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=-16.7 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,URIBL_BLOCKED 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 0BA6BC4338F for ; Tue, 24 Aug 2021 08:20:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E51FB61181 for ; Tue, 24 Aug 2021 08:20:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235308AbhHXIVi (ORCPT ); Tue, 24 Aug 2021 04:21:38 -0400 Received: from mail.kernel.org ([198.145.29.99]:55428 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233692AbhHXIVd (ORCPT ); Tue, 24 Aug 2021 04:21:33 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 0058961262 for ; Tue, 24 Aug 2021 08:20:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1629793250; bh=szO3stcJugb0KqsHB8TXgaGEqmKiRGbhqWdW8OKDYnQ=; h=In-Reply-To:References:From:Date:Subject:To:Cc:From; b=mgs3yIZ+H5N90fAmd9PDU4yMu/wAiEaaBSMaRNMk5eCc39jN81cofkEqdDQ2ULgz8 9/98ezW820+o5+nTlSV8X7Kqn3mzR3cZLB9tcu9blTK8G8mfHKSxIobMpj7Sb1KFwJ 7Pz5sxmrZb+d03MLuYzjTyeO/PYw0k/040/KCK7F7jZAHHxrmEMZkRRrGrBhF75dJY BaVwr4/FGxZKJw3ZO8mlxcWT2A1Oy6Rs8HVRNPQbVnFwpi7usA9ceauSKzRTt4i7sT xJWeNd66RlKDNY/n7kYd53ItIOqQHWCjxGhoCvpXpCUVrvWNHzRvp4aF0TeZXQnGpu EX4/2+w7V4H9g== Received: by mail-oo1-f53.google.com with SMTP id z3-20020a4a98430000b029025f4693434bso6249702ooi.3 for ; Tue, 24 Aug 2021 01:20:49 -0700 (PDT) X-Gm-Message-State: AOAM532bPX/M4T/YzwDCAUAeuJ/zYEjaQzBRFgk1ESI4LQoTOuIo6NQW ooxYivfBc/WwQq0NfyrbVQ1IIk6I84HvmyJ0x/s= X-Google-Smtp-Source: ABdhPJxgOzRR5P5BM1MsB37iz01PqUqgu/kIAGpQ42EjDQvxA3L+e4qa4fho67synEmeaHTNRXS58/FNjbjbssqx4Jo= X-Received: by 2002:a4a:e792:: with SMTP id x18mr1116312oov.53.1629793249342; Tue, 24 Aug 2021 01:20:49 -0700 (PDT) MIME-Version: 1.0 Received: by 2002:ac9:1bc6:0:0:0:0:0 with HTTP; Tue, 24 Aug 2021 01:20:48 -0700 (PDT) In-Reply-To: <20210823151357.471691-12-brauner@kernel.org> References: <20210823025816.7496-1-namjae.jeon@samsung.com> <20210823151357.471691-1-brauner@kernel.org> <20210823151357.471691-12-brauner@kernel.org> From: Namjae Jeon Date: Tue, 24 Aug 2021 17:20:48 +0900 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [PATCH 11/11] ksmbd: defer notify_change() call To: Christian Brauner Cc: Steve French , Christoph Hellwig , Namjae Jeon , linux-cifs@vger.kernel.org, Hyunchul Lee , Sergey Senozhatsky , Christian Brauner Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-cifs@vger.kernel.org 2021-08-24 0:13 GMT+09:00, Christian Brauner : > From: Christian Brauner > > When ownership is changed we might in certain scenarios loose the > ability to alter the inode after we changed ownership. This can e.g. > happen when we are on an idmapped mount where uid 0 is mapped to uid > 1000 and uid 1000 is mapped to uid 0. > A caller with fs*id 1000 will be able to create files as *id 1000 on > disk. They will also be able to change ownership of files owned by *id 0 > to *id 1000 but they won't be able to change ownership in the other > direction. This means acl operations following notify_change() would > fail. Move the notify_change() call after the acls have been updated. > This guarantees that we don't end up with spurious "hash value diff" > warnings later on because we managed to change ownership but didn't > manage to alter acls. > > Cc: Steve French > Cc: Christoph Hellwig > Cc: Namjae Jeon > Cc: Hyunchul Lee > Cc: Sergey Senozhatsky > Cc: linux-cifs@vger.kernel.org > Signed-off-by: Christian Brauner > --- > fs/ksmbd/smbacl.c | 21 ++++++++++++++------- > 1 file changed, 14 insertions(+), 7 deletions(-) > > diff --git a/fs/ksmbd/smbacl.c b/fs/ksmbd/smbacl.c > index ef5896297607..8457a3c27c12 100644 > --- a/fs/ksmbd/smbacl.c > +++ b/fs/ksmbd/smbacl.c > @@ -1334,25 +1334,27 @@ int set_info_sec(struct ksmbd_conn *conn, struct > ksmbd_tree_connect *tcon, > newattrs.ia_valid |= ATTR_MODE; > newattrs.ia_mode = (inode->i_mode & ~0777) | (fattr.cf_mode & 0777); > > - inode_lock(inode); > - rc = notify_change(user_ns, path->dentry, &newattrs, NULL); > - inode_unlock(inode); > - if (rc) > - goto out; > - > ksmbd_vfs_remove_acl_xattrs(user_ns, path->dentry); > /* Update posix acls */ > if (IS_ENABLED(CONFIG_FS_POSIX_ACL) && fattr.cf_dacls) { > rc = set_posix_acl(user_ns, inode, > ACL_TYPE_ACCESS, fattr.cf_acls); > + if (rc < 0) > + ksmbd_debug(SMB, > + "Set posix acl(ACL_TYPE_ACCESS) failed, rc : %d\n", > + rc); > if (S_ISDIR(inode->i_mode) && fattr.cf_dacls) You seem to have missed adding braces after adding a debug print. I will directly update it if you don't mind. Thanks! > rc = set_posix_acl(user_ns, inode, > ACL_TYPE_DEFAULT, fattr.cf_dacls); > + if (rc) > + ksmbd_debug(SMB, > + "Set posix acl(ACL_TYPE_DEFAULT) failed, rc : %d\n", > + rc); > } > > /* Check it only calling from SD BUFFER context */ > if (type_check && !(le16_to_cpu(pntsd->type) & DACL_PRESENT)) > - goto out; > + goto out_change; > > if (test_share_config_flag(tcon->share_conf, KSMBD_SHARE_FLAG_ACL_XATTR)) > { > /* Update WinACL in xattr */ > @@ -1361,6 +1363,11 @@ int set_info_sec(struct ksmbd_conn *conn, struct > ksmbd_tree_connect *tcon, > path->dentry, pntsd, ntsd_len); > } > > +out_change: > + inode_lock(inode); > + rc = notify_change(user_ns, path->dentry, &newattrs, NULL); > + inode_unlock(inode); > + > out: > posix_acl_release(fattr.cf_acls); > posix_acl_release(fattr.cf_dacls); > -- > 2.30.2 > >