From patchwork Thu Mar 25 15:18:22 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Vivek Goyal X-Patchwork-Id: 12164291 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=-16.0 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 359DEC433C1 for ; Thu, 25 Mar 2021 15:19:40 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 00EBF61A17 for ; Thu, 25 Mar 2021 15:19:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231261AbhCYPTM (ORCPT ); Thu, 25 Mar 2021 11:19:12 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]:35497 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231406AbhCYPTC (ORCPT ); Thu, 25 Mar 2021 11:19:02 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1616685541; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=rHW8ynUufSJO3sBpTf1Y0b3Ylr5myqW3HxMSPyzCTJ0=; b=X4RUY7pOsr/3myvbv9Jjf+l7ZvD70bes4ROIF5yaHfK7QSFemqjplekUb6IIRbLVFcW2+2 isC1oQjn7SF/J/IT7OLX/6Rlm+R//4TfSiBFSuMfFN30Y1rrbAyVckRJB6fwXlcLftEqJI Xs2Bez3KfKPGboJMd9PCib476BxYYpY= 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-320-nCE3IV6WOpWNem0iSqho6g-1; Thu, 25 Mar 2021 11:18:59 -0400 X-MC-Unique: nCE3IV6WOpWNem0iSqho6g-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 0C4D0CC656; Thu, 25 Mar 2021 15:18:58 +0000 (UTC) Received: from horse.redhat.com (ovpn-118-78.rdu2.redhat.com [10.10.118.78]) by smtp.corp.redhat.com (Postfix) with ESMTP id E0E25891A5; Thu, 25 Mar 2021 15:18:45 +0000 (UTC) Received: by horse.redhat.com (Postfix, from userid 10451) id 72E8D223D98; Thu, 25 Mar 2021 11:18:45 -0400 (EDT) From: Vivek Goyal To: linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, virtio-fs@redhat.com, miklos@szeredi.hu Cc: vgoyal@redhat.com, lhenriques@suse.de, dgilbert@redhat.com, seth.forshee@canonical.com Subject: [PATCH v2 1/2] fuse: Add support for FUSE_SETXATTR_V2 Date: Thu, 25 Mar 2021 11:18:22 -0400 Message-Id: <20210325151823.572089-2-vgoyal@redhat.com> In-Reply-To: <20210325151823.572089-1-vgoyal@redhat.com> References: <20210325151823.572089-1-vgoyal@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org Fuse client needs to send additional information to file server when it calls SETXATTR(system.posix_acl_access). Right now there is no extra space in fuse_setxattr_in. So introduce a v2 of the structure which has more space in it and can be used to send extra flags. "struct fuse_setxattr_in_v2" is only used if file server opts-in for it using flag FUSE_SETXATTR_V2 during feature negotiations. Signed-off-by: Vivek Goyal --- fs/fuse/acl.c | 2 +- fs/fuse/fuse_i.h | 5 ++++- fs/fuse/inode.c | 4 +++- fs/fuse/xattr.c | 21 +++++++++++++++------ include/uapi/linux/fuse.h | 10 ++++++++++ 5 files changed, 33 insertions(+), 9 deletions(-) diff --git a/fs/fuse/acl.c b/fs/fuse/acl.c index e9c0f916349d..d31260a139d4 100644 --- a/fs/fuse/acl.c +++ b/fs/fuse/acl.c @@ -94,7 +94,7 @@ int fuse_set_acl(struct user_namespace *mnt_userns, struct inode *inode, return ret; } - ret = fuse_setxattr(inode, name, value, size, 0); + ret = fuse_setxattr(inode, name, value, size, 0, 0); kfree(value); } else { ret = fuse_removexattr(inode, name); diff --git a/fs/fuse/fuse_i.h b/fs/fuse/fuse_i.h index 63d97a15ffde..d00bf0b9a38c 100644 --- a/fs/fuse/fuse_i.h +++ b/fs/fuse/fuse_i.h @@ -668,6 +668,9 @@ struct fuse_conn { /** Is setxattr not implemented by fs? */ unsigned no_setxattr:1; + /** Does file server support setxattr_v2 */ + unsigned setxattr_v2:1; + /** Is getxattr not implemented by fs? */ unsigned no_getxattr:1; @@ -1170,7 +1173,7 @@ void fuse_unlock_inode(struct inode *inode, bool locked); bool fuse_lock_inode(struct inode *inode); int fuse_setxattr(struct inode *inode, const char *name, const void *value, - size_t size, int flags); + size_t size, int flags, unsigned extra_flags); ssize_t fuse_getxattr(struct inode *inode, const char *name, void *value, size_t size); ssize_t fuse_listxattr(struct dentry *entry, char *list, size_t size); diff --git a/fs/fuse/inode.c b/fs/fuse/inode.c index b0e18b470e91..1c726df13f80 100644 --- a/fs/fuse/inode.c +++ b/fs/fuse/inode.c @@ -1052,6 +1052,8 @@ static void process_init_reply(struct fuse_mount *fm, struct fuse_args *args, fc->handle_killpriv_v2 = 1; fm->sb->s_flags |= SB_NOSEC; } + if (arg->flags & FUSE_SETXATTR_V2) + fc->setxattr_v2 = 1; } else { ra_pages = fc->max_read / PAGE_SIZE; fc->no_lock = 1; @@ -1095,7 +1097,7 @@ void fuse_send_init(struct fuse_mount *fm) FUSE_PARALLEL_DIROPS | FUSE_HANDLE_KILLPRIV | FUSE_POSIX_ACL | FUSE_ABORT_ERROR | FUSE_MAX_PAGES | FUSE_CACHE_SYMLINKS | FUSE_NO_OPENDIR_SUPPORT | FUSE_EXPLICIT_INVAL_DATA | - FUSE_HANDLE_KILLPRIV_V2; + FUSE_HANDLE_KILLPRIV_V2 | FUSE_SETXATTR_V2; #ifdef CONFIG_FUSE_DAX if (fm->fc->dax) ia->in.flags |= FUSE_MAP_ALIGNMENT; diff --git a/fs/fuse/xattr.c b/fs/fuse/xattr.c index 1a7d7ace54e1..f2aae72653dc 100644 --- a/fs/fuse/xattr.c +++ b/fs/fuse/xattr.c @@ -12,24 +12,33 @@ #include int fuse_setxattr(struct inode *inode, const char *name, const void *value, - size_t size, int flags) + size_t size, int flags, unsigned extra_flags) { struct fuse_mount *fm = get_fuse_mount(inode); FUSE_ARGS(args); struct fuse_setxattr_in inarg; + struct fuse_setxattr_in_v2 inarg_v2; + bool setxattr_v2 = fm->fc->setxattr_v2; int err; if (fm->fc->no_setxattr) return -EOPNOTSUPP; memset(&inarg, 0, sizeof(inarg)); - inarg.size = size; - inarg.flags = flags; + memset(&inarg_v2, 0, sizeof(inarg_v2)); + if (setxattr_v2) { + inarg_v2.size = size; + inarg_v2.flags = flags; + inarg_v2.setxattr_flags = extra_flags; + } else { + inarg.size = size; + inarg.flags = flags; + } args.opcode = FUSE_SETXATTR; args.nodeid = get_node_id(inode); args.in_numargs = 3; - args.in_args[0].size = sizeof(inarg); - args.in_args[0].value = &inarg; + args.in_args[0].size = setxattr_v2 ? sizeof(inarg_v2) : sizeof(inarg); + args.in_args[0].value = setxattr_v2 ? &inarg_v2 : (void *)&inarg; args.in_args[1].size = strlen(name) + 1; args.in_args[1].value = name; args.in_args[2].size = size; @@ -199,7 +208,7 @@ static int fuse_xattr_set(const struct xattr_handler *handler, if (!value) return fuse_removexattr(inode, name); - return fuse_setxattr(inode, name, value, size, flags); + return fuse_setxattr(inode, name, value, size, flags, 0); } static bool no_xattr_list(struct dentry *dentry) diff --git a/include/uapi/linux/fuse.h b/include/uapi/linux/fuse.h index 54442612c48b..1bb555c1c117 100644 --- a/include/uapi/linux/fuse.h +++ b/include/uapi/linux/fuse.h @@ -179,6 +179,7 @@ * 7.33 * - add FUSE_HANDLE_KILLPRIV_V2, FUSE_WRITE_KILL_SUIDGID, FATTR_KILL_SUIDGID * - add FUSE_OPEN_KILL_SUIDGID + * - add FUSE_SETXATTR_V2 */ #ifndef _LINUX_FUSE_H @@ -330,6 +331,7 @@ struct fuse_file_lock { * does not have CAP_FSETID. Additionally upon * write/truncate sgid is killed only if file has group * execute permission. (Same as Linux VFS behavior). + * FUSE_SETXATTR_V2: Does file server support V2 of struct fuse_setxattr_in */ #define FUSE_ASYNC_READ (1 << 0) #define FUSE_POSIX_LOCKS (1 << 1) @@ -360,6 +362,7 @@ struct fuse_file_lock { #define FUSE_MAP_ALIGNMENT (1 << 26) #define FUSE_SUBMOUNTS (1 << 27) #define FUSE_HANDLE_KILLPRIV_V2 (1 << 28) +#define FUSE_SETXATTR_V2 (1 << 29) /** * CUSE INIT request/reply flags @@ -686,6 +689,13 @@ struct fuse_setxattr_in { uint32_t flags; }; +struct fuse_setxattr_in_v2 { + uint32_t size; + uint32_t flags; + uint32_t setxattr_flags; + uint32_t padding; +}; + struct fuse_getxattr_in { uint32_t size; uint32_t padding; From patchwork Thu Mar 25 15:18:23 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Vivek Goyal X-Patchwork-Id: 12164295 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=-16.0 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 6D4A5C433C1 for ; Thu, 25 Mar 2021 15:20:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E7CFA61A1E for ; Thu, 25 Mar 2021 15:20:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231177AbhCYPTk (ORCPT ); Thu, 25 Mar 2021 11:19:40 -0400 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:24234 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231225AbhCYPTM (ORCPT ); Thu, 25 Mar 2021 11:19:12 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1616685551; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=ngHz2qKagXsbyqqzW573XX7EDehDS/8qQ5SoDcQciKI=; b=OX/7yvxQ89bBSbUqEkKmFuVZoBwEaRogDl+SpVrkN6Hb8cinptyFuY2dM5xyt7/EDLSw2W w/SBMTxQm0JMUJNaHdF5NxzF3Hm2un4nLyz2WwFm5KzdLhb1brDX50BoIcIdDfv3cgQcOy 6PdaWVt7kmqRyAzUzdKMES+XHfrFZVA= 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-19-jpuoxVF1P0C_hzLvN1px5g-1; Thu, 25 Mar 2021 11:19:08 -0400 X-MC-Unique: jpuoxVF1P0C_hzLvN1px5g-1 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 3F14C10866A0; Thu, 25 Mar 2021 15:18:58 +0000 (UTC) Received: from horse.redhat.com (ovpn-118-78.rdu2.redhat.com [10.10.118.78]) by smtp.corp.redhat.com (Postfix) with ESMTP id E9FA9712AC; Thu, 25 Mar 2021 15:18:45 +0000 (UTC) Received: by horse.redhat.com (Postfix, from userid 10451) id 78F36223D99; Thu, 25 Mar 2021 11:18:45 -0400 (EDT) From: Vivek Goyal To: linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, virtio-fs@redhat.com, miklos@szeredi.hu Cc: vgoyal@redhat.com, lhenriques@suse.de, dgilbert@redhat.com, seth.forshee@canonical.com Subject: [PATCH v2 2/2] fuse: Add a flag FUSE_SETXATTR_ACL_KILL_SGID to kill SGID Date: Thu, 25 Mar 2021 11:18:23 -0400 Message-Id: <20210325151823.572089-3-vgoyal@redhat.com> In-Reply-To: <20210325151823.572089-1-vgoyal@redhat.com> References: <20210325151823.572089-1-vgoyal@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org When posix access ACL is set, it can have an effect on file mode and it can also need to clear SGID if. - None of caller's group/supplementary groups match file owner group. AND - Caller is not priviliged (No CAP_FSETID). As of now fuser server is responsible for changing the file mode as well. But it does not know whether to clear SGID or not. So add a flag FUSE_SETXATTR_ACL_KILL_SGID and send this info with SETXATTR to let file server know that sgid needs to be cleared as well. Reported-by: Luis Henriques Signed-off-by: Vivek Goyal --- fs/fuse/acl.c | 8 +++++++- include/uapi/linux/fuse.h | 7 +++++++ 2 files changed, 14 insertions(+), 1 deletion(-) diff --git a/fs/fuse/acl.c b/fs/fuse/acl.c index d31260a139d4..8819ceb0a4e5 100644 --- a/fs/fuse/acl.c +++ b/fs/fuse/acl.c @@ -71,6 +71,7 @@ int fuse_set_acl(struct user_namespace *mnt_userns, struct inode *inode, return -EINVAL; if (acl) { + unsigned extra_flags = 0; /* * Fuse userspace is responsible for updating access * permissions in the inode, if needed. fuse_setxattr @@ -94,7 +95,12 @@ int fuse_set_acl(struct user_namespace *mnt_userns, struct inode *inode, return ret; } - ret = fuse_setxattr(inode, name, value, size, 0, 0); + if (fc->setxattr_v2 && + !in_group_p(i_gid_into_mnt(&init_user_ns, inode)) && + !capable_wrt_inode_uidgid(&init_user_ns, inode, CAP_FSETID)) + extra_flags |= FUSE_SETXATTR_ACL_KILL_SGID; + + ret = fuse_setxattr(inode, name, value, size, 0, extra_flags); kfree(value); } else { ret = fuse_removexattr(inode, name); diff --git a/include/uapi/linux/fuse.h b/include/uapi/linux/fuse.h index 1bb555c1c117..08c11a7beaa7 100644 --- a/include/uapi/linux/fuse.h +++ b/include/uapi/linux/fuse.h @@ -180,6 +180,7 @@ * - add FUSE_HANDLE_KILLPRIV_V2, FUSE_WRITE_KILL_SUIDGID, FATTR_KILL_SUIDGID * - add FUSE_OPEN_KILL_SUIDGID * - add FUSE_SETXATTR_V2 + * - add FUSE_SETXATTR_ACL_KILL_SGID */ #ifndef _LINUX_FUSE_H @@ -454,6 +455,12 @@ struct fuse_file_lock { */ #define FUSE_OPEN_KILL_SUIDGID (1 << 0) +/** + * setxattr flags + * FUSE_SETXATTR_ACL_KILL_SGID: Clear SGID when system.posix_acl_access is set + */ +#define FUSE_SETXATTR_ACL_KILL_SGID (1 << 0) + enum fuse_opcode { FUSE_LOOKUP = 1, FUSE_FORGET = 2, /* no reply */