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=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,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 F010FC433E0 for ; Tue, 16 Mar 2021 23:32:59 +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 52A8A64EC4 for ; Tue, 16 Mar 2021 23:32:59 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 52A8A64EC4 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=ilande.co.uk Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:50772 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1lMJBK-0003dw-2u for qemu-devel@archiver.kernel.org; Tue, 16 Mar 2021 19:32:58 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:59736) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lMJ9T-0002LM-PW for qemu-devel@nongnu.org; Tue, 16 Mar 2021 19:31:03 -0400 Received: from mail.ilande.co.uk ([2001:41c9:1:41f::167]:33370 helo=mail.default.ilande.uk0.bigv.io) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lMJ9S-0007EJ-8F for qemu-devel@nongnu.org; Tue, 16 Mar 2021 19:31:03 -0400 Received: from host109-156-104-46.range109-156.btcentralplus.com ([109.156.104.46] helo=kentang.home) by mail.default.ilande.uk0.bigv.io with esmtpsa (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1lMJ9P-0006Mg-5X; Tue, 16 Mar 2021 23:31:05 +0000 From: Mark Cave-Ayland To: qemu-devel@nongnu.org, alxndr@bu.edu Date: Tue, 16 Mar 2021 23:30:21 +0000 Message-Id: <20210316233024.13560-2-mark.cave-ayland@ilande.co.uk> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20210316233024.13560-1-mark.cave-ayland@ilande.co.uk> References: <20210316233024.13560-1-mark.cave-ayland@ilande.co.uk> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-SA-Exim-Connect-IP: 109.156.104.46 X-SA-Exim-Mail-From: mark.cave-ayland@ilande.co.uk Subject: [PATCH 1/4] esp: don't underflow cmdfifo if no message out/command data is present X-SA-Exim-Version: 4.2.1 (built Wed, 08 May 2019 21:11:16 +0000) X-SA-Exim-Scanned: Yes (on mail.default.ilande.uk0.bigv.io) Received-SPF: pass client-ip=2001:41c9:1:41f::167; envelope-from=mark.cave-ayland@ilande.co.uk; helo=mail.default.ilande.uk0.bigv.io X-Spam_score_int: -18 X-Spam_score: -1.9 X-Spam_bar: - X-Spam_report: (-1.9 / 5.0 requ) BAYES_00=-1.9, 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: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" If a guest sends a TI (Transfer Information) command without previously sending any message out/command phase data then cmdfifo will underflow triggering an assert reading the IDENTIFY byte. Buglink: https://bugs.launchpad.net/qemu/+bug/1919035 Signed-off-by: Mark Cave-Ayland --- hw/scsi/esp.c | 22 ++++++++++++++-------- 1 file changed, 14 insertions(+), 8 deletions(-) diff --git a/hw/scsi/esp.c b/hw/scsi/esp.c index 507ab363bc..5d3f1ccbc8 100644 --- a/hw/scsi/esp.c +++ b/hw/scsi/esp.c @@ -318,18 +318,24 @@ static void do_busid_cmd(ESPState *s, uint8_t busid) static void do_cmd(ESPState *s) { - uint8_t busid = fifo8_pop(&s->cmdfifo); + uint8_t busid; uint32_t n; - s->cmdfifo_cdb_offset--; + if (fifo8_num_used(&s->cmdfifo)) { + busid = fifo8_pop(&s->cmdfifo); - /* Ignore extended messages for now */ - if (s->cmdfifo_cdb_offset) { - fifo8_pop_buf(&s->cmdfifo, s->cmdfifo_cdb_offset, &n); - s->cmdfifo_cdb_offset = 0; - } + if (s->cmdfifo_cdb_offset) { + s->cmdfifo_cdb_offset--; + + /* Ignore extended messages for now */ + if (s->cmdfifo_cdb_offset) { + fifo8_pop_buf(&s->cmdfifo, s->cmdfifo_cdb_offset, &n); + s->cmdfifo_cdb_offset = 0; + } + } - do_busid_cmd(s, busid); + do_busid_cmd(s, busid); + } } static void satn_pdma_cb(ESPState *s) -- 2.20.1