From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755918AbbHYP3M (ORCPT ); Tue, 25 Aug 2015 11:29:12 -0400 Received: from smtprelay0045.hostedemail.com ([216.40.44.45]:35897 "EHLO smtprelay.hostedemail.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1753021AbbHYP3K (ORCPT ); Tue, 25 Aug 2015 11:29:10 -0400 X-Session-Marker: 6A6F6540706572636865732E636F6D X-Spam-Summary: 2,0,0,,d41d8cd98f00b204,joe@perches.com,:::::::::::::,RULES_HIT:41:355:379:541:599:973:988:989:1260:1277:1311:1313:1314:1345:1359:1373:1437:1515:1516:1518:1534:1541:1593:1594:1711:1730:1747:1777:1792:2393:2553:2559:2562:2828:3138:3139:3140:3141:3142:3352:3622:3866:3867:3868:3870:3871:4321:5007:6119:6261:7903:10004:10400:10848:11026:11232:11473:11658:11914:12043:12296:12438:12517:12519:12740:13019:13069:13255:13311:13357:13972:14096:14097:21080,0,RBL:none,CacheIP:none,Bayesian:0.5,0.5,0.5,Netcheck:none,DomainCache:0,MSF:not bulk,SPF:fn,MSBL:0,DNSBL:none,Custom_rules:0:0:0 X-HE-Tag: shop88_4fb2628315f5b X-Filterd-Recvd-Size: 2107 Message-ID: <1440516546.2670.88.camel@perches.com> Subject: Re: [PATCH V2 1/3] kvm: use kmalloc() instead of kzalloc() during iodev register/unregister From: Joe Perches To: Jason Wang Cc: gleb@kernel.org, pbonzini@redhat.com, kvm@vger.kernel.org, linux-kernel@vger.kernel.org, cornelia.huck@de.ibm.com, "Michael S. Tsirkin" Date: Tue, 25 Aug 2015 08:29:06 -0700 In-Reply-To: <1440488835-4388-1-git-send-email-jasowang@redhat.com> References: <1440488835-4388-1-git-send-email-jasowang@redhat.com> Content-Type: text/plain; charset="ISO-8859-1" X-Mailer: Evolution 3.12.11-0ubuntu3 Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 2015-08-25 at 15:47 +0800, Jason Wang wrote: > All fields of kvm_io_range were initialized or copied explicitly > afterwards. So switch to use kmalloc(). Is there any compiler added alignment padding in either structure? If so, those padding areas would now be uninitialized and may leak kernel data if copied to user-space. > diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c [] > @@ -3248,7 +3248,7 @@ int kvm_io_bus_register_dev(struct kvm *kvm, enum kvm_bus bus_idx, gpa_t addr, > if (bus->dev_count - bus->ioeventfd_count > NR_IOBUS_DEVS - 1) > return -ENOSPC; > > - new_bus = kzalloc(sizeof(*bus) + ((bus->dev_count + 1) * > + new_bus = kmalloc(sizeof(*bus) + ((bus->dev_count + 1) * > sizeof(struct kvm_io_range)), GFP_KERNEL); > if (!new_bus) > return -ENOMEM; > @@ -3280,7 +3280,7 @@ int kvm_io_bus_unregister_dev(struct kvm *kvm, enum kvm_bus bus_idx, > if (r) > return r; > > - new_bus = kzalloc(sizeof(*bus) + ((bus->dev_count - 1) * > + new_bus = kmalloc(sizeof(*bus) + ((bus->dev_count - 1) * > sizeof(struct kvm_io_range)), GFP_KERNEL); > if (!new_bus) > return -ENOMEM;