int vas_win_close(struct vas_window *window) /* if send window, drop reference to matching receive window */ if (window->tx_win) { if (window->user_win) { - /* Drop references to pid and mm */ + /* Drop references to pid. tgid and mm */ put_pid(window->pid); + put_pid(window->tgid); if (window->mm) { mm_context_remove_vas_window(window->mm); mmdrop(window->mm);