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=-6.9 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS 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 05B85C2D0DB for ; Thu, 23 Jan 2020 14:52:25 +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 BFDF92051A for ; Thu, 23 Jan 2020 14:52:24 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="H5va55/i" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org BFDF92051A 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]:58496 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1iudqJ-0003nS-Jv for qemu-devel@archiver.kernel.org; Thu, 23 Jan 2020 09:52:23 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:41930) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1iubAw-0004NW-5W for qemu-devel@nongnu.org; Thu, 23 Jan 2020 07:01:36 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1iubAu-0006qZ-Um for qemu-devel@nongnu.org; Thu, 23 Jan 2020 07:01:30 -0500 Received: from us-smtp-1.mimecast.com ([207.211.31.81]:51714 helo=us-smtp-delivery-1.mimecast.com) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1iubAu-0006qQ-RW for qemu-devel@nongnu.org; Thu, 23 Jan 2020 07:01:28 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1579780888; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=8BaKkhOPYBmQm13qrx27mas1rTlYoHzoKc+rGhVsrGg=; b=H5va55/iVKynnKYG6Mje+VpMS9pqsOP8PxrX+ZzVb/lu33rQ+NBI35v6IwPzdvXUhOzWtN EeW/m2wrNPpSt1lSrOiZwBwFJqMDnPdUf+2C6DjMgg9wIZEK0fxrqxMzPmB+NiquyJMHeG uw+SaczocCMvYw6zCnalBwwF/zGq34I= 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-121-7D5pY-EGMwaY3skkFhWbng-1; Thu, 23 Jan 2020 07:01:17 -0500 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 20F6B1005F64 for ; Thu, 23 Jan 2020 12:01:16 +0000 (UTC) Received: from dgilbert-t580.localhost (unknown [10.36.118.0]) by smtp.corp.redhat.com (Postfix) with ESMTP id 6779F85754; Thu, 23 Jan 2020 12:01:15 +0000 (UTC) From: "Dr. David Alan Gilbert (git)" To: qemu-devel@nongnu.org, stefanha@redhat.com Subject: [PULL 105/111] virtiofsd: prevent FUSE_INIT/FUSE_DESTROY races Date: Thu, 23 Jan 2020 11:58:35 +0000 Message-Id: <20200123115841.138849-106-dgilbert@redhat.com> In-Reply-To: <20200123115841.138849-1-dgilbert@redhat.com> References: <20200123115841.138849-1-dgilbert@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.11 X-MC-Unique: 7D5pY-EGMwaY3skkFhWbng-1 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: quoted-printable X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 207.211.31.81 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: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" From: Stefan Hajnoczi When running with multiple threads it can be tricky to handle FUSE_INIT/FUSE_DESTROY in parallel with other request types or in parallel with themselves. Serialize FUSE_INIT and FUSE_DESTROY so that malicious clients cannot trigger race conditions. Signed-off-by: Stefan Hajnoczi Reviewed-by: Masayoshi Mizuma Signed-off-by: Dr. David Alan Gilbert --- tools/virtiofsd/fuse_i.h | 1 + tools/virtiofsd/fuse_lowlevel.c | 18 ++++++++++++++++++ 2 files changed, 19 insertions(+) diff --git a/tools/virtiofsd/fuse_i.h b/tools/virtiofsd/fuse_i.h index a20854f1c4..1447d86866 100644 --- a/tools/virtiofsd/fuse_i.h +++ b/tools/virtiofsd/fuse_i.h @@ -61,6 +61,7 @@ struct fuse_session { struct fuse_req list; struct fuse_req interrupts; pthread_mutex_t lock; + pthread_rwlock_t init_rwlock; int got_destroy; int broken_splice_nonblock; uint64_t notify_ctr; diff --git a/tools/virtiofsd/fuse_lowlevel.c b/tools/virtiofsd/fuse_lowleve= l.c index dab6a31e08..79a4031266 100644 --- a/tools/virtiofsd/fuse_lowlevel.c +++ b/tools/virtiofsd/fuse_lowlevel.c @@ -2428,6 +2428,19 @@ void fuse_session_process_buf_int(struct fuse_sessio= n *se, req->ctx.pid =3D in->pid; req->ch =3D ch; =20 + /* + * INIT and DESTROY requests are serialized, all other request types + * run in parallel. This prevents races between FUSE_INIT and ordinar= y + * requests, FUSE_INIT and FUSE_INIT, FUSE_INIT and FUSE_DESTROY, and + * FUSE_DESTROY and FUSE_DESTROY. + */ + if (in->opcode =3D=3D FUSE_INIT || in->opcode =3D=3D CUSE_INIT || + in->opcode =3D=3D FUSE_DESTROY) { + pthread_rwlock_wrlock(&se->init_rwlock); + } else { + pthread_rwlock_rdlock(&se->init_rwlock); + } + err =3D EIO; if (!se->got_init) { enum fuse_opcode expected; @@ -2485,10 +2498,13 @@ void fuse_session_process_buf_int(struct fuse_sessi= on *se, } else { fuse_ll_ops[in->opcode].func(req, in->nodeid, &iter); } + + pthread_rwlock_unlock(&se->init_rwlock); return; =20 reply_err: fuse_reply_err(req, err); + pthread_rwlock_unlock(&se->init_rwlock); } =20 #define LL_OPTION(n, o, v) \ @@ -2531,6 +2547,7 @@ void fuse_session_destroy(struct fuse_session *se) se->op.destroy(se->userdata); } } + pthread_rwlock_destroy(&se->init_rwlock); pthread_mutex_destroy(&se->lock); free(se->cuse_data); if (se->fd !=3D -1) { @@ -2610,6 +2627,7 @@ struct fuse_session *fuse_session_new(struct fuse_arg= s *args, list_init_req(&se->list); list_init_req(&se->interrupts); fuse_mutex_init(&se->lock); + pthread_rwlock_init(&se->init_rwlock, NULL); =20 memcpy(&se->op, op, op_size); se->owner =3D getuid(); --=20 2.24.1