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=-19.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT 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 0E856C2B9F4 for ; Mon, 28 Jun 2021 14:24:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id DCB39613C3 for ; Mon, 28 Jun 2021 14:24:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233809AbhF1O0v (ORCPT ); Mon, 28 Jun 2021 10:26:51 -0400 Received: from mail.kernel.org ([198.145.29.99]:54380 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233327AbhF1OWD (ORCPT ); Mon, 28 Jun 2021 10:22:03 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id B015561C76; Mon, 28 Jun 2021 14:19:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1624889968; bh=+TRSkwqynGvow4YcvPMYfb1aTa2wCIrpixh1uDyMy6Q=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=NyouYkqBbM5sO8B3OgTNplTha5M7FRN45092wSfLhPQ6gzRoRfv4Me4uTbGgZ0Rkn uNZK0QZFKhld7mO4OhL3LFtOStsycqwMl6SjFFEW96B9XVtItOP+bWHMOR0iGIr1Fr /cr4GzvNuZ7DHT6WjiqUCE3MJg9wCJvF2YqTI480QNLerCaeA8i5FO8bR/Cp1434wo aya870bah8pUwKK1idNzA5okgvsN0cM1v07vf5LQBSw/MDq8O45lBeMugXRyJO0G1f Lf4QspTLiX07kd5DAZ9lrLWYuIGgj9LXv7mHyRYiL/OdXtTdClSfKxiCVxcuBlHcKc /QCYXASwErLWg== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Sven Schnelle , stable@kernel.org, Marius Hillenbrand , Heiko Carstens , Vasily Gorbik , Greg Kroah-Hartman Subject: [PATCH 5.12 069/110] s390/topology: clear thread/group maps for offline cpus Date: Mon, 28 Jun 2021 10:17:47 -0400 Message-Id: <20210628141828.31757-70-sashal@kernel.org> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20210628141828.31757-1-sashal@kernel.org> References: <20210628141828.31757-1-sashal@kernel.org> MIME-Version: 1.0 X-KernelTest-Patch: http://kernel.org/pub/linux/kernel/v5.x/stable-review/patch-5.12.14-rc1.gz X-KernelTest-Tree: git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable-rc.git X-KernelTest-Branch: linux-5.12.y X-KernelTest-Patches: git://git.kernel.org/pub/scm/linux/kernel/git/stable/stable-queue.git X-KernelTest-Version: 5.12.14-rc1 X-KernelTest-Deadline: 2021-06-30T14:18+00:00 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Sven Schnelle commit 9e3d62d55bf455d4f9fdf2ede5c8756410c64102 upstream. The current code doesn't clear the thread/group maps for offline CPUs. This may cause kernel crashes like the one bewlow in common code that assumes if a CPU has sibblings it is online. Unable to handle kernel pointer dereference in virtual kernel address space Call Trace: [<000000013a4b8c3c>] blk_mq_map_swqueue+0x10c/0x388 ([<000000013a4b8bcc>] blk_mq_map_swqueue+0x9c/0x388) [<000000013a4b9300>] blk_mq_init_allocated_queue+0x448/0x478 [<000000013a4b9416>] blk_mq_init_queue+0x4e/0x90 [<000003ff8019d3e6>] loop_add+0x106/0x278 [loop] [<000003ff801b8148>] loop_init+0x148/0x1000 [loop] [<0000000139de4924>] do_one_initcall+0x3c/0x1e0 [<0000000139ef449a>] do_init_module+0x6a/0x2a0 [<0000000139ef61bc>] __do_sys_finit_module+0xa4/0xc0 [<0000000139de9e6e>] do_syscall+0x7e/0xd0 [<000000013a8e0aec>] __do_syscall+0xbc/0x110 [<000000013a8ee2e8>] system_call+0x78/0xa0 Fixes: 52aeda7accb6 ("s390/topology: remove offline CPUs from CPU topology masks") Cc: # 5.7+ Reported-by: Marius Hillenbrand Signed-off-by: Sven Schnelle Reviewed-by: Heiko Carstens Signed-off-by: Vasily Gorbik Signed-off-by: Greg Kroah-Hartman --- arch/s390/kernel/topology.c | 12 +++++++++--- 1 file changed, 9 insertions(+), 3 deletions(-) diff --git a/arch/s390/kernel/topology.c b/arch/s390/kernel/topology.c index bfcc327acc6b..26aa2614ee35 100644 --- a/arch/s390/kernel/topology.c +++ b/arch/s390/kernel/topology.c @@ -66,7 +66,10 @@ static void cpu_group_map(cpumask_t *dst, struct mask_info *info, unsigned int c { static cpumask_t mask; - cpumask_copy(&mask, cpumask_of(cpu)); + cpumask_clear(&mask); + if (!cpu_online(cpu)) + goto out; + cpumask_set_cpu(cpu, &mask); switch (topology_mode) { case TOPOLOGY_MODE_HW: while (info) { @@ -83,10 +86,10 @@ static void cpu_group_map(cpumask_t *dst, struct mask_info *info, unsigned int c default: fallthrough; case TOPOLOGY_MODE_SINGLE: - cpumask_copy(&mask, cpumask_of(cpu)); break; } cpumask_and(&mask, &mask, cpu_online_mask); +out: cpumask_copy(dst, &mask); } @@ -95,7 +98,10 @@ static void cpu_thread_map(cpumask_t *dst, unsigned int cpu) static cpumask_t mask; int i; - cpumask_copy(&mask, cpumask_of(cpu)); + cpumask_clear(&mask); + if (!cpu_online(cpu)) + goto out; + cpumask_set_cpu(cpu, &mask); if (topology_mode != TOPOLOGY_MODE_HW) goto out; cpu -= cpu % (smp_cpu_mtid + 1); -- 2.30.2