From patchwork Thu Apr 14 13:13:28 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 562217 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 59BF8C43219 for ; Thu, 14 Apr 2022 14:13:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240780AbiDNOOK (ORCPT ); Thu, 14 Apr 2022 10:14:10 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43184 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1347444AbiDNN6y (ORCPT ); Thu, 14 Apr 2022 09:58:54 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id ABF333BFB8; Thu, 14 Apr 2022 06:49:45 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 1F05D6190F; Thu, 14 Apr 2022 13:49:45 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 2FE5AC385A9; Thu, 14 Apr 2022 13:49:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1649944184; bh=9oFNcS7HJs4dteFnR58k+fmQF3XjZJBJD9RXkCPTpYE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=VsLgwbfOu4HqGrQgDLCnoma0LC0Eu6lukpDl5ab2I2SYUd3CXNktCygGhOF3BCYkg A5Z3AxbclaSHb687oKYNNZVyWD3E9FZPBnm9dxTlyLySG381cDQL2VzfhDG38E4ETP UXLoi3ZznViBdTYmnzb+nEOD5g/rN93allpgkDrQ= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Will Deacon , James Morse , Sasha Levin Subject: [PATCH 5.4 423/475] KVM: arm64: Check arm64_get_bp_hardening_data() didnt return NULL Date: Thu, 14 Apr 2022 15:13:28 +0200 Message-Id: <20220414110906.898197156@linuxfoundation.org> X-Mailer: git-send-email 2.35.2 In-Reply-To: <20220414110855.141582785@linuxfoundation.org> References: <20220414110855.141582785@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: James Morse Will reports that with CONFIG_EXPERT=y and CONFIG_HARDEN_BRANCH_PREDICTOR=n, the kernel dereferences a NULL pointer during boot: [ 2.384444] Internal error: Oops: 96000004 [#1] PREEMPT SMP [ 2.384461] pstate: 20400085 (nzCv daIf +PAN -UAO) [ 2.384472] pc : cpu_hyp_reinit+0x114/0x30c [ 2.384476] lr : cpu_hyp_reinit+0x80/0x30c [ 2.384529] Call trace: [ 2.384533] cpu_hyp_reinit+0x114/0x30c [ 2.384537] _kvm_arch_hardware_enable+0x30/0x54 [ 2.384541] flush_smp_call_function_queue+0xe4/0x154 [ 2.384544] generic_smp_call_function_single_interrupt+0x10/0x18 [ 2.384549] ipi_handler+0x170/0x2b0 [ 2.384555] handle_percpu_devid_fasteoi_ipi+0x120/0x1cc [ 2.384560] __handle_domain_irq+0x9c/0xf4 [ 2.384563] gic_handle_irq+0x6c/0xe4 [ 2.384566] el1_irq+0xf0/0x1c0 [ 2.384570] arch_cpu_idle+0x28/0x44 [ 2.384574] do_idle+0x100/0x2a8 [ 2.384577] cpu_startup_entry+0x20/0x24 [ 2.384581] secondary_start_kernel+0x1b0/0x1cc [ 2.384589] Code: b9469d08 7100011f 540003ad 52800208 (f9400108) [ 2.384600] ---[ end trace 266d08dbf96ff143 ]--- [ 2.385171] Kernel panic - not syncing: Fatal exception in interrupt In this configuration arm64_get_bp_hardening_data() returns NULL. Add a check in kvm_get_hyp_vector(). Cc: Will Deacon Link: https://lore.kernel.org/linux-arm-kernel/20220408120041.GB27685@willie-the-truck/ Fixes: 26129ea2953b ("KVM: arm64: Add templates for BHB mitigation sequences") Cc: stable@vger.kernel.org # 5.4.x Signed-off-by: James Morse Signed-off-by: Sasha Levin --- arch/arm64/include/asm/kvm_mmu.h | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/arch/arm64/include/asm/kvm_mmu.h b/arch/arm64/include/asm/kvm_mmu.h index 78d110667c0c..ffe0aad96b17 100644 --- a/arch/arm64/include/asm/kvm_mmu.h +++ b/arch/arm64/include/asm/kvm_mmu.h @@ -479,7 +479,8 @@ static inline void *kvm_get_hyp_vector(void) int slot = -1; if ((cpus_have_const_cap(ARM64_HARDEN_BRANCH_PREDICTOR) || - cpus_have_const_cap(ARM64_SPECTRE_BHB)) && data->template_start) { + cpus_have_const_cap(ARM64_SPECTRE_BHB)) && + data && data->template_start) { vect = kern_hyp_va(kvm_ksym_ref(__bp_harden_hyp_vecs_start)); slot = data->hyp_vectors_slot; }