From patchwork Tue Sep 29 10:59:27 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg Kroah-Hartman X-Patchwork-Id: 291122 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=-13.5 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, SIGNED_OFF_BY, 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 BF4C1C4727C for ; Tue, 29 Sep 2020 11:40:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7DD7B221E8 for ; Tue, 29 Sep 2020 11:40:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1601379606; bh=h0sytWbdEGOEgVs+icjGQEMOPOER/gMbDxTDVREQRBI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=1hYCfwKKzMREogdwWrLNBffuYW7Lj6UdkiMN7wBawHT4uOTk8aXyLKVkmy7xdxMIy 6QioyUJbJvYZkUpLib/ZlTqzcibZx28hVPBlYi+9xAcj2738mUG3XiVAkanNlht8ze LHulpq/t5zEv23R9Z+ep0IEb+iypV/VSbf8ySatQ= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729892AbgI2LkF (ORCPT ); Tue, 29 Sep 2020 07:40:05 -0400 Received: from mail.kernel.org ([198.145.29.99]:35262 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730519AbgI2LkC (ORCPT ); Tue, 29 Sep 2020 07:40:02 -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 71726206E5; Tue, 29 Sep 2020 11:40:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1601379601; bh=h0sytWbdEGOEgVs+icjGQEMOPOER/gMbDxTDVREQRBI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=NVUX6mGh/kiTmMEanLpZJP7yqoXmJfUd/S6pHxWC2Z3GoIhBXeyjz18aPDF6qkI11 9eBK5WpKxR8FCImd5WHHyIvSrluuzBEsUGPvdnoH8xowH2FfhPwWECnrd9+XFX/qh0 Ofxpt9zZlGySlLjeTmsYTu9GEmb6g8vXeT6L9mTQ= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, James Morse , Zenghui Yu , Marc Zyngier , Sasha Levin Subject: [PATCH 5.4 236/388] KVM: arm64: vgic-v3: Retire all pending LPIs on vcpu destroy Date: Tue, 29 Sep 2020 12:59:27 +0200 Message-Id: <20200929110021.904289673@linuxfoundation.org> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20200929110010.467764689@linuxfoundation.org> References: <20200929110010.467764689@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Zenghui Yu [ Upstream commit 969ce8b5260d8ec01e6f1949d2927a86419663ce ] It's likely that the vcpu fails to handle all virtual interrupts if userspace decides to destroy it, leaving the pending ones stay in the ap_list. If the un-handled one is a LPI, its vgic_irq structure will be eventually leaked because of an extra refcount increment in vgic_queue_irq_unlock(). This was detected by kmemleak on almost every guest destroy, the backtrace is as follows: unreferenced object 0xffff80725aed5500 (size 128): comm "CPU 5/KVM", pid 40711, jiffies 4298024754 (age 166366.512s) hex dump (first 32 bytes): 00 00 00 00 00 00 00 00 08 01 a9 73 6d 80 ff ff ...........sm... c8 61 ee a9 00 20 ff ff 28 1e 55 81 6c 80 ff ff .a... ..(.U.l... backtrace: [<000000004bcaa122>] kmem_cache_alloc_trace+0x2dc/0x418 [<0000000069c7dabb>] vgic_add_lpi+0x88/0x418 [<00000000bfefd5c5>] vgic_its_cmd_handle_mapi+0x4dc/0x588 [<00000000cf993975>] vgic_its_process_commands.part.5+0x484/0x1198 [<000000004bd3f8e3>] vgic_its_process_commands+0x50/0x80 [<00000000b9a65b2b>] vgic_mmio_write_its_cwriter+0xac/0x108 [<0000000009641ebb>] dispatch_mmio_write+0xd0/0x188 [<000000008f79d288>] __kvm_io_bus_write+0x134/0x240 [<00000000882f39ac>] kvm_io_bus_write+0xe0/0x150 [<0000000078197602>] io_mem_abort+0x484/0x7b8 [<0000000060954e3c>] kvm_handle_guest_abort+0x4cc/0xa58 [<00000000e0d0cd65>] handle_exit+0x24c/0x770 [<00000000b44a7fad>] kvm_arch_vcpu_ioctl_run+0x460/0x1988 [<0000000025fb897c>] kvm_vcpu_ioctl+0x4f8/0xee0 [<000000003271e317>] do_vfs_ioctl+0x160/0xcd8 [<00000000e7f39607>] ksys_ioctl+0x98/0xd8 Fix it by retiring all pending LPIs in the ap_list on the destroy path. p.s. I can also reproduce it on a normal guest shutdown. It is because userspace still send LPIs to vcpu (through KVM_SIGNAL_MSI ioctl) while the guest is being shutdown and unable to handle it. A little strange though and haven't dig further... Reviewed-by: James Morse Signed-off-by: Zenghui Yu [maz: moved the distributor deallocation down to avoid an UAF splat] Signed-off-by: Marc Zyngier Link: https://lore.kernel.org/r/20200414030349.625-2-yuzenghui@huawei.com Signed-off-by: Sasha Levin --- virt/kvm/arm/vgic/vgic-init.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) diff --git a/virt/kvm/arm/vgic/vgic-init.c b/virt/kvm/arm/vgic/vgic-init.c index 6d85c6d894c39..6899101538890 100644 --- a/virt/kvm/arm/vgic/vgic-init.c +++ b/virt/kvm/arm/vgic/vgic-init.c @@ -358,6 +358,12 @@ void kvm_vgic_vcpu_destroy(struct kvm_vcpu *vcpu) { struct vgic_cpu *vgic_cpu = &vcpu->arch.vgic_cpu; + /* + * Retire all pending LPIs on this vcpu anyway as we're + * going to destroy it. + */ + vgic_flush_pending_lpis(vcpu); + INIT_LIST_HEAD(&vgic_cpu->ap_list_head); } @@ -369,10 +375,10 @@ static void __kvm_vgic_destroy(struct kvm *kvm) vgic_debug_destroy(kvm); - kvm_vgic_dist_destroy(kvm); - kvm_for_each_vcpu(i, vcpu, kvm) kvm_vgic_vcpu_destroy(vcpu); + + kvm_vgic_dist_destroy(kvm); } void kvm_vgic_destroy(struct kvm *kvm)