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=-13.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,NICE_REPLY_A,SIGNED_OFF_BY,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 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 28D3BC43461 for ; Fri, 11 Sep 2020 16:05:09 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E2CF1221EF for ; Fri, 11 Sep 2020 16:05:08 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="Jxkz3ZnP" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726585AbgIKQEi (ORCPT ); Fri, 11 Sep 2020 12:04:38 -0400 Received: from us-smtp-2.mimecast.com ([205.139.110.61]:20819 "EHLO us-smtp-delivery-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726170AbgIKQCa (ORCPT ); Fri, 11 Sep 2020 12:02:30 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1599840149; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=UzNqZBAGXS7F5Dy3gzRVUTnuTyaskfH6gaEmCpanmiQ=; b=Jxkz3ZnPHY2UltA5/0IG6sFLpGKl0UYLzXxJgFKEzwHnBqQvoQLGy7enNRFQoHupoxbA0J 2qoyQTepefWaYmqjOT6kdasjKyOq6zeifEg5ZoDMwmfSdR7HA2n9vWWRjjl7CYThELzahi fzVUuWtq/rTrV2+1MHCrRNYIKj6dcvo= Received: from mail-wm1-f71.google.com (mail-wm1-f71.google.com [209.85.128.71]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-434-rixSgNOXOwmXf9JTWND1tg-1; Fri, 11 Sep 2020 12:02:25 -0400 X-MC-Unique: rixSgNOXOwmXf9JTWND1tg-1 Received: by mail-wm1-f71.google.com with SMTP id k12so2018664wmj.1 for ; Fri, 11 Sep 2020 09:02:24 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=UzNqZBAGXS7F5Dy3gzRVUTnuTyaskfH6gaEmCpanmiQ=; b=S4otxuLgNJ1GRi9Zi8a0jtPtNbWbJF+byTvTe71cB7RPi8neD0WMNDU48V0LgsurEu 3B5EwnSraQ1inSLXuyigbIN17ulDfTUw9Y+7PUbOWyZXtAmYrSrPA6ge4gNrcxSKlhNA ICa7d2UIkqf0NuHYGApYIbvcm0SaOBVlNcz08YbjxpdA2Hp0KxFZiZTP62uBPgA7XhJx 0NgfEeqpEzypTTpsRZleDQCYSYlWdAAhtk99ll9BXwp8EMOZ54n9o7KgEIR9eHWU9M85 K3ByUa/LhvcPcO0CYp5cyiJYSV3HSa/MMqtI52CnRN+Bl7jRr9RWyGOpsuOKttco/KJY cnkA== X-Gm-Message-State: AOAM530ewwSLuqhl2SZwPzWxM1BCTB9jnwozMi3ZrfZk3TuKibEzG5Yn kzOXU2oCf8AgignaKlPE9RCoOkSOEoxPF79kjTUoHlUT8FFDfLcmEHwXiAXY3Bk6o3YLESxj9Ja mviflUFHvvqQP2OZnDyZBKe6E X-Received: by 2002:adf:f70d:: with SMTP id r13mr2807365wrp.317.1599840143600; Fri, 11 Sep 2020 09:02:23 -0700 (PDT) X-Google-Smtp-Source: ABdhPJzlZ/52RedjxDE7fk9zVT8weEe/dNfRBYU1gf7UxBbf9Eg9Ud+Y+MHJJZv6HKemXzFN9Gm3jw== X-Received: by 2002:adf:f70d:: with SMTP id r13mr2807329wrp.317.1599840143390; Fri, 11 Sep 2020 09:02:23 -0700 (PDT) Received: from [192.168.10.150] ([93.56.170.5]) by smtp.gmail.com with ESMTPSA id l10sm4868973wru.59.2020.09.11.09.02.22 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Fri, 11 Sep 2020 09:02:22 -0700 (PDT) Subject: Re: [RESEND PATCH v2] KVM: fix memory leak in kvm_io_bus_unregister_dev() To: Rustam Kovhaev , vkuznets@redhat.com, gustavoars@kernel.org, kvm@vger.kernel.org Cc: linux-kernel@vger.kernel.org, gregkh@linuxfoundation.org, stable@vger.kernel.org References: <20200907185535.233114-1-rkovhaev@gmail.com> From: Paolo Bonzini Message-ID: <979a4030-6934-41bd-ee55-a3e301f04cc6@redhat.com> Date: Fri, 11 Sep 2020 18:02:21 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.11.0 MIME-Version: 1.0 In-Reply-To: <20200907185535.233114-1-rkovhaev@gmail.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 07/09/20 20:55, Rustam Kovhaev wrote: > when kmalloc() fails in kvm_io_bus_unregister_dev(), before removing > the bus, we should iterate over all other devices linked to it and call > kvm_iodevice_destructor() for them > > Fixes: 90db10434b16 ("KVM: kvm_io_bus_unregister_dev() should never fail") > Cc: stable@vger.kernel.org > Reported-and-tested-by: syzbot+f196caa45793d6374707@syzkaller.appspotmail.com > Link: https://syzkaller.appspot.com/bug?extid=f196caa45793d6374707 > Signed-off-by: Rustam Kovhaev > Reviewed-by: Vitaly Kuznetsov > --- > v2: > - remove redundant whitespace > - remove goto statement and use if/else > - add Fixes tag > --- > virt/kvm/kvm_main.c | 21 ++++++++++++--------- > 1 file changed, 12 insertions(+), 9 deletions(-) > > diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c > index 67cd0b88a6b6..cf88233b819a 100644 > --- a/virt/kvm/kvm_main.c > +++ b/virt/kvm/kvm_main.c > @@ -4332,7 +4332,7 @@ int kvm_io_bus_register_dev(struct kvm *kvm, enum kvm_bus bus_idx, gpa_t addr, > void kvm_io_bus_unregister_dev(struct kvm *kvm, enum kvm_bus bus_idx, > struct kvm_io_device *dev) > { > - int i; > + int i, j; > struct kvm_io_bus *new_bus, *bus; > > bus = kvm_get_bus(kvm, bus_idx); > @@ -4349,17 +4349,20 @@ void kvm_io_bus_unregister_dev(struct kvm *kvm, enum kvm_bus bus_idx, > > new_bus = kmalloc(struct_size(bus, range, bus->dev_count - 1), > GFP_KERNEL_ACCOUNT); > - if (!new_bus) { > + if (new_bus) { > + memcpy(new_bus, bus, sizeof(*bus) + i * sizeof(struct kvm_io_range)); > + new_bus->dev_count--; > + memcpy(new_bus->range + i, bus->range + i + 1, > + (new_bus->dev_count - i) * sizeof(struct kvm_io_range)); > + } else { > pr_err("kvm: failed to shrink bus, removing it completely\n"); > - goto broken; > + for (j = 0; j < bus->dev_count; j++) { > + if (j == i) > + continue; > + kvm_iodevice_destructor(bus->range[j].dev); > + } > } > > - memcpy(new_bus, bus, sizeof(*bus) + i * sizeof(struct kvm_io_range)); > - new_bus->dev_count--; > - memcpy(new_bus->range + i, bus->range + i + 1, > - (new_bus->dev_count - i) * sizeof(struct kvm_io_range)); > - > -broken: > rcu_assign_pointer(kvm->buses[bus_idx], new_bus); > synchronize_srcu_expedited(&kvm->srcu); > kfree(bus); > Queued, thanks. I am currently on leave so I am going through the patches and queuing them, but I will only push kvm/next and kvm/queue next week. kvm/master patches will be sent to Linus for the next -rc though. Paolo