From patchwork Thu Sep 3 18:31:38 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Prasad Pandit X-Patchwork-Id: 274644 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,DKIM_INVALID, DKIM_SIGNED, 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 1B4E0C433E9 for ; Thu, 3 Sep 2020 18:34:57 +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 BD8E720709 for ; Thu, 3 Sep 2020 18:34:56 +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="ZebIJuR9" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org BD8E720709 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]:46952 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1kDu4V-0004iY-OD for qemu-devel@archiver.kernel.org; Thu, 03 Sep 2020 14:34:55 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:44230) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1kDu3Y-0004Hn-Jc for qemu-devel@nongnu.org; Thu, 03 Sep 2020 14:33:56 -0400 Received: from us-smtp-delivery-1.mimecast.com ([205.139.110.120]:36664 helo=us-smtp-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 1kDu3W-0003C5-4A for qemu-devel@nongnu.org; Thu, 03 Sep 2020 14:33:55 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1599158032; 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; bh=mhuHg2UUlQ5+ztLojjQBo/7d9vvLmT7q8pONMIvh4k4=; b=ZebIJuR9EN0NJmNn6FawrGD7XQHVPKrHqIIgrVlAmsfXeo1TFgs11bZQLzcLjV6Nk1Wpf7 cGLIJizjyhLZzKUcR6akEmaDPHT1izqV5NHIwcqyyoBByxqct+hIH4ic3Wf+vgNG36D02l jklpvy4I2ihTuJ2R4jVeXYh0sXz38D4= 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-4-jzfuBiPYNAmKQ5DWOEd_DQ-1; Thu, 03 Sep 2020 14:33:47 -0400 X-MC-Unique: jzfuBiPYNAmKQ5DWOEd_DQ-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 4B6E6425DE; Thu, 3 Sep 2020 18:33:46 +0000 (UTC) Received: from localhost.localdomain (ovpn-113-31.rdu2.redhat.com [10.10.113.31]) by smtp.corp.redhat.com (Postfix) with ESMTPS id B12521C4; Thu, 3 Sep 2020 18:33:42 +0000 (UTC) From: P J P To: =?utf-8?q?Philippe_Mathieu-Daud=C3=A9?= Subject: [PATCH v2] hw/ide: check null block before _cancel_dma_sync Date: Fri, 4 Sep 2020 00:01:38 +0530 Message-Id: <20200903183138.2161977-1-ppandit@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=ppandit@redhat.com X-Mimecast-Spam-Score: 0.001 X-Mimecast-Originator: redhat.com Received-SPF: pass client-ip=205.139.110.120; envelope-from=ppandit@redhat.com; helo=us-smtp-1.mimecast.com X-detected-operating-system: by eggs.gnu.org: First seen = 2020/09/03 01:58:20 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_H2=-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: John Snow , Ruhr-University , QEMU Developers , qemu-block@nongnu.org, Prasad J Pandit Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" From: Prasad J Pandit When cancelling an i/o operation via ide_cancel_dma_sync(), a block pointer may be null. Add check to avoid null pointer dereference. -> https://ruhr-uni-bochum.sciebo.de/s/NNWP2GfwzYKeKwE?path=%2Fide_nullptr1 ==1803100==Hint: address points to the zero page. #0 blk_bs ../block/block-backend.c:714 #1 blk_drain ../block/block-backend.c:1715 #2 ide_cancel_dma_sync ../hw/ide/core.c:723 #3 bmdma_cmd_writeb ../hw/ide/pci.c:298 #4 bmdma_write ../hw/ide/piix.c:75 #5 memory_region_write_accessor ../softmmu/memory.c:483 #6 access_with_adjusted_size ../softmmu/memory.c:544 #7 memory_region_dispatch_write ../softmmu/memory.c:1465 #8 flatview_write_continue ../exec.c:3176 ... Reported-by: Ruhr-University Signed-off-by: Prasad J Pandit --- hw/ide/core.c | 1 + hw/ide/pci.c | 5 ++++- 2 files changed, 5 insertions(+), 1 deletion(-) Update v2: use an assert() call -> https://lists.nongnu.org/archive/html/qemu-devel/2020-08/msg08336.html diff --git a/hw/ide/core.c b/hw/ide/core.c index f76f7e5234..8105187f49 100644 --- a/hw/ide/core.c +++ b/hw/ide/core.c @@ -718,6 +718,7 @@ void ide_cancel_dma_sync(IDEState *s) * whole DMA operation will be submitted to disk with a single * aio operation with preadv/pwritev. */ + assert(s->blk); if (s->bus->dma->aiocb) { trace_ide_cancel_dma_sync_remaining(); blk_drain(s->blk); diff --git a/hw/ide/pci.c b/hw/ide/pci.c index b50091b615..b47e675456 100644 --- a/hw/ide/pci.c +++ b/hw/ide/pci.c @@ -295,7 +295,10 @@ void bmdma_cmd_writeb(BMDMAState *bm, uint32_t val) /* Ignore writes to SSBM if it keeps the old value */ if ((val & BM_CMD_START) != (bm->cmd & BM_CMD_START)) { if (!(val & BM_CMD_START)) { - ide_cancel_dma_sync(idebus_active_if(bm->bus)); + IDEState *s = idebus_active_if(bm->bus); + if (s->blk) { + ide_cancel_dma_sync(s); + } bm->status &= ~BM_STATUS_DMAING; } else { bm->cur_addr = bm->addr;