From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dan Carpenter Date: Thu, 09 Jul 2020 10:48:18 +0000 Subject: [PATCH] kernel/smp: Fix an off by one in csd_lock_wait_toolong() Message-Id: <20200709104818.GC20875@mwanda> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Peter Zijlstra Cc: Ingo Molnar , Thomas Gleixner , Sebastian Andrzej Siewior , "Paul E. McKenney" , Kaitao Cheng , linux-kernel@vger.kernel.org, kernel-janitors@vger.kernel.org The __per_cpu_offset[] array has "nr_cpu_ids" elements so change the > >= to prevent a read one element beyond the end of the array. Fixes: 0504bc41a62c ("kernel/smp: Provide CSD lock timeout diagnostics") Signed-off-by: Dan Carpenter --- kernel/smp.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kernel/smp.c b/kernel/smp.c index 78b602cae6c2..f49966713ac3 100644 --- a/kernel/smp.c +++ b/kernel/smp.c @@ -171,7 +171,7 @@ static __always_inline bool csd_lock_wait_toolong(call_single_data_t *csd, u64 t *bug_id = atomic_inc_return(&csd_bug_count); cpu = csd_lock_wait_getcpu(csd); smp_mb(); // No stale cur_csd values! - if (WARN_ONCE(cpu < 0 || cpu > nr_cpu_ids, "%s: cpu = %d\n", __func__, cpu)) + if (WARN_ONCE(cpu < 0 || cpu >= nr_cpu_ids, "%s: cpu = %d\n", __func__, cpu)) cpu_cur_csd = READ_ONCE(per_cpu(cur_csd, 0)); else cpu_cur_csd = READ_ONCE(per_cpu(cur_csd, cpu)); -- 2.27.0 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=-6.8 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 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 B2A6CC433DF for ; Thu, 9 Jul 2020 10:48:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9092A206DF for ; Thu, 9 Jul 2020 10:48:47 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=oracle.com header.i=@oracle.com header.b="BB43mlIw" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726819AbgGIKsq (ORCPT ); Thu, 9 Jul 2020 06:48:46 -0400 Received: from aserp2120.oracle.com ([141.146.126.78]:57876 "EHLO aserp2120.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726302AbgGIKsq (ORCPT ); Thu, 9 Jul 2020 06:48:46 -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 069AhASW036413; Thu, 9 Jul 2020 10:48:29 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.com; h=date : from : to : cc : subject : message-id : mime-version : content-type; s=corp-2020-01-29; bh=7sknyjhzQrM3Ihcf3HJ+ICn6zVC4BBDBp0IR1uUH0Mk=; b=BB43mlIwUowlPq4vKUk233c/HUqjekEIwyqgve4Xd26HMEDnZ/8Iq5S4DebbsiQ177IK h0N25EdywmDw+czkC0nayGWQJgSHvD2L/yma6d/kojnp/PLkDD1Aw/16ylvhCYUiYpDd yOd4XZkgbGsf/zOfZ0i8bDEwLjcdzXkbLoWKwlgAWEne5KXOE/NaIV5Jp7IkJr86Daqw HWf3AECsHO1WIRtuI6ijCEC0seuc40m5Iu8PzResNhCkbJ16TVwGr7pl7yxkgbExjTAv AG0nQHSK2JULAIdjbM2oxqFkiKJ6A1iG1PXDAx0WDH0jklAHTL/PgcS/77tmjOzRJ1+r ow== Received: from userp3020.oracle.com (userp3020.oracle.com [156.151.31.79]) by aserp2120.oracle.com with ESMTP id 325y0agwv2-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=FAIL); Thu, 09 Jul 2020 10:48:29 +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 069AhJ0u059975; Thu, 9 Jul 2020 10:48:28 GMT Received: from aserv0121.oracle.com (aserv0121.oracle.com [141.146.126.235]) by userp3020.oracle.com with ESMTP id 325k3h03pg-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Thu, 09 Jul 2020 10:48:28 +0000 Received: from abhmp0002.oracle.com (abhmp0002.oracle.com [141.146.116.8]) by aserv0121.oracle.com (8.14.4/8.13.8) with ESMTP id 069AmPFk023768; Thu, 9 Jul 2020 10:48:25 GMT Received: from mwanda (/41.57.98.10) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Thu, 09 Jul 2020 03:48:25 -0700 Date: Thu, 9 Jul 2020 13:48:18 +0300 From: Dan Carpenter To: Peter Zijlstra Cc: Ingo Molnar , Thomas Gleixner , Sebastian Andrzej Siewior , "Paul E. McKenney" , Kaitao Cheng , linux-kernel@vger.kernel.org, kernel-janitors@vger.kernel.org Subject: [PATCH] kernel/smp: Fix an off by one in csd_lock_wait_toolong() Message-ID: <20200709104818.GC20875@mwanda> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline X-Mailer: git-send-email haha only kidding X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9676 signatures=668680 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 adultscore=0 bulkscore=0 mlxscore=0 spamscore=0 malwarescore=0 phishscore=0 mlxlogscore=999 suspectscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2006250000 definitions=main-2007090085 X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9676 signatures=668680 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 adultscore=0 mlxscore=0 priorityscore=1501 spamscore=0 phishscore=0 clxscore=1011 mlxlogscore=999 lowpriorityscore=0 malwarescore=0 bulkscore=0 suspectscore=0 impostorscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2006250000 definitions=main-2007090085 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The __per_cpu_offset[] array has "nr_cpu_ids" elements so change the > >= to prevent a read one element beyond the end of the array. Fixes: 0504bc41a62c ("kernel/smp: Provide CSD lock timeout diagnostics") Signed-off-by: Dan Carpenter --- kernel/smp.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kernel/smp.c b/kernel/smp.c index 78b602cae6c2..f49966713ac3 100644 --- a/kernel/smp.c +++ b/kernel/smp.c @@ -171,7 +171,7 @@ static __always_inline bool csd_lock_wait_toolong(call_single_data_t *csd, u64 t *bug_id = atomic_inc_return(&csd_bug_count); cpu = csd_lock_wait_getcpu(csd); smp_mb(); // No stale cur_csd values! - if (WARN_ONCE(cpu < 0 || cpu > nr_cpu_ids, "%s: cpu = %d\n", __func__, cpu)) + if (WARN_ONCE(cpu < 0 || cpu >= nr_cpu_ids, "%s: cpu = %d\n", __func__, cpu)) cpu_cur_csd = READ_ONCE(per_cpu(cur_csd, 0)); else cpu_cur_csd = READ_ONCE(per_cpu(cur_csd, cpu)); -- 2.27.0