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=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS autolearn=no 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 0070BC55178 for ; Tue, 27 Oct 2020 13:42:15 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B775321D24 for ; Tue, 27 Oct 2020 13:42:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1603806134; bh=mtEJCuoSdc73aurMY0TyokcE6mPezNNe7WhapKj0JwA=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=pduuiMqmkHGy251xroY0Zub4RJaCaQnH6HMPIsk1Le96PqCa2l+7IhfsyNEp64IHy n6+kqqCmAB097wTUSpYX0+UfQZXCudOrXO7Ax9DZZW+pjUsNfGvUIvAQVg9XghMS2B fv2lj/zyKDGapvLZjtT7gELcpkaSzib1RARNxrPI= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752438AbgJ0NmN (ORCPT ); Tue, 27 Oct 2020 09:42:13 -0400 Received: from mail.kernel.org ([198.145.29.99]:39230 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752429AbgJ0NmJ (ORCPT ); Tue, 27 Oct 2020 09:42:09 -0400 Received: from localhost (83-86-74-64.cable.dynamic.v4.ziggo.nl [83.86.74.64]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 7717B218AC; Tue, 27 Oct 2020 13:42:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1603806129; bh=mtEJCuoSdc73aurMY0TyokcE6mPezNNe7WhapKj0JwA=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=x/0a/eDRtMESG5dvHG7Ebk6v+1KyL2PE98bgdKvsTJucEr9WrZ960pdCAlecqND2L ascb8Jc9LV+j5rtyjxzEjFQ/Eb1DuS6p822KTmPxwQscRT3YUX23uEYb2Cm3w6OE6G 2YBMMVop3p0QDWR6v0K8F55DA1idgIMp/Bq90gdg= Date: Tue, 27 Oct 2020 14:42:43 +0100 From: Greg KH To: Matteo Croce Cc: linux-kernel@vger.kernel.org, Guenter Roeck , Petr Mladek , Arnd Bergmann , Mike Rapoport , Kees Cook , Pavel Tatashin , Robin Holt , Fabian Frederick , stable@vger.kernel.org Subject: Re: [PATCH v2 1/2] reboot: fix overflow parsing reboot cpu number Message-ID: <20201027134243.GC991306@kroah.com> References: <20201027133545.58625-1-mcroce@linux.microsoft.com> <20201027133545.58625-2-mcroce@linux.microsoft.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20201027133545.58625-2-mcroce@linux.microsoft.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Oct 27, 2020 at 02:35:44PM +0100, Matteo Croce wrote: > From: Matteo Croce > > Limit the CPU number to num_possible_cpus(), because setting it > to a value lower than INT_MAX but higher than NR_CPUS produces the > following error on reboot and shutdown: > > BUG: unable to handle page fault for address: ffffffff90ab1bb0 > #PF: supervisor read access in kernel mode > #PF: error_code(0x0000) - not-present page > PGD 1c09067 P4D 1c09067 PUD 1c0a063 PMD 0 > Oops: 0000 [#1] SMP > CPU: 1 PID: 1 Comm: systemd-shutdow Not tainted 5.9.0-rc8-kvm #110 > Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.13.0-2.fc32 04/01/2014 > RIP: 0010:migrate_to_reboot_cpu+0xe/0x60 > Code: ea ea 00 48 89 fa 48 c7 c7 30 57 f1 81 e9 fa ef ff ff 66 2e 0f 1f 84 00 00 00 00 00 53 8b 1d d5 ea ea 00 e8 14 33 fe ff 89 da <48> 0f a3 15 ea fc bd 00 48 89 d0 73 29 89 c2 c1 e8 06 65 48 8b 3c > RSP: 0018:ffffc90000013e08 EFLAGS: 00010246 > RAX: ffff88801f0a0000 RBX: 0000000077359400 RCX: 0000000000000000 > RDX: 0000000077359400 RSI: 0000000000000002 RDI: ffffffff81c199e0 > RBP: ffffffff81c1e3c0 R08: ffff88801f41f000 R09: ffffffff81c1e348 > R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 > R13: 00007f32bedf8830 R14: 00000000fee1dead R15: 0000000000000000 > FS: 00007f32bedf8980(0000) GS:ffff88801f480000(0000) knlGS:0000000000000000 > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > CR2: ffffffff90ab1bb0 CR3: 000000001d057000 CR4: 00000000000006a0 > DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 > DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 > Call Trace: > __do_sys_reboot.cold+0x34/0x5b > ? vfs_writev+0x92/0xc0 > ? do_writev+0x52/0xd0 > do_syscall_64+0x2d/0x40 > entry_SYSCALL_64_after_hwframe+0x44/0xa9 > RIP: 0033:0x7f32bfaaecd3 > Code: 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 89 fa be 69 19 12 28 bf ad de e1 fe b8 a9 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 05 c3 0f 1f 40 00 48 8b 15 89 81 0c 00 f7 d8 > RSP: 002b:00007fff6265fb58 EFLAGS: 00000202 ORIG_RAX: 00000000000000a9 > RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f32bfaaecd3 > RDX: 0000000001234567 RSI: 0000000028121969 RDI: 00000000fee1dead > RBP: 0000000000000000 R08: 0000000000008020 R09: 00007fff6265ef60 > R10: 00007f32bedf8830 R11: 0000000000000202 R12: 0000000000000000 > R13: 0000557bba2c51c0 R14: 0000000000000000 R15: 00007fff6265fbc8 > CR2: ffffffff90ab1bb0 > ---[ end trace b813e80157136563 ]--- > RIP: 0010:migrate_to_reboot_cpu+0xe/0x60 > Code: ea ea 00 48 89 fa 48 c7 c7 30 57 f1 81 e9 fa ef ff ff 66 2e 0f 1f 84 00 00 00 00 00 53 8b 1d d5 ea ea 00 e8 14 33 fe ff 89 da <48> 0f a3 15 ea fc bd 00 48 89 d0 73 29 89 c2 c1 e8 06 65 48 8b 3c > RSP: 0018:ffffc90000013e08 EFLAGS: 00010246 > RAX: ffff88801f0a0000 RBX: 0000000077359400 RCX: 0000000000000000 > RDX: 0000000077359400 RSI: 0000000000000002 RDI: ffffffff81c199e0 > RBP: ffffffff81c1e3c0 R08: ffff88801f41f000 R09: ffffffff81c1e348 > R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 > R13: 00007f32bedf8830 R14: 00000000fee1dead R15: 0000000000000000 > FS: 00007f32bedf8980(0000) GS:ffff88801f480000(0000) knlGS:0000000000000000 > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > CR2: ffffffff90ab1bb0 CR3: 000000001d057000 CR4: 00000000000006a0 > DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 > DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 > Kernel panic - not syncing: Attempted to kill init! exitcode=0x00000009 > Kernel Offset: disabled > ---[ end Kernel panic - not syncing: Attempted to kill init! exitcode=0x00000009 ]--- > > Fixes: 1b3a5d02ee07 ("reboot: move arch/x86 reboot= handling to generic kernel") > Signed-off-by: Matteo Croce > --- > kernel/reboot.c | 8 ++++++++ > 1 file changed, 8 insertions(+) > This is not the correct way to submit patches for inclusion in the stable kernel tree. Please read: https://www.kernel.org/doc/html/latest/process/stable-kernel-rules.html for how to do this properly.