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=-18.7 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_GIT 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 9822EC71156 for ; Tue, 1 Dec 2020 09:26:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 41E7E2067D for ; Tue, 1 Dec 2020 09:26:56 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="c3WVnpxX" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2390991AbgLAJ0b (ORCPT ); Tue, 1 Dec 2020 04:26:31 -0500 Received: from mail.kernel.org ([198.145.29.99]:40430 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2388045AbgLAJDY (ORCPT ); Tue, 1 Dec 2020 04:03:24 -0500 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 2446C22245; Tue, 1 Dec 2020 09:02:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1606813362; bh=RZ0Yuo35xupoAMfjsdzGM6d++OSlTTNTmyuaKUyK40A=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=c3WVnpxXaPkEhIwpVjiXdxbZsBqhzJ/Q4C/HmbQKyy3h4DXwFQNdV8+PVRlCNeic6 a+JJEwyLu3kM7zUFjFooz69GubFAMHbY+yUKv3z4LW2m+vCWBVnmY9ENIkV3McmOGW rIuwyBFCkn6RGDcUFxQCVMLUETS5YBaLVlbS6//k= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Greg Kurz , =?UTF-8?q?C=C3=A9dric=20Le=20Goater?= , Michael Ellerman Subject: [PATCH 5.4 14/98] KVM: PPC: Book3S HV: XIVE: Fix possible oops when accessing ESB page Date: Tue, 1 Dec 2020 09:52:51 +0100 Message-Id: <20201201084654.618075442@linuxfoundation.org> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20201201084652.827177826@linuxfoundation.org> References: <20201201084652.827177826@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Cédric Le Goater commit 75b49620267c700f0a07fec7f27f69852db70e46 upstream. When accessing the ESB page of a source interrupt, the fault handler will retrieve the page address from the XIVE interrupt 'xive_irq_data' structure. If the associated KVM XIVE interrupt is not valid, that is not allocated at the HW level for some reason, the fault handler will dereference a NULL pointer leading to the oops below : WARNING: CPU: 40 PID: 59101 at arch/powerpc/kvm/book3s_xive_native.c:259 xive_native_esb_fault+0xe4/0x240 [kvm] CPU: 40 PID: 59101 Comm: qemu-system-ppc Kdump: loaded Tainted: G W --------- - - 4.18.0-240.el8.ppc64le #1 NIP: c00800000e949fac LR: c00000000044b164 CTR: c00800000e949ec8 REGS: c000001f69617840 TRAP: 0700 Tainted: G W --------- - - (4.18.0-240.el8.ppc64le) MSR: 9000000000029033 CR: 44044282 XER: 00000000 CFAR: c00000000044b160 IRQMASK: 0 GPR00: c00000000044b164 c000001f69617ac0 c00800000e96e000 c000001f69617c10 GPR04: 05faa2b21e000080 0000000000000000 0000000000000005 ffffffffffffffff GPR08: 0000000000000000 0000000000000001 0000000000000000 0000000000000001 GPR12: c00800000e949ec8 c000001ffffd3400 0000000000000000 0000000000000000 GPR16: 0000000000000000 0000000000000000 0000000000000000 0000000000000000 GPR20: 0000000000000000 0000000000000000 c000001f5c065160 c000000001c76f90 GPR24: c000001f06f20000 c000001f5c065100 0000000000000008 c000001f0eb98c78 GPR28: c000001dcab40000 c000001dcab403d8 c000001f69617c10 0000000000000011 NIP [c00800000e949fac] xive_native_esb_fault+0xe4/0x240 [kvm] LR [c00000000044b164] __do_fault+0x64/0x220 Call Trace: [c000001f69617ac0] [0000000137a5dc20] 0x137a5dc20 (unreliable) [c000001f69617b50] [c00000000044b164] __do_fault+0x64/0x220 [c000001f69617b90] [c000000000453838] do_fault+0x218/0x930 [c000001f69617bf0] [c000000000456f50] __handle_mm_fault+0x350/0xdf0 [c000001f69617cd0] [c000000000457b1c] handle_mm_fault+0x12c/0x310 [c000001f69617d10] [c00000000007ef44] __do_page_fault+0x264/0xbb0 [c000001f69617df0] [c00000000007f8c8] do_page_fault+0x38/0xd0 [c000001f69617e30] [c00000000000a714] handle_page_fault+0x18/0x38 Instruction dump: 40c2fff0 7c2004ac 2fa90000 409e0118 73e90001 41820080 e8bd0008 7c2004ac 7ca90074 39400000 915c0000 7929d182 <0b090000> 2fa50000 419e0080 e89e0018 ---[ end trace 66c6ff034c53f64f ]--- xive-kvm: xive_native_esb_fault: accessing invalid ESB page for source 8 ! Fix that by checking the validity of the KVM XIVE interrupt structure. Fixes: 6520ca64cde7 ("KVM: PPC: Book3S HV: XIVE: Add a mapping for the source ESB pages") Cc: stable@vger.kernel.org # v5.2+ Reported-by: Greg Kurz Signed-off-by: Cédric Le Goater Tested-by: Greg Kurz Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20201105134713.656160-1-clg@kaod.org Signed-off-by: Greg Kroah-Hartman --- arch/powerpc/kvm/book3s_xive_native.c | 7 +++++++ 1 file changed, 7 insertions(+) --- a/arch/powerpc/kvm/book3s_xive_native.c +++ b/arch/powerpc/kvm/book3s_xive_native.c @@ -252,6 +252,13 @@ static vm_fault_t xive_native_esb_fault( } state = &sb->irq_state[src]; + + /* Some sanity checking */ + if (!state->valid) { + pr_devel("%s: source %lx invalid !\n", __func__, irq); + return VM_FAULT_SIGBUS; + } + kvmppc_xive_select_irq(state, &hw_num, &xd); arch_spin_lock(&sb->lock);