From nobody Wed Nov 19 14:01:55 2025 Delivered-To: importer@patchew.org Authentication-Results: mx.zohomail.com; spf=pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org ARC-Seal: i=1; a=rsa-sha256; t=1615937582; cv=none; d=zohomail.com; s=zohoarc; b=mi7b78dSuhKsdp4uZHH6vX0OxI9+2yJfUVkCZRI88MEGEWY4MYCQns1grP5sPAFqNmw8gpRR/BFrfByoHHxkwIzrsnybBmzntp3q8ZfHghAhHSJxAeG15hp7IUxp78fnOltrKAOMsmfYDLuo5OJUfc8cm8Tf08yP3kN4EEwSqLU= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=zohomail.com; s=zohoarc; t=1615937582; h=Content-Transfer-Encoding:Date:From:In-Reply-To:List-Subscribe:List-Post:List-Id:List-Archive:List-Help:List-Unsubscribe:MIME-Version:Message-ID:References:Sender:Subject:To; bh=OP0k54yqbjanqGf/yorgE+TGQ4bMmrkAczmTe2Q7EMs=; b=E0yy1O8XGRR7qfEYz75tolr+jbVVN/qUkCUJ4VtkzhIRty5wzoFAJtzr/fDsC7UpABjiKQEeye8kRZHqK+e8eC37scuD9pa6QHTJzP0za8WWe2s168YUYRExNhS2KVkcogwpBepTyhDMIos/1NbGDfyxrY1G7eeHecjeaezndn4= ARC-Authentication-Results: i=1; mx.zohomail.com; spf=pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org Return-Path: Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) by mx.zohomail.com with SMTPS id 1615937582795649.3426948712016; Tue, 16 Mar 2021 16:33:02 -0700 (PDT) Received: from localhost ([::1]:50772 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1lMJBN-0003dw-N9 for importer@patchew.org; Tue, 16 Mar 2021 19:33:01 -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: quoted-printable 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 (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) client-ip=209.51.188.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; 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+importer=patchew.org@nongnu.org Sender: "Qemu-devel" Content-Type: text/plain; charset="utf-8" If a guest sends a TI (Transfer Information) command without previously sen= ding 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 Tested-by: Alexander Bulekov --- 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) =20 static void do_cmd(ESPState *s) { - uint8_t busid =3D fifo8_pop(&s->cmdfifo); + uint8_t busid; uint32_t n; =20 - s->cmdfifo_cdb_offset--; + if (fifo8_num_used(&s->cmdfifo)) { + busid =3D fifo8_pop(&s->cmdfifo); =20 - /* Ignore extended messages for now */ - if (s->cmdfifo_cdb_offset) { - fifo8_pop_buf(&s->cmdfifo, s->cmdfifo_cdb_offset, &n); - s->cmdfifo_cdb_offset =3D 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 =3D 0; + } + } =20 - do_busid_cmd(s, busid); + do_busid_cmd(s, busid); + } } =20 static void satn_pdma_cb(ESPState *s) --=20 2.20.1