Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758967AbcCVKpG (ORCPT ); Tue, 22 Mar 2016 06:45:06 -0400 Received: from youngberry.canonical.com ([91.189.89.112]:56835 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932519AbcCVKmu (ORCPT ); Tue, 22 Mar 2016 06:42:50 -0400 From: Luis Henriques To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Cc: "Michael S. Tsirkin" , Marc Zyngier , Luis Henriques Subject: [PATCH 3.16.y-ckt 093/142] arm/arm64: KVM: Fix ioctl error handling Date: Tue, 22 Mar 2016 10:40:22 +0000 Message-Id: <1458643271-4227-94-git-send-email-luis.henriques@canonical.com> In-Reply-To: <1458643271-4227-1-git-send-email-luis.henriques@canonical.com> References: <1458643271-4227-1-git-send-email-luis.henriques@canonical.com> X-Extended-Stable: 3.16 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1361 Lines: 41 3.16.7-ckt26 -stable review patch. If anyone has any objections, please let me know. ---8<------------------------------------------------------------ From: "Michael S. Tsirkin" commit 4cad67fca3fc952d6f2ed9e799621f07666a560f upstream. Calling return copy_to_user(...) in an ioctl will not do the right thing if there's a pagefault: copy_to_user returns the number of bytes not copied in this case. Fix up kvm to do return copy_to_user(...)) ? -EFAULT : 0; everywhere. Acked-by: Christoffer Dall Signed-off-by: Michael S. Tsirkin Signed-off-by: Marc Zyngier [ luis: backported to 3.16: - dropped changes to arch/arm64/kvm/guest.c ] Signed-off-by: Luis Henriques --- arch/arm/kvm/guest.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/arm/kvm/guest.c b/arch/arm/kvm/guest.c index 2786eae10c0d..f3f6415b7828 100644 --- a/arch/arm/kvm/guest.c +++ b/arch/arm/kvm/guest.c @@ -183,7 +183,7 @@ static int get_timer_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg) u64 val; val = kvm_arm_timer_get_reg(vcpu, reg->id); - return copy_to_user(uaddr, &val, KVM_REG_SIZE(reg->id)); + return copy_to_user(uaddr, &val, KVM_REG_SIZE(reg->id)) ? -EFAULT : 0; } static unsigned long num_core_regs(void)