From nobody Mon Feb 9 06:00:29 2026 Delivered-To: importer@patchew.org Authentication-Results: mx.zohomail.com; dkim=pass; spf=pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; dmarc=pass(p=none dis=none) header.from=redhat.com ARC-Seal: i=1; a=rsa-sha256; t=1612899609; cv=none; d=zohomail.com; s=zohoarc; b=e1R19KPv97A9Ucnf+c36u1CwzAQABtAPJoCVxW+ZqeA8/zGeqPO0i39O1vv7U7bQRrhYdoj0uOHzc3xfRxU/FZto6hRfqvmHRDEReaeu0AjiaTNZfgh2SnpJUWyuhRQ8w5II1/GJ3Yy+qQKQxn7loz9U40aijix4WPv7ISRAwOU= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=zohomail.com; s=zohoarc; t=1612899609; h=Content-Type:Content-Transfer-Encoding:Date:From:In-Reply-To:List-Subscribe:List-Post:List-Id:List-Archive:List-Help:List-Unsubscribe:MIME-Version:Message-ID:References:Sender:Subject:To; bh=hnO1JFIT4ig1h7ZZw0NFiElN0hfpmt4U9rvIhq7owdQ=; b=auB1HxVWySnqlvlIcpoCwO5uceXeU/N7I8JbEWzrBNqUJDoJTncy4p7xrUt9RdPsVdDVD97UYgV0VtaP1xLqAHcR+qBwzyZXtMNErqRVqL5PbYYDjRnhR2HMtP6i8nKXDnJI77xzLhKFmICK/tKP+UGiWOrhDHFT3KcBs6DtGn8= ARC-Authentication-Results: i=1; mx.zohomail.com; dkim=pass; spf=pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; dmarc=pass header.from= (p=none dis=none) header.from= Return-Path: Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) by mx.zohomail.com with SMTPS id 1612899609135338.463701956064; Tue, 9 Feb 2021 11:40:09 -0800 (PST) Received: from localhost ([::1]:41102 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1l9Yrn-00055u-Re for importer@patchew.org; Tue, 09 Feb 2021 14:40:07 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:52640) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1l9YLb-0004NP-S4 for qemu-devel@nongnu.org; Tue, 09 Feb 2021 14:06:51 -0500 Received: from us-smtp-delivery-124.mimecast.com ([63.128.21.124]:57510) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.90_1) (envelope-from ) id 1l9YLZ-0002df-M6 for qemu-devel@nongnu.org; Tue, 09 Feb 2021 14:06:51 -0500 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-276-z25y2fuZPw2Pq2rvaAKt8A-1; Tue, 09 Feb 2021 14:06:46 -0500 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 BAD321005501 for ; Tue, 9 Feb 2021 19:06:44 +0000 (UTC) Received: from dgilbert-t580.localhost (ovpn-112-66.ams2.redhat.com [10.36.112.66]) by smtp.corp.redhat.com (Postfix) with ESMTP id 4833B60C04; Tue, 9 Feb 2021 19:06:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1612897607; 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=hnO1JFIT4ig1h7ZZw0NFiElN0hfpmt4U9rvIhq7owdQ=; b=NNh88c+XjPhrxxcxsn59r1BctH911Lhcc9wXzrWERqeJ+5Eglgd5mqOrnweLlM2WYh6JSP XDRlIwiMfg5JZ0QhOHdxItfLd8zaZV5BXE/4L/Nvhnp/lsK9SwmWD9oN4fXHBRndo6TLww ow/ml0KfFlDweqvb/s0kaH9noQfJ2ZI= X-MC-Unique: z25y2fuZPw2Pq2rvaAKt8A-1 From: "Dr. David Alan Gilbert (git)" To: qemu-devel@nongnu.org, vgoyal@redhat.com, stefanha@redhat.com, virtio-fs@redhat.com, marcandre.lureau@redhat.com, mst@redhat.com Subject: [PATCH 24/24] virtiofsd: Ask qemu to drop CAP_FSETID if client asked for it Date: Tue, 9 Feb 2021 19:02:24 +0000 Message-Id: <20210209190224.62827-25-dgilbert@redhat.com> In-Reply-To: <20210209190224.62827-1-dgilbert@redhat.com> References: <20210209190224.62827-1-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 Content-Transfer-Encoding: quoted-printable Received-SPF: pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) client-ip=209.51.188.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Received-SPF: pass client-ip=63.128.21.124; envelope-from=dgilbert@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -33 X-Spam_score: -3.4 X-Spam_bar: --- X-Spam_report: (-3.4 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.57, 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+importer=patchew.org@nongnu.org Sender: "Qemu-devel" X-ZohoMail-DKIM: pass (identity @redhat.com) Content-Type: text/plain; charset="utf-8" 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_of= f, const struct fuse_buf *src, size_t src_of= f, - size_t len) + size_t len, bool dropped_cap_fsetid) { int src_is_fd =3D src->flags & FUSE_BUF_IS_FD; int dst_is_fd =3D 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 =3D src->flags & FUSE_BUF_PHYS_ADDR; =20 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) } =20 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 =3D 0, i; =20 @@ -309,7 +310,8 @@ ssize_t fuse_buf_copy(fuse_req_t req, struct fuse_bufve= c *dstv, dst_len =3D dst->size - dstv->off; len =3D min_size(src_len, dst_len); =20 - res =3D fuse_buf_copy_one(req, dst, dstv->off, src, srcv->off, len= ); + res =3D 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 05d56883dd..8cf9a5544e 100644 --- a/tools/virtiofsd/fuse_common.h +++ b/tools/virtiofsd/fuse_common.h @@ -718,10 +718,14 @@ 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 han= ded + * over to a different thread/process, CAP_FSETID needs to be dropp= ed + * 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); =20 /** * Memory buffer iterator diff --git a/tools/virtiofsd/fuse_lowlevel.h b/tools/virtiofsd/fuse_lowleve= l.h index b36140c565..21e1ee24d0 100644 --- a/tools/virtiofsd/fuse_lowlevel.h +++ b/tools/virtiofsd/fuse_lowlevel.h @@ -2029,9 +2029,13 @@ int64_t fuse_virtio_io(struct fuse_session *se, Vhos= tUserFSSlaveMsg *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 han= ded + * 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); =20 #endif /* FUSE_LOWLEVEL_H_ */ diff --git a/tools/virtiofsd/fuse_virtio.c b/tools/virtiofsd/fuse_virtio.c index 316d1f2463..6cdf131bc7 100644 --- a/tools/virtiofsd/fuse_virtio.c +++ b/tools/virtiofsd/fuse_virtio.c @@ -1189,7 +1189,7 @@ int64_t fuse_virtio_io(struct fuse_session *se, Vhost= UserFSSlaveMsg *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_fse= tid) { VhostUserFSSlaveMsg msg =3D { 0 }; =20 @@ -1205,6 +1205,9 @@ ssize_t fuse_virtio_write(fuse_req_t req, const struc= t fuse_buf *dst, msg.c_offset[0] =3D (uintptr_t)src->mem + src_off; msg.len[0] =3D len; msg.flags[0] =3D VHOST_USER_FS_FLAG_MAP_W; + if (dropped_cap_fsetid) { + msg.gen_flags |=3D VHOST_USER_FS_GENFLAG_DROP_FSETID; + } =20 int64_t result =3D fuse_virtio_io(req->se, &msg, dst->fd); fuse_log(FUSE_LOG_DEBUG, "%s: result=3D%ld\n", __func__, result); diff --git a/tools/virtiofsd/passthrough_ll.c b/tools/virtiofsd/passthrough= _ll.c index 5baf4f1d50..8dba129785 100644 --- a/tools/virtiofsd/passthrough_ll.c +++ b/tools/virtiofsd/passthrough_ll.c @@ -2135,7 +2135,7 @@ static void lo_write_buf(fuse_req_t req, fuse_ino_t i= no, } } =20 - res =3D fuse_buf_copy(req, &out_buf, in_buf); + res =3D fuse_buf_copy(req, &out_buf, in_buf, fi->kill_priv); if (res < 0) { fuse_reply_err(req, -res); } else { --=20 2.29.2