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=-15.1 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,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 454DFC432BE for ; Wed, 1 Sep 2021 13:23:01 +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 CD37760FC0 for ; Wed, 1 Sep 2021 13:23:00 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org CD37760FC0 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=nongnu.org Received: from localhost ([::1]:41436 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1mLQCi-00075o-1w for qemu-devel@archiver.kernel.org; Wed, 01 Sep 2021 09:23:00 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:48556) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1mLQBd-0005Wc-3l for qemu-devel@nongnu.org; Wed, 01 Sep 2021 09:21:53 -0400 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:34798) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1mLQBa-0003rl-DX for qemu-devel@nongnu.org; Wed, 01 Sep 2021 09:21:52 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1630502509; h=from:from:reply-to: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=kNno79i5fYpT1fEtDo/8L6+fT+mZCC3AktglZ6ssLOQ=; b=TdiOw820Ih4/9nLYCWyfD05h0qhAFIve/XOVZgHvjlvKqlijOB3qYmq4YwQX7OwIeBfQEy crc0JyJ7vq1XUEDvHIB8ciY7qfqnUL0pmEGePhcx7C7tgV5AZqvntepziXHwsT76ZaO0GI WeuFq6kJP6+kzSoJ3KGhV5elRgNdcuw= 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-427-dySwL2_0M-yWF0GtH8h4pA-1; Wed, 01 Sep 2021 09:21:42 -0400 X-MC-Unique: dySwL2_0M-yWF0GtH8h4pA-1 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 5D61810B7455; Wed, 1 Sep 2021 13:21:41 +0000 (UTC) Received: from redhat.com (unknown [10.39.193.162]) by smtp.corp.redhat.com (Postfix) with ESMTPS id C4CE85D9DC; Wed, 1 Sep 2021 13:21:35 +0000 (UTC) Date: Wed, 1 Sep 2021 14:21:33 +0100 From: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= To: Michael Tokarev Subject: Re: [PATCH v3] qemu-sockets: fix unix socket path copy (again) Message-ID: References: <20210901131624.46171-1-mjt@msgid.tls.msk.ru> MIME-Version: 1.0 In-Reply-To: <20210901131624.46171-1-mjt@msgid.tls.msk.ru> User-Agent: Mutt/2.0.7 (2021-05-04) X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=berrange@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit Received-SPF: pass client-ip=216.205.24.124; envelope-from=berrange@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -31 X-Spam_score: -3.2 X-Spam_bar: --- X-Spam_report: (-3.2 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.392, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_LOW=-0.7, 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: , Reply-To: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= Cc: =?utf-8?Q?Marc-Andr=C3=A9?= Lureau , qemu-stable@nongnu.org, qemu-devel@nongnu.org, Peter Maydell Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On Wed, Sep 01, 2021 at 04:16:24PM +0300, Michael Tokarev wrote: > Commit 4cfd970ec188558daa6214f26203fe553fb1e01f added an > assert which ensures the path within an address of a unix > socket returned from the kernel is at least one byte and > does not exceed sun_path buffer. Both of this constraints > are wrong: > > A unix socket can be unnamed, in this case the path is > completely empty (not even \0) > > And some implementations (notable linux) can add extra > trailing byte (\0) _after_ the sun_path buffer if we > passed buffer larger than it (and we do). > > So remove the assertion (since it causes real-life breakage) > but at the same time fix the usage of sun_path. Namely, > we should not access sun_path[0] if kernel did not return > it at all (this is the case for unnamed sockets), > and use the returned salen when copyig actual path as an > upper constraint for the amount of bytes to copy - this > will ensure we wont exceed the information provided by > the kernel, regardless whenever there is a trailing \0 > or not. This also helps with unnamed sockets. > > Note the case of abstract socket, the sun_path is actually > a blob and can contain \0 characters, - it should not be > passed to g_strndup and the like, it should be accessed by > memcpy-like functions. > > Fixes: 4cfd970ec188558daa6214f26203fe553fb1e01f > Fixes: http://bugs.debian.org/993145 > Signed-off-by: Michael Tokarev > CC: qemu-stable@nongnu.org > --- > util/qemu-sockets.c | 13 +++++-------- > 1 file changed, 5 insertions(+), 8 deletions(-) Reviewed-by: Daniel P. Berrangé Regards, Daniel -- |: https://berrange.com -o- https://www.flickr.com/photos/dberrange :| |: https://libvirt.org -o- https://fstop138.berrange.com :| |: https://entangle-photo.org -o- https://www.instagram.com/dberrange :|