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 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 smtp.lore.kernel.org (Postfix) with ESMTPS id 71A40CAC587 for ; Tue, 9 Sep 2025 13:52:54 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1uvyle-0000kD-VN; Tue, 09 Sep 2025 09:52:20 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1uvylT-0000i6-DD for qemu-devel@nongnu.org; Tue, 09 Sep 2025 09:52:07 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.129.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1uvylQ-0005Ed-TX for qemu-devel@nongnu.org; Tue, 09 Sep 2025 09:52:06 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1757425922; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=czaGazZmWjRrjyPKQwiMHosoI55jbLoSX4D3jUHlHy4=; b=DMg30Aky4Pw86ytpbrtw7kP0mTbCdf8+faRhzgBWONmMhlM7edhGBtXMsob/0Ih4VSNZ5a ZDMzFzWzfCPQA9sIiy+uzdpn5UzVVLgKDDp/bNQSrseDFIV754DReDLy6BiNf9SOgakguc JVULfCS3oYbX4mxwnLNMStwtjgGc5js= Received: from mx-prod-mc-08.mail-002.prod.us-west-2.aws.redhat.com (ec2-35-165-154-97.us-west-2.compute.amazonaws.com [35.165.154.97]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-677-WC58Ol4iPm6_Tpzdki5RMw-1; Tue, 09 Sep 2025 09:51:59 -0400 X-MC-Unique: WC58Ol4iPm6_Tpzdki5RMw-1 X-Mimecast-MFC-AGG-ID: WC58Ol4iPm6_Tpzdki5RMw_1757425918 Received: from mx-prod-int-06.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-06.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.93]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-08.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 65D301800447; Tue, 9 Sep 2025 13:51:58 +0000 (UTC) Received: from thuth-p1g4.redhat.com (unknown [10.45.224.46]) by mx-prod-int-06.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id EADF11800447; Tue, 9 Sep 2025 13:51:56 +0000 (UTC) From: Thomas Huth To: qemu-devel@nongnu.org Cc: Richard Henderson , David Hildenbrand Subject: [PULL 04/23] system/physmem: Silence warning from ubsan Date: Tue, 9 Sep 2025 15:51:28 +0200 Message-ID: <20250909135147.612345-5-thuth@redhat.com> In-Reply-To: <20250909135147.612345-1-thuth@redhat.com> References: <20250909135147.612345-1-thuth@redhat.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 3.4.1 on 10.30.177.93 Received-SPF: pass client-ip=170.10.129.124; envelope-from=thuth@redhat.com; helo=us-smtp-delivery-124.mimecast.com 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, RCVD_IN_VALIDITY_CERTIFIED_BLOCKED=0.001, RCVD_IN_VALIDITY_RPBL_BLOCKED=0.001, SPF_HELO_PASS=-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: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org From: Thomas Huth When compiling QEMU with --enable-ubsan there is a undefined behavior warning when running the bios-tables-test for example: .../system/physmem.c:3243:13: runtime error: applying non-zero offset 262144 to null pointer #0 0x55ac1df5fbc4 in address_space_write_rom_internal .../system/physmem.c:3243:13 The problem is that buf is indeed NULL if the function is e.g. called with type == FLUSH_CACHE. Add a check to fix the issue. Reviewed-by: David Hildenbrand Signed-off-by: Thomas Huth Message-ID: <20250728172545.314178-1-thuth@redhat.com> --- system/physmem.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/system/physmem.c b/system/physmem.c index f498572fc82..311011156c7 100644 --- a/system/physmem.c +++ b/system/physmem.c @@ -3231,8 +3231,10 @@ static inline MemTxResult address_space_write_rom_internal(AddressSpace *as, } } len -= l; - buf += l; addr += l; + if (buf) { + buf += l; + } } return MEMTX_OK; } -- 2.51.0