From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:47462 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755279AbcGYVlJ (ORCPT ); Mon, 25 Jul 2016 17:41:09 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, James Morse , Marc Zyngier , Christoffer Dall Subject: [PATCH 4.6 080/203] KVM: arm/arm64: Stop leaking vcpu pid references Date: Mon, 25 Jul 2016 13:54:55 -0700 Message-Id: <20160725203432.576960353@linuxfoundation.org> In-Reply-To: <20160725203429.221747288@linuxfoundation.org> References: <20160725203429.221747288@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: stable-owner@vger.kernel.org List-ID: 4.6-stable review patch. If anyone has any objections, please let me know. ------------------ From: James Morse commit 591d215afcc2f94e8e2c69a63c924c044677eb31 upstream. kvm provides kvm_vcpu_uninit(), which amongst other things, releases the last reference to the struct pid of the task that was last running the vcpu. On arm64 built with CONFIG_DEBUG_KMEMLEAK, starting a guest with kvmtool, then killing it with SIGKILL results (after some considerable time) in: > cat /sys/kernel/debug/kmemleak > unreferenced object 0xffff80007d5ea080 (size 128): > comm "lkvm", pid 2025, jiffies 4294942645 (age 1107.776s) > hex dump (first 32 bytes): > 01 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ > 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ > backtrace: > [] create_object+0xfc/0x278 > [] kmemleak_alloc+0x34/0x70 > [] kmem_cache_alloc+0x16c/0x1d8 > [] alloc_pid+0x34/0x4d0 > [] copy_process.isra.6+0x79c/0x1338 > [] _do_fork+0x74/0x320 > [] SyS_clone+0x18/0x20 > [] el0_svc_naked+0x24/0x28 > [] 0xffffffffffffffff On x86 kvm_vcpu_uninit() is called on the path from kvm_arch_destroy_vm(), on arm no equivalent call is made. Add the call to kvm_arch_vcpu_free(). Signed-off-by: James Morse Fixes: 749cf76c5a36 ("KVM: ARM: Initial skeleton to compile KVM support") Acked-by: Marc Zyngier Signed-off-by: Christoffer Dall Signed-off-by: Greg Kroah-Hartman --- arch/arm/kvm/arm.c | 1 + 1 file changed, 1 insertion(+) --- a/arch/arm/kvm/arm.c +++ b/arch/arm/kvm/arm.c @@ -267,6 +267,7 @@ void kvm_arch_vcpu_free(struct kvm_vcpu kvm_timer_vcpu_terminate(vcpu); kvm_vgic_vcpu_destroy(vcpu); kvm_pmu_vcpu_destroy(vcpu); + kvm_vcpu_uninit(vcpu); kmem_cache_free(kvm_vcpu_cache, vcpu); }