Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753014AbcKYIbl (ORCPT ); Fri, 25 Nov 2016 03:31:41 -0500 Received: from mx2.suse.de ([195.135.220.15]:45258 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752096AbcKYIa5 (ORCPT ); Fri, 25 Nov 2016 03:30:57 -0500 X-Amavis-Alert: BAD HEADER SECTION, Duplicate header field: "References" From: Jiri Slaby To: stable@vger.kernel.org Cc: linux-kernel@vger.kernel.org, Ido Yariv , =?UTF-8?q?Radim=20Kr=C4=8Dm=C3=A1=C5=99?= , Jiri Slaby Subject: [PATCH 3.12 027/127] KVM: x86: fix wbinvd_dirty_mask use-after-free Date: Fri, 25 Nov 2016 09:29:00 +0100 Message-Id: <5a0561dff3f260364619f999693a5d305bf0e831.1480062521.git.jslaby@suse.cz> X-Mailer: git-send-email 2.10.2 In-Reply-To: References: In-Reply-To: References: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1341 Lines: 48 From: Ido Yariv 3.12-stable review patch. If anyone has any objections, please let me know. =============== commit bd768e146624cbec7122ed15dead8daa137d909d upstream. vcpu->arch.wbinvd_dirty_mask may still be used after freeing it, corrupting memory. For example, the following call trace may set a bit in an already freed cpu mask: kvm_arch_vcpu_load vcpu_load vmx_free_vcpu_nested vmx_free_vcpu kvm_arch_vcpu_free Fix this by deferring freeing of wbinvd_dirty_mask. Signed-off-by: Ido Yariv Reviewed-by: Paolo Bonzini Signed-off-by: Radim Krčmář Signed-off-by: Jiri Slaby --- arch/x86/kvm/x86.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 06b37a671b12..c9e086117ae2 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -6662,11 +6662,13 @@ void kvm_put_guest_fpu(struct kvm_vcpu *vcpu) void kvm_arch_vcpu_free(struct kvm_vcpu *vcpu) { + void *wbinvd_dirty_mask = vcpu->arch.wbinvd_dirty_mask; + kvmclock_reset(vcpu); - free_cpumask_var(vcpu->arch.wbinvd_dirty_mask); fx_free(vcpu); kvm_x86_ops->vcpu_free(vcpu); + free_cpumask_var(wbinvd_dirty_mask); } struct kvm_vcpu *kvm_arch_vcpu_create(struct kvm *kvm, -- 2.10.2