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=-17.6 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, 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 35141C432BE for ; Tue, 31 Aug 2021 17:41:32 +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 B062360FE8 for ; Tue, 31 Aug 2021 17:41:31 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org B062360FE8 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; 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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=-0.391, 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: Michael Tokarev , qemu-devel , qemu-stable Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On Tue, Aug 31, 2021 at 09:22:01PM +0400, Marc-André Lureau wrote: > Hi > > On Tue, Aug 31, 2021 at 9:17 PM Michael Tokarev wrote: > > > 31.08.2021 01:54, Michael Tokarev wrote: > > > Linux kernel can return size of af_unix socket to be > > > one byte larger than sockaddr_un structure - adding > > > the trailing zero byte. > > > > > > Signed-off-by: Michael Tokarev > > > Fixes: 4cfd970ec188558daa6214f26203fe553fb1e01f (first in 6.1.0) > > > Cc: qemu-stable@nongnu.org > > > > > > diff --git a/util/qemu-sockets.c b/util/qemu-sockets.c > > > index f2f3676d1f..83926dc2bc 100644 > > > --- a/util/qemu-sockets.c > > > +++ b/util/qemu-sockets.c > > > @@ -1345,8 +1345,9 @@ socket_sockaddr_to_address_unix(struct > > sockaddr_storage *sa, > > > SocketAddress *addr; > > > struct sockaddr_un *su = (struct sockaddr_un *)sa; > > > > > > + /* kernel might have added \0 terminator to non-abstract socket */ > > > assert(salen >= sizeof(su->sun_family) + 1 && > > > - salen <= sizeof(struct sockaddr_un)); > > > + salen <= sizeof(struct sockaddr_un) + su->sun_path[0] ? 1 : > > 0); > > > > > > addr = g_new0(SocketAddress, 1); > > > addr->type = SOCKET_ADDRESS_TYPE_UNIX; > > > > Actually, this is not sufficient. > > > > While this change fixes one issue (the famous trailing null byte \0), > > the actual assertion failure occurs because salen = 2, ie, too SMALL, > > not too large. > > > > So it looks like libvirt provides an unnamed socket there, -- > > maybe from a socketpair(2)? > > > > Yes No, libvirt binds to a named socket path and passes in a pre-opened FD for the listener socket. There shouldn't be any socketpair involved. 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 :|