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=-9.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,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 E792BC10F0E for ; Sat, 13 Apr 2019 02:55:45 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B24242083E for ; Sat, 13 Apr 2019 02:55:45 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726981AbfDMCzo (ORCPT ); Fri, 12 Apr 2019 22:55:44 -0400 Received: from mga03.intel.com ([134.134.136.65]:28856 "EHLO mga03.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726925AbfDMCzn (ORCPT ); Fri, 12 Apr 2019 22:55:43 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga005.fm.intel.com ([10.253.24.32]) by orsmga103.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 12 Apr 2019 19:55:43 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.60,343,1549958400"; d="scan'208";a="336980521" Received: from sjchrist-coffee.jf.intel.com ([10.54.74.181]) by fmsmga005.fm.intel.com with ESMTP; 12 Apr 2019 19:55:42 -0700 From: Sean Christopherson To: Paolo Bonzini , =?UTF-8?q?Radim=20Kr=C4=8Dm=C3=A1=C5=99?= Cc: kvm@vger.kernel.org, Sean Christopherson Subject: [PATCH] KVM: x86/mmu: Fix an inverted list_empty() check when zapping sptes Date: Fri, 12 Apr 2019 19:55:41 -0700 Message-Id: <20190413025541.20303-1-sean.j.christopherson@intel.com> X-Mailer: git-send-email 2.21.0 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org A recently introduced helper for handling zap vs. remote flush incorrectly bails early, effectively leaking defunct shadow pages. Manifests as a slab BUG when exiting KVM due to the shadow pages being alive when their associated cache is destroyed. ========================================================================== BUG kvm_mmu_page_header: Objects remaining in kvm_mmu_page_header on ... -------------------------------------------------------------------------- Disabling lock debugging due to kernel taint INFO: Slab 0x00000000fc436387 objects=26 used=23 fp=0x00000000d023caee ... CPU: 6 PID: 4315 Comm: rmmod Tainted: G B 5.1.0-rc2+ #19 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015 Call Trace: dump_stack+0x46/0x5b slab_err+0xad/0xd0 ? on_each_cpu_mask+0x3c/0x50 ? ksm_migrate_page+0x60/0x60 ? on_each_cpu_cond_mask+0x7c/0xa0 ? __kmalloc+0x1ca/0x1e0 __kmem_cache_shutdown+0x13a/0x310 shutdown_cache+0xf/0x130 kmem_cache_destroy+0x1d5/0x200 kvm_mmu_module_exit+0xa/0x30 [kvm] kvm_arch_exit+0x45/0x60 [kvm] kvm_exit+0x6f/0x80 [kvm] vmx_exit+0x1a/0x50 [kvm_intel] __x64_sys_delete_module+0x153/0x1f0 ? exit_to_usermode_loop+0x88/0xc0 do_syscall_64+0x4f/0x100 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Fixes: a21136345cb6f ("KVM: x86/mmu: Split remote_flush+zap case out of kvm_mmu_flush_or_zap()") Cc: stable@vger.kernel.org Signed-off-by: Sean Christopherson --- arch/x86/kvm/mmu.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c index bd0727019674..e10962dfc203 100644 --- a/arch/x86/kvm/mmu.c +++ b/arch/x86/kvm/mmu.c @@ -2238,7 +2238,7 @@ static bool kvm_mmu_remote_flush_or_zap(struct kvm *kvm, struct list_head *invalid_list, bool remote_flush) { - if (!remote_flush && !list_empty(invalid_list)) + if (!remote_flush && list_empty(invalid_list)) return false; if (!list_empty(invalid_list)) -- 2.21.0