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=-19.7 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable 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 83BE1C43461 for ; Wed, 12 May 2021 19:53:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4DF3661412 for ; Wed, 12 May 2021 19:53:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S245684AbhELTuy (ORCPT ); Wed, 12 May 2021 15:50:54 -0400 Received: from mail.kernel.org ([198.145.29.99]:53178 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S240880AbhELSEx (ORCPT ); Wed, 12 May 2021 14:04:53 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 4AD4361438; Wed, 12 May 2021 18:03:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1620842624; bh=y3ffrmCDycCem1ujA75aNnFgDchIEtLea4xaD14qP7c=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=k8/rS3Y0bOuuIv/ALhG53zNIL8daqB3ZrPG6eeOoWL0oaBezv+seaN+xoqcD3Qyxf uduVWIjod8wGXVSN6Wf5xOe+cZImdVGWV6eS7TJ/qxZ+Bx5PED7z4hzO0lSayKAOxj GbwqdoklVioxqIKXEvl5a1ywM9z80yrapxdFlC4WJ83UGkiNb2GhHX0ki9+CRuurek 2f6cMZgZzEDaBgcrqi7DiU1FnE6lOalYxhWFEEZSsqmcUEgP42N5s5z3iiMurSLriX aEtgr/uviWxMQOyt2tIXxRWL2EKxupwKjPN8yHgi18zQNvhbQvC0+FArtI9z7r76Kz tzn4ojSF8QJ8w== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Jeff Layton , Xiubo Li , Ilya Dryomov , Sasha Levin , ceph-devel@vger.kernel.org Subject: [PATCH AUTOSEL 5.10 22/34] ceph: don't allow access to MDS-private inodes Date: Wed, 12 May 2021 14:02:53 -0400 Message-Id: <20210512180306.664925-22-sashal@kernel.org> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20210512180306.664925-1-sashal@kernel.org> References: <20210512180306.664925-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Jeff Layton [ Upstream commit d4f6b31d721779d91b5e2f8072478af73b196c34 ] The MDS reserves a set of inodes for its own usage, and these should never be accessible to clients. Add a new helper to vet a proposed inode number against that range, and complain loudly and refuse to create or look it up if it's in it. Also, ensure that the MDS doesn't try to delegate inodes that are in that range or lower. Print a warning if it does, and don't save the range in the xarray. URL: https://tracker.ceph.com/issues/49922 Signed-off-by: Jeff Layton Reviewed-by: Xiubo Li Signed-off-by: Ilya Dryomov Signed-off-by: Sasha Levin --- fs/ceph/export.c | 8 ++++++++ fs/ceph/inode.c | 3 +++ fs/ceph/mds_client.c | 7 +++++++ fs/ceph/super.h | 24 ++++++++++++++++++++++++ 4 files changed, 42 insertions(+) diff --git a/fs/ceph/export.c b/fs/ceph/export.c index e088843a7734..80717234410f 100644 --- a/fs/ceph/export.c +++ b/fs/ceph/export.c @@ -129,6 +129,10 @@ static struct inode *__lookup_inode(struct super_block *sb, u64 ino) vino.ino = ino; vino.snap = CEPH_NOSNAP; + + if (ceph_vino_is_reserved(vino)) + return ERR_PTR(-ESTALE); + inode = ceph_find_inode(sb, vino); if (!inode) { struct ceph_mds_request *req; @@ -212,6 +216,10 @@ static struct dentry *__snapfh_to_dentry(struct super_block *sb, vino.ino = sfh->ino; vino.snap = sfh->snapid; } + + if (ceph_vino_is_reserved(vino)) + return ERR_PTR(-ESTALE); + inode = ceph_find_inode(sb, vino); if (inode) return d_obtain_alias(inode); diff --git a/fs/ceph/inode.c b/fs/ceph/inode.c index 790433cb849e..346fcdfcd3e9 100644 --- a/fs/ceph/inode.c +++ b/fs/ceph/inode.c @@ -56,6 +56,9 @@ struct inode *ceph_get_inode(struct super_block *sb, struct ceph_vino vino) { struct inode *inode; + if (ceph_vino_is_reserved(vino)) + return ERR_PTR(-EREMOTEIO); + inode = iget5_locked(sb, (unsigned long)vino.ino, ceph_ino_compare, ceph_set_ino_cb, &vino); if (!inode) diff --git a/fs/ceph/mds_client.c b/fs/ceph/mds_client.c index 8f1d7500a7ec..d560752b764d 100644 --- a/fs/ceph/mds_client.c +++ b/fs/ceph/mds_client.c @@ -433,6 +433,13 @@ static int ceph_parse_deleg_inos(void **p, void *end, ceph_decode_64_safe(p, end, start, bad); ceph_decode_64_safe(p, end, len, bad); + + /* Don't accept a delegation of system inodes */ + if (start < CEPH_INO_SYSTEM_BASE) { + pr_warn_ratelimited("ceph: ignoring reserved inode range delegation (start=0x%llx len=0x%llx)\n", + start, len); + continue; + } while (len--) { int err = xa_insert(&s->s_delegated_inos, ino = start++, DELEGATED_INO_AVAILABLE, diff --git a/fs/ceph/super.h b/fs/ceph/super.h index 482473e4cce1..c33f744a8e11 100644 --- a/fs/ceph/super.h +++ b/fs/ceph/super.h @@ -529,10 +529,34 @@ static inline int ceph_ino_compare(struct inode *inode, void *data) ci->i_vino.snap == pvino->snap; } +/* + * The MDS reserves a set of inodes for its own usage. These should never + * be accessible by clients, and so the MDS has no reason to ever hand these + * out. The range is CEPH_MDS_INO_MDSDIR_OFFSET..CEPH_INO_SYSTEM_BASE. + * + * These come from src/mds/mdstypes.h in the ceph sources. + */ +#define CEPH_MAX_MDS 0x100 +#define CEPH_NUM_STRAY 10 +#define CEPH_MDS_INO_MDSDIR_OFFSET (1 * CEPH_MAX_MDS) +#define CEPH_INO_SYSTEM_BASE ((6*CEPH_MAX_MDS) + (CEPH_MAX_MDS * CEPH_NUM_STRAY)) + +static inline bool ceph_vino_is_reserved(const struct ceph_vino vino) +{ + if (vino.ino < CEPH_INO_SYSTEM_BASE && + vino.ino >= CEPH_MDS_INO_MDSDIR_OFFSET) { + WARN_RATELIMIT(1, "Attempt to access reserved inode number 0x%llx", vino.ino); + return true; + } + return false; +} static inline struct inode *ceph_find_inode(struct super_block *sb, struct ceph_vino vino) { + if (ceph_vino_is_reserved(vino)) + return NULL; + /* * NB: The hashval will be run through the fs/inode.c hash function * anyway, so there is no need to squash the inode number down to -- 2.30.2