From patchwork Wed Nov 4 15:01:43 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Paolo Bonzini X-Patchwork-Id: 318640 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=-9.8 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, SIGNED_OFF_BY, SPF_HELO_NONE, SPF_PASS, URIBL_BLOCKED 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 7CF61C2D0A3 for ; Wed, 4 Nov 2020 15:11:58 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id DF5622074B for ; Wed, 4 Nov 2020 15:11:57 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="LtwmDZwR" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org DF5622074B Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:50996 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1kaKS4-0000T0-Ul for qemu-devel@archiver.kernel.org; Wed, 04 Nov 2020 10:11:56 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:55358) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1kaKIb-00034G-J0 for qemu-devel@nongnu.org; Wed, 04 Nov 2020 10:02:09 -0500 Received: from us-smtp-delivery-124.mimecast.com ([63.128.21.124]:53475) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.90_1) (envelope-from ) id 1kaKIW-00062Q-6Q for qemu-devel@nongnu.org; Wed, 04 Nov 2020 10:02:09 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1604502123; 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=xDGw8RS5yS0Ad+cF6EFO+debCWGbFVNQRHUBR33EE8U=; b=LtwmDZwRu3DJUbN3iwRu+b+dipoQAB2imRCHFzAdpb2bQ7DH4XMlnTZ7w5S6uTGPQtBc8U whOUDZugzX4vE2awzHS+65tDsUyHocNsEobfXD0obN1oeBEqNYbgjy2IQUt3ppgzRPviiA VrjNIrsMxyK/usTredcmi1GHEQvncrA= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-100-qh_U4VqkN5C6E6N3d9X95w-1; Wed, 04 Nov 2020 10:02:00 -0500 X-MC-Unique: qh_U4VqkN5C6E6N3d9X95w-1 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id C5B541016CE8; Wed, 4 Nov 2020 15:01:59 +0000 (UTC) Received: from virtlab701.virt.lab.eng.bos.redhat.com (virtlab701.virt.lab.eng.bos.redhat.com [10.19.152.228]) by smtp.corp.redhat.com (Postfix) with ESMTP id 771E06EF6A; Wed, 4 Nov 2020 15:01:59 +0000 (UTC) From: Paolo Bonzini To: qemu-devel@nongnu.org Subject: [PULL 10/20] tests/qtest/libqos/ahci.c: Avoid NULL dereference in ahci_exec() Date: Wed, 4 Nov 2020 10:01:43 -0500 Message-Id: <20201104150153.541326-11-pbonzini@redhat.com> In-Reply-To: <20201104150153.541326-1-pbonzini@redhat.com> References: <20201104150153.541326-1-pbonzini@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=pbonzini@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Received-SPF: pass client-ip=63.128.21.124; envelope-from=pbonzini@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-detected-operating-system: by eggs.gnu.org: First seen = 2020/11/03 22:09:52 X-ACL-Warn: Detected OS = Linux 2.2.x-3.x [generic] [fuzzy] X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.001, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H5=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Peter Maydell Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" From: Peter Maydell In ahci_exec() we attempt to permit the caller to pass a NULL pointer for opts_in (in which case we use a default set of options). However although we check for NULL when setting up the opts variable at the top of the function, we unconditionally dereference opts_in at the end of the function as part of freeing the opts->buffer. Switch to checking whether the final buffer is the same as the buffer we started with, instead of assuming the value we started with is always opts_in->buffer. At the moment all the callers pass a non-NULL opts argument, so we never saw any crashes in practice. Fixes: Coverity CID 1432302 Signed-off-by: Peter Maydell Message-Id: <20201103115257.23623-1-peter.maydell@linaro.org> Signed-off-by: Paolo Bonzini --- tests/qtest/libqos/ahci.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/tests/qtest/libqos/ahci.c b/tests/qtest/libqos/ahci.c index 2946abc15a..fba3e7a954 100644 --- a/tests/qtest/libqos/ahci.c +++ b/tests/qtest/libqos/ahci.c @@ -637,10 +637,13 @@ void ahci_exec(AHCIQState *ahci, uint8_t port, AHCICommand *cmd; int rc; AHCIOpts *opts; + uint64_t buffer_in; opts = g_memdup((opts_in == NULL ? &default_opts : opts_in), sizeof(AHCIOpts)); + buffer_in = opts->buffer; + /* No guest buffer provided, create one. */ if (opts->size && !opts->buffer) { opts->buffer = ahci_alloc(ahci, opts->size); @@ -686,7 +689,7 @@ void ahci_exec(AHCIQState *ahci, uint8_t port, g_assert_cmpint(rc, ==, 0); } ahci_command_free(cmd); - if (opts->buffer != opts_in->buffer) { + if (opts->buffer != buffer_in) { ahci_free(ahci, opts->buffer); } g_free(opts);