From patchwork Wed Apr 14 15:51:37 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Dr. David Alan Gilbert" X-Patchwork-Id: 12203335 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=-15.8 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 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 DFD27C433ED for ; Wed, 14 Apr 2021 16:27:12 +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 3E22D6113B for ; Wed, 14 Apr 2021 16:27:12 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 3E22D6113B 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]:43994 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1lWiMB-000154-4o for qemu-devel@archiver.kernel.org; Wed, 14 Apr 2021 12:27:11 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:34544) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lWhoZ-00004s-Q9 for qemu-devel@nongnu.org; Wed, 14 Apr 2021 11:52:27 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]:49727) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lWhoX-0000Ux-Pk for qemu-devel@nongnu.org; Wed, 14 Apr 2021 11:52:27 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1618415541; 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=nJqGS7tSY8NdiSYT5DpOUCTEwVh1q8tdjJ+aMQIh5jc=; b=MSHPnEKyDNqfkoAeOaQPkYuahuvYsiw8win0VW0xjX/GFnpdWGbOZgsT2yYFQo2WU6oBEm 9ChrLWp7SLIh0CXW/7vU6eQxxspC+A86paWFLfSnN383c+dIiSMT4Cf2N93W8k3wQ6xNGZ 3W4dYWQJfkwSRSvC+yYCh9kaiD4r0v4= 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-534-syUIPLqGMWCza45BIdZahw-1; Wed, 14 Apr 2021 11:52:20 -0400 X-MC-Unique: syUIPLqGMWCza45BIdZahw-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 740B0189C44A for ; Wed, 14 Apr 2021 15:52:19 +0000 (UTC) Received: from dgilbert-t580.localhost (ovpn-115-158.ams2.redhat.com [10.36.115.158]) by smtp.corp.redhat.com (Postfix) with ESMTP id 4443718A49; Wed, 14 Apr 2021 15:52:18 +0000 (UTC) From: "Dr. David Alan Gilbert (git)" To: qemu-devel@nongnu.org, stefanha@redhat.com, vgoyal@redhat.com, virtio-fs@redhat.com Subject: [PATCH v2 25/25] virtiofsd: Ask qemu to drop CAP_FSETID if client asked for it Date: Wed, 14 Apr 2021 16:51:37 +0100 Message-Id: <20210414155137.46522-26-dgilbert@redhat.com> In-Reply-To: <20210414155137.46522-1-dgilbert@redhat.com> References: <20210414155137.46522-1-dgilbert@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=dgilbert@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Received-SPF: pass client-ip=170.10.133.124; envelope-from=dgilbert@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -27 X-Spam_score: -2.8 X-Spam_bar: -- X-Spam_report: (-2.8 / 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_LOW=-0.7, RCVD_IN_MSPIKE_H4=0.001, RCVD_IN_MSPIKE_WL=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: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" From: Vivek Goyal If qemu guest asked to drop CAP_FSETID upon write, send that info to qemu in SLAVE_FS_IO message so that qemu can drop capability before WRITE. This is to make sure that any setuid bit is killed on fd (if there is one set). Signed-off-by: Vivek Goyal --- tools/virtiofsd/buffer.c | 10 ++++++---- tools/virtiofsd/fuse_common.h | 6 +++++- tools/virtiofsd/fuse_lowlevel.h | 6 +++++- tools/virtiofsd/fuse_virtio.c | 5 ++++- tools/virtiofsd/passthrough_ll.c | 2 +- 5 files changed, 21 insertions(+), 8 deletions(-) diff --git a/tools/virtiofsd/buffer.c b/tools/virtiofsd/buffer.c index 8135d52d2a..b4cda7db9a 100644 --- a/tools/virtiofsd/buffer.c +++ b/tools/virtiofsd/buffer.c @@ -203,7 +203,7 @@ static ssize_t fuse_buf_fd_to_fd(const struct fuse_buf *dst, size_t dst_off, static ssize_t fuse_buf_copy_one(fuse_req_t req, const struct fuse_buf *dst, size_t dst_off, const struct fuse_buf *src, size_t src_off, - size_t len) + size_t len, bool dropped_cap_fsetid) { int src_is_fd = src->flags & FUSE_BUF_IS_FD; int dst_is_fd = dst->flags & FUSE_BUF_IS_FD; @@ -211,7 +211,8 @@ static ssize_t fuse_buf_copy_one(fuse_req_t req, int dst_is_phys = src->flags & FUSE_BUF_PHYS_ADDR; if (src_is_phys && !src_is_fd && dst_is_fd) { - return fuse_virtio_write(req, dst, dst_off, src, src_off, len); + return fuse_virtio_write(req, dst, dst_off, src, src_off, len, + dropped_cap_fsetid); } assert(!src_is_phys && !dst_is_phys); if (!src_is_fd && !dst_is_fd) { @@ -267,7 +268,7 @@ static int fuse_bufvec_advance(struct fuse_bufvec *bufv, size_t len) } ssize_t fuse_buf_copy(fuse_req_t req, struct fuse_bufvec *dstv, - struct fuse_bufvec *srcv) + struct fuse_bufvec *srcv, bool dropped_cap_fsetid) { size_t copied = 0, i; @@ -309,7 +310,8 @@ ssize_t fuse_buf_copy(fuse_req_t req, struct fuse_bufvec *dstv, dst_len = dst->size - dstv->off; len = min_size(src_len, dst_len); - res = fuse_buf_copy_one(req, dst, dstv->off, src, srcv->off, len); + res = fuse_buf_copy_one(req, dst, dstv->off, src, srcv->off, len, + dropped_cap_fsetid); if (res < 0) { if (!copied) { return res; diff --git a/tools/virtiofsd/fuse_common.h b/tools/virtiofsd/fuse_common.h index beed03aa93..8a75729be9 100644 --- a/tools/virtiofsd/fuse_common.h +++ b/tools/virtiofsd/fuse_common.h @@ -733,10 +733,14 @@ size_t fuse_buf_size(const struct fuse_bufvec *bufv); * @param req The request this copy is part of * @param dst destination buffer vector * @param src source buffer vector + * @param dropped_cap_fsetid Caller has dropped CAP_FSETID. If work is handed + * over to a different thread/process, CAP_FSETID needs to be dropped + * there as well. * @return actual number of bytes copied or -errno on error */ ssize_t fuse_buf_copy(fuse_req_t req, - struct fuse_bufvec *dst, struct fuse_bufvec *src); + struct fuse_bufvec *dst, struct fuse_bufvec *src, + bool dropped_cap_fsetid); /** * Memory buffer iterator diff --git a/tools/virtiofsd/fuse_lowlevel.h b/tools/virtiofsd/fuse_lowlevel.h index 24e580aafe..dfd7e1525c 100644 --- a/tools/virtiofsd/fuse_lowlevel.h +++ b/tools/virtiofsd/fuse_lowlevel.h @@ -2030,9 +2030,13 @@ int64_t fuse_virtio_io(struct fuse_session *se, VhostUserFSSlaveMsg *msg, * @param src The source (memory) buffer * @param src_off The GPA * @param len Length in bytes + * @param dropped_cap_fsetid Caller dropped CAP_FSETID. If it is being handed + * over to different thread/process, CAP_FSETID needs to be dropped + * before write. */ ssize_t fuse_virtio_write(fuse_req_t req, const struct fuse_buf *dst, size_t dst_off, const struct fuse_buf *src, - size_t src_off, size_t len); + size_t src_off, size_t len, + bool dropped_cap_fsetid); #endif /* FUSE_LOWLEVEL_H_ */ diff --git a/tools/virtiofsd/fuse_virtio.c b/tools/virtiofsd/fuse_virtio.c index 887e79a126..525452d036 100644 --- a/tools/virtiofsd/fuse_virtio.c +++ b/tools/virtiofsd/fuse_virtio.c @@ -1291,7 +1291,7 @@ int64_t fuse_virtio_io(struct fuse_session *se, VhostUserFSSlaveMsg *msg, */ ssize_t fuse_virtio_write(fuse_req_t req, const struct fuse_buf *dst, size_t dst_off, const struct fuse_buf *src, - size_t src_off, size_t len) + size_t src_off, size_t len, bool dropped_cap_fsetid) { VhostUserFSSlaveMsg *msg = g_malloc0(sizeof(VhostUserFSSlaveMsg) + sizeof(VhostUserFSSlaveMsgEntry)); @@ -1311,6 +1311,9 @@ ssize_t fuse_virtio_write(fuse_req_t req, const struct fuse_buf *dst, msg->entries[0].c_offset = (uintptr_t)src->mem + src_off; msg->entries[0].len = len; msg->entries[0].flags = VHOST_USER_FS_FLAG_MAP_W; + if (dropped_cap_fsetid) { + msg->flags |= VHOST_USER_FS_GENFLAG_DROP_FSETID; + } int64_t result = fuse_virtio_io(req->se, msg, dst->fd); fuse_log(FUSE_LOG_DEBUG, "%s: result=%ld\n", __func__, result); diff --git a/tools/virtiofsd/passthrough_ll.c b/tools/virtiofsd/passthrough_ll.c index b3954376b3..d0fa7de538 100644 --- a/tools/virtiofsd/passthrough_ll.c +++ b/tools/virtiofsd/passthrough_ll.c @@ -2301,7 +2301,7 @@ static void lo_write_buf(fuse_req_t req, fuse_ino_t ino, } } - res = fuse_buf_copy(req, &out_buf, in_buf); + res = fuse_buf_copy(req, &out_buf, in_buf, fi->kill_priv); if (res < 0) { fuse_reply_err(req, -res); } else {