Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932464AbbLGPxd (ORCPT ); Mon, 7 Dec 2015 10:53:33 -0500 Received: from mail.linuxfoundation.org ([140.211.169.12]:59666 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933409AbbLGO7P (ORCPT ); Mon, 7 Dec 2015 09:59:15 -0500 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Dominik Dingel , David Hildenbrand , Christian Borntraeger Subject: [PATCH 4.2 093/124] KVM: s390: avoid memory overwrites on emergency signal injection Date: Mon, 7 Dec 2015 09:56:23 -0500 Message-Id: <20151207144924.297039947@linuxfoundation.org> X-Mailer: git-send-email 2.6.3 In-Reply-To: <20151207144919.656035367@linuxfoundation.org> References: <20151207144919.656035367@linuxfoundation.org> User-Agent: quilt/0.64 MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-15 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1589 Lines: 44 4.2-stable review patch. If anyone has any objections, please let me know. ------------------ From: David Hildenbrand commit b85de33a1a3433487b6a721cfdce25ec8673e622 upstream. Commit 383d0b050106 ("KVM: s390: handle pending local interrupts via bitmap") introduced a possible memory overwrite from user space. User space could pass an invalid emergency signal code (sending VCPU) and therefore exceed the bitmap. Let's take care of this case and check that the id is in the valid range. Reviewed-by: Dominik Dingel Signed-off-by: David Hildenbrand Signed-off-by: Christian Borntraeger Signed-off-by: Greg Kroah-Hartman --- arch/s390/kvm/interrupt.c | 4 ++++ 1 file changed, 4 insertions(+) --- a/arch/s390/kvm/interrupt.c +++ b/arch/s390/kvm/interrupt.c @@ -1130,6 +1130,10 @@ static int __inject_sigp_emergency(struc trace_kvm_s390_inject_vcpu(vcpu->vcpu_id, KVM_S390_INT_EMERGENCY, irq->u.emerg.code, 0, 2); + /* sending vcpu invalid */ + if (kvm_get_vcpu_by_id(vcpu->kvm, irq->u.emerg.code) == NULL) + return -EINVAL; + set_bit(irq->u.emerg.code, li->sigp_emerg_pending); set_bit(IRQ_PEND_EXT_EMERGENCY, &li->pending_irqs); atomic_set_mask(CPUSTAT_EXT_INT, li->cpuflags); -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/