From patchwork Tue Sep 29 10:59:06 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg Kroah-Hartman X-Patchwork-Id: 263386 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=-13.5 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, SIGNED_OFF_BY, SPF_HELO_NONE, SPF_PASS, URIBL_BLOCKED, USER_AGENT_GIT autolearn=ham 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 6EF28C47423 for ; Tue, 29 Sep 2020 11:07:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 225D122204 for ; Tue, 29 Sep 2020 11:07:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1601377654; bh=tSx6nNkkj72nzkCz4hDeAGHMhtGpVKtr9FMBzPm5iaM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=y0tmCP9XAR0cR17vy7kP8SgLZCQPB3e91BS39A8zGXIzpsK58d0LPetaJYh5tawje um+SEruT4jOkWC6fbeGrzgUugC9+wWa8V3P6u/eFqLau5s/EV75Blk6fuHjZiiYrio 4Is6Z/hfrqgrREMQaX0raAprppAQnotSqZYQdbXs= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728590AbgI2LHd (ORCPT ); Tue, 29 Sep 2020 07:07:33 -0400 Received: from mail.kernel.org ([198.145.29.99]:45726 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728866AbgI2LHO (ORCPT ); Tue, 29 Sep 2020 07:07:14 -0400 Received: from localhost (83-86-74-64.cable.dynamic.v4.ziggo.nl [83.86.74.64]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 7CA6A21D46; Tue, 29 Sep 2020 11:07:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1601377633; bh=tSx6nNkkj72nzkCz4hDeAGHMhtGpVKtr9FMBzPm5iaM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=VWFq8HiaFYGk+I8YycZ41wyA2Cz8qIy4ABtS+IrNjrKv1asjO+tYOf9enLnPTQDUD edusUjVs1SkC0s+kH8AueFFYqJb8L2mCfH0+9obJ9TV7qqlYdFWxNN93aILFcnV0HO PI+NL5ul+KSWFqxXvo8XKvBQL5+v1w1xlxfE6p0c= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Rustam Kovhaev , Vitaly Kuznetsov , Paolo Bonzini , Sasha Levin , syzbot+f196caa45793d6374707@syzkaller.appspotmail.com Subject: [PATCH 4.9 002/121] KVM: fix memory leak in kvm_io_bus_unregister_dev() Date: Tue, 29 Sep 2020 12:59:06 +0200 Message-Id: <20200929105930.303978981@linuxfoundation.org> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20200929105930.172747117@linuxfoundation.org> References: <20200929105930.172747117@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Rustam Kovhaev [ Upstream commit f65886606c2d3b562716de030706dfe1bea4ed5e ] 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 Message-Id: <20200907185535.233114-1-rkovhaev@gmail.com> Signed-off-by: Paolo Bonzini Signed-off-by: Sasha Levin --- 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 4e4bb5dd2dcd5..010d8aee9346b 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -3639,7 +3639,7 @@ 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->buses[bus_idx]; @@ -3656,17 +3656,20 @@ void kvm_io_bus_unregister_dev(struct kvm *kvm, enum kvm_bus bus_idx, new_bus = kmalloc(sizeof(*bus) + ((bus->dev_count - 1) * sizeof(struct kvm_io_range)), GFP_KERNEL); - 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);