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=-19.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT autolearn=unavailable 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 4EC25C433ED for ; Thu, 20 May 2021 11:45:28 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 30E536105A for ; Thu, 20 May 2021 11:45:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S242408AbhETLqn (ORCPT ); Thu, 20 May 2021 07:46:43 -0400 Received: from mail.kernel.org ([198.145.29.99]:43606 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S240404AbhETLWg (ORCPT ); Thu, 20 May 2021 07:22:36 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 8E9296143B; Thu, 20 May 2021 10:11:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1621505514; bh=0TobhOhGqIN3KUTQo324aLsaE1xxpO7oxPxdAzznYN0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=sUXU55Gf7uc81RiGUqq8AiKKXKfOhaOWTaLiTEW4aUAc3n+15692oPuYxKeNijXrv gaGYzEB433qURX9mlIeKLBnZNeNF7Bwj9Ew6T7YDyA4CRnwAc/obuNfPltQ2sMlHm3 sKsoDY+kSPjYYUUW4mSNPUIdlIt7cCTf+swyF4QI= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Thomas Gleixner , Paolo Bonzini Subject: [PATCH 4.4 169/190] KVM: x86: Cancel pvclock_gtod_work on module removal Date: Thu, 20 May 2021 11:23:53 +0200 Message-Id: <20210520092107.764024315@linuxfoundation.org> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20210520092102.149300807@linuxfoundation.org> References: <20210520092102.149300807@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Thomas Gleixner commit 594b27e677b35f9734b1969d175ebc6146741109 upstream. Nothing prevents the following: pvclock_gtod_notify() queue_work(system_long_wq, &pvclock_gtod_work); ... remove_module(kvm); ... work_queue_run() pvclock_gtod_work() <- UAF Ditto for any other operation on that workqueue list head which touches pvclock_gtod_work after module removal. Cancel the work in kvm_arch_exit() to prevent that. Fixes: 16e8d74d2da9 ("KVM: x86: notifier for clocksource changes") Signed-off-by: Thomas Gleixner Message-Id: <87czu4onry.ffs@nanos.tec.linutronix.de> Cc: stable@vger.kernel.org Signed-off-by: Paolo Bonzini Signed-off-by: Greg Kroah-Hartman --- arch/x86/kvm/x86.c | 1 + 1 file changed, 1 insertion(+) --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -6016,6 +6016,7 @@ void kvm_arch_exit(void) unregister_hotcpu_notifier(&kvmclock_cpu_notifier_block); #ifdef CONFIG_X86_64 pvclock_gtod_unregister_notifier(&pvclock_gtod_notifier); + cancel_work_sync(&pvclock_gtod_work); #endif kvm_x86_ops = NULL; kvm_mmu_module_exit();