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=-6.5 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 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 D0E91C433E0 for ; Thu, 11 Jun 2020 20:46:53 +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 9B38A207ED for ; Thu, 11 Jun 2020 20:46:53 +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="KghfFvdO" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 9B38A207ED 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]:55392 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jjU68-0007jc-Uz for qemu-devel@archiver.kernel.org; Thu, 11 Jun 2020 16:46:53 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:55990) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1jjTAL-0001md-Ln for qemu-devel@nongnu.org; Thu, 11 Jun 2020 15:47:09 -0400 Received: from us-smtp-delivery-1.mimecast.com ([205.139.110.120]:36178 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 1jjTAI-0001PF-NE for qemu-devel@nongnu.org; Thu, 11 Jun 2020 15:47:09 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1591904825; 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=DdY3ERWTiaZOd3Bn0BxtqRsKwTUqDQ8SFHOZ6ljXqek=; b=KghfFvdOfa7FxJejRrVbm/gfSqy8g9eytkOgQDw/IIib2xzCko+0m8g9dTh2sNjQPxJWkm Rb+XQRU6oQmJr0JSF1lo0e/+3ObiZIMzh429Z5G2XpCw9HF/P7Y2hK8CWs6mdhwzr0AgVy Ii7WMY5u0i+g6QdE5c0P2l2fYFJzzb4= 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-420-q4dJ48Q4NRykTeqRCBR8Rw-1; Thu, 11 Jun 2020 15:46:53 -0400 X-MC-Unique: q4dJ48Q4NRykTeqRCBR8Rw-1 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 4AB708B8C61; Thu, 11 Jun 2020 19:46:51 +0000 (UTC) Received: from virtlab701.virt.lab.eng.bos.redhat.com (virtlab701.virt.lab.eng.bos.redhat.com [10.19.152.228]) by smtp.corp.redhat.com (Postfix) with ESMTP id C740E60CC0; Thu, 11 Jun 2020 19:46:50 +0000 (UTC) From: Paolo Bonzini To: qemu-devel@nongnu.org Subject: [PULL 080/115] exec: set map length to zero when returning NULL Date: Thu, 11 Jun 2020 15:44:14 -0400 Message-Id: <20200611194449.31468-81-pbonzini@redhat.com> In-Reply-To: <20200611194449.31468-1-pbonzini@redhat.com> References: <20200611194449.31468-1-pbonzini@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Received-SPF: pass client-ip=205.139.110.120; envelope-from=pbonzini@redhat.com; helo=us-smtp-1.mimecast.com X-detected-operating-system: by eggs.gnu.org: First seen = 2020/06/11 14:52:10 X-ACL-Warn: Detected OS = Linux 2.2.x-3.x [generic] [fuzzy] X-Spam_score_int: -30 X-Spam_score: -3.1 X-Spam_bar: --- X-Spam_report: (-3.1 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-1, 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=-0.01, RCVD_IN_MSPIKE_WL=-0.01, SPF_HELO_NONE=0.001, SPF_PASS=-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: Alexander Bulekov , =?UTF-8?q?Philippe=20Mathieu-Daud=C3=A9?= , Prasad J Pandit , Peter Maydell Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" From: Prasad J Pandit When mapping physical memory into host's virtual address space, 'address_space_map' may return NULL if BounceBuffer is in_use. Set and return '*plen = 0' to avoid later NULL pointer dereference. Reported-by: Alexander Bulekov Fixes: https://bugs.launchpad.net/qemu/+bug/1878259 Suggested-by: Paolo Bonzini Suggested-by: Peter Maydell Signed-off-by: Prasad J Pandit Message-Id: <20200526111743.428367-1-ppandit@redhat.com> Reviewed-by: Philippe Mathieu-Daudé Signed-off-by: Paolo Bonzini --- exec.c | 1 + include/exec/memory.h | 3 ++- 2 files changed, 3 insertions(+), 1 deletion(-) diff --git a/exec.c b/exec.c index 9cbde85d8c..778263f1c6 100644 --- a/exec.c +++ b/exec.c @@ -3540,6 +3540,7 @@ void *address_space_map(AddressSpace *as, if (!memory_access_is_direct(mr, is_write)) { if (atomic_xchg(&bounce.in_use, true)) { + *plen = 0; return NULL; } /* Avoid unbounded allocations */ diff --git a/include/exec/memory.h b/include/exec/memory.h index bd7fdd6081..af8ca7824e 100644 --- a/include/exec/memory.h +++ b/include/exec/memory.h @@ -2314,7 +2314,8 @@ bool address_space_access_valid(AddressSpace *as, hwaddr addr, hwaddr len, /* address_space_map: map a physical memory region into a host virtual address * * May map a subset of the requested range, given by and returned in @plen. - * May return %NULL if resources needed to perform the mapping are exhausted. + * May return %NULL and set *@plen to zero(0), if resources needed to perform + * the mapping are exhausted. * Use only for reads OR writes - not for read-modify-write operations. * Use cpu_register_map_client() to know when retrying the map operation is * likely to succeed. -- 2.26.2