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=-8.1 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 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 BA16DC433E0 for ; Thu, 21 May 2020 15:35:06 +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 75FA6206F6 for ; Thu, 21 May 2020 15:35:06 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="J23XY9UN" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 75FA6206F6 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]:56214 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jbnDt-0002T8-OE for qemu-devel@archiver.kernel.org; Thu, 21 May 2020 11:35:05 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:41330) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1jbnD2-0001Wo-Fj for qemu-devel@nongnu.org; Thu, 21 May 2020 11:34:12 -0400 Received: from us-smtp-1.mimecast.com ([207.211.31.81]:55261 helo=us-smtp-delivery-1.mimecast.com) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.90_1) (envelope-from ) id 1jbnD0-00077S-JG for qemu-devel@nongnu.org; Thu, 21 May 2020 11:34:12 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1590075249; 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=VIe7T/c0n/LRb4ytd8geZ+MtSpnjSSIIvewJnJ8yqT0=; b=J23XY9UNXbWRZT3wPfLueWqsRkIxTdDLuSA42C7VAFLWf72Q9qjpULgAFW2tTRRfRBLBIa hXHPiCG4PMbpZCFrNxT9meMBpFnt/NqorAcEYEOszMgjquwRl4NPtQle88yV8AjC8twThy 9hhSdgen/xVJ4rd4VevKCQAG9/fqKiw= Received: from mail-wr1-f69.google.com (mail-wr1-f69.google.com [209.85.221.69]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-59-VQmjbP13PNmK47n7linTvQ-1; Thu, 21 May 2020 11:34:04 -0400 X-MC-Unique: VQmjbP13PNmK47n7linTvQ-1 Received: by mail-wr1-f69.google.com with SMTP id p8so3072918wrj.5 for ; Thu, 21 May 2020 08:34:04 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=VIe7T/c0n/LRb4ytd8geZ+MtSpnjSSIIvewJnJ8yqT0=; b=H3GWo+6r/OMW23tNdGSgZnh6S/OM0Yll7w5lc/tmkmpENX/tXMnc/mD8qbllRSRyZ4 2GQOtFqx4+xMEIVAhDZgO0JTau2vhkErNOnsROtFk5L85/NyT7YkBY1sTOOwnXhCHcqj zTAYNm1/T/BeiKzdYbpRA4jP6EDjErhPbhEhjuxV0L5p99Qad6T6uyOAVKUgAj5h4TYT cTefoZQEPP7ov+Z/W3XoIsHr+hz29uoAJyICTtcpFh9UGTmmG4mEfgcndl5e8yQDM94Q +ME1TsaqKQE/qwRwh9uQAhUCgQJSii6l6YdhiEem3ojVQLtUlGsgnoDaG4jPbKCdSQt4 sEhA== X-Gm-Message-State: AOAM531CFoMp/Lvr4CPUwiHi8UGDS1YGXKrMeqdWfBWyQ2Mi6quiWfNT bAtSs2aadQQXGB6x0ANdWf1StiChztZdF07nGwqqyCkHWM62OmuicCX0QLzri9b4f4Ld1xJptRG ZP4xGSEjSDxZTLNc= X-Received: by 2002:a1c:b604:: with SMTP id g4mr9232084wmf.103.1590075243612; Thu, 21 May 2020 08:34:03 -0700 (PDT) X-Google-Smtp-Source: ABdhPJzgd3Yd+fIwblUaSja05UH77+yuV0lLVmIq5K14JZ6EHhv0B267cOpq0sNO/7iyRzK+teB4pg== X-Received: by 2002:a1c:b604:: with SMTP id g4mr9232065wmf.103.1590075243382; Thu, 21 May 2020 08:34:03 -0700 (PDT) Received: from [192.168.178.58] ([151.21.160.154]) by smtp.gmail.com with ESMTPSA id g69sm2051475wmg.15.2020.05.21.08.34.01 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 21 May 2020 08:34:02 -0700 (PDT) Subject: Re: [PATCH v2 2/3] megasas: avoid NULL pointer dereference To: P J P , QEMU Developers References: <20200513192540.1583887-1-ppandit@redhat.com> <20200513192540.1583887-3-ppandit@redhat.com> From: Paolo Bonzini Message-ID: Date: Thu, 21 May 2020 17:34:01 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.6.0 MIME-Version: 1.0 In-Reply-To: <20200513192540.1583887-3-ppandit@redhat.com> Content-Language: en-US X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Received-SPF: pass client-ip=207.211.31.81; envelope-from=pbonzini@redhat.com; helo=us-smtp-delivery-1.mimecast.com X-detected-operating-system: by eggs.gnu.org: First seen = 2020/05/21 04:44:45 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_H4=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_PASS=-0.001, URIBL_BLOCKED=0.001 autolearn=_AUTOLEARN 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: Fam Zheng , Prasad J Pandit , Alexander Bulekov , Ding Ren , =?UTF-8?Q?Marc-Andr=c3=a9_Lureau?= , =?UTF-8?Q?Philippe_Mathieu-Daud=c3=a9?= Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On 13/05/20 21:25, P J P wrote: > From: Prasad J Pandit > > While in megasas_handle_frame(), megasas_enqueue_frame() may > set a NULL frame into MegasasCmd object for a given 'frame_addr' > address. Add check to avoid a NULL pointer dereference issue. > > Reported-by: Alexander Bulekov > Fixes: https://bugs.launchpad.net/qemu/+bug/1878259 > Signed-off-by: Prasad J Pandit > --- > hw/scsi/megasas.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/hw/scsi/megasas.c b/hw/scsi/megasas.c > index 6ce598cd69..b531d88a9b 100644 > --- a/hw/scsi/megasas.c > +++ b/hw/scsi/megasas.c > @@ -504,7 +504,7 @@ static MegasasCmd *megasas_enqueue_frame(MegasasState *s, > cmd->pa = frame; > /* Map all possible frames */ > cmd->frame = pci_dma_map(pcid, frame, &frame_size_p, 0); > - if (frame_size_p != frame_size) { > + if (!cmd->frame || frame_size_p != frame_size) { > trace_megasas_qf_map_failed(cmd->index, (unsigned long)frame); > if (cmd->frame) { > megasas_unmap_frame(s, cmd); > -- 2.25.4 > I think the code here was expecting frame_size_p to be 0 if cmd->frame is NULL. Can you check why this is not the case, or whether it ever was the case? Thanks, Paolo