From patchwork Thu Mar 11 23:06:31 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Howells X-Patchwork-Id: 12133199 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, 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 88D19C433E0 for ; Thu, 11 Mar 2021 23:07:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 59E7B64F8D for ; Thu, 11 Mar 2021 23:07:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229771AbhCKXGn (ORCPT ); Thu, 11 Mar 2021 18:06:43 -0500 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:31528 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229574AbhCKXGi (ORCPT ); Thu, 11 Mar 2021 18:06:38 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1615503998; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=Sa6wetqoaJXD5avPHDgES9Xzvvsmx+M+iS9y4Mh8zBg=; b=OzdyBMXxQTiMUe9vYpKLmcDEGNH1BlmnoFw2nzNwX0R89ISO/XyQCMiEKIbgkKMfA7xB5q oaD4vgaFWUZGylFtpJFBefWJBCN15zQY3JxmvOyg4o5mf3S819lMr+QoV6CiflQHHAO8MS WQzmWNOucLXBf1DMX7Y2KryByBW6YeU= 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-579-9H2dl-48Pv6GyHW72EhGLQ-1; Thu, 11 Mar 2021 18:06:34 -0500 X-MC-Unique: 9H2dl-48Pv6GyHW72EhGLQ-1 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.phx2.redhat.com [10.5.11.22]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 240DD83DE7F; Thu, 11 Mar 2021 23:06:33 +0000 (UTC) Received: from warthog.procyon.org.uk (ovpn-118-152.rdu2.redhat.com [10.10.118.152]) by smtp.corp.redhat.com (Postfix) with ESMTP id 1C6A310013C1; Thu, 11 Mar 2021 23:06:31 +0000 (UTC) Organization: Red Hat UK Ltd. Registered Address: Red Hat UK Ltd, Amberley Place, 107-111 Peascod Street, Windsor, Berkshire, SI4 1TE, United Kingdom. Registered in England and Wales under Company Registration No. 3798903 Subject: [PATCH v2 1/2] afs: Fix accessing YFS xattrs on a non-YFS server From: David Howells To: linux-afs@lists.infradead.org Cc: Gaja Sophie Peters , Gaja Sophie Peters , dhowells@redhat.com, Gaja Sophie Peters , linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org Date: Thu, 11 Mar 2021 23:06:31 +0000 Message-ID: <161550399136.1983424.7800131837410640702.stgit@warthog.procyon.org.uk> In-Reply-To: <161550398415.1983424.4857046033308089813.stgit@warthog.procyon.org.uk> References: <161550398415.1983424.4857046033308089813.stgit@warthog.procyon.org.uk> User-Agent: StGit/0.23 MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.84 on 10.5.11.22 Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org If someone attempts to access YFS-related xattrs (e.g. afs.yfs.acl) on a file on a non-YFS AFS server (such as OpenAFS), then the kernel will jump to a NULL function pointer because the afs_fetch_acl_operation descriptor doesn't point to a function for issuing an operation on a non-YFS server[1]. Fix this by making afs_wait_for_operation() check that the issue_afs_rpc method is set before jumping to it and setting -ENOTSUPP if not. This fix also covers other potential operations that also only exist on YFS servers. afs_xattr_get/set_yfs() then need to translate -ENOTSUPP to -ENODATA as the former error is internal to the kernel. The bug shows up as an oops like the following: BUG: kernel NULL pointer dereference, address: 0000000000000000 [...] Code: Unable to access opcode bytes at RIP 0xffffffffffffffd6. [...] Call Trace: afs_wait_for_operation+0x83/0x1b0 [kafs] afs_xattr_get_yfs+0xe6/0x270 [kafs] __vfs_getxattr+0x59/0x80 vfs_getxattr+0x11c/0x140 getxattr+0x181/0x250 ? __check_object_size+0x13f/0x150 ? __fput+0x16d/0x250 __x64_sys_fgetxattr+0x64/0xb0 do_syscall_64+0x49/0xc0 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x7fb120a9defe This was triggered with "cp -a" which attempts to copy xattrs, including afs ones, but is easier to reproduce with getfattr, e.g.: getfattr -d -m ".*" /afs/openafs.org/ Fixes: e49c7b2f6de7 ("afs: Build an abstraction around an "operation" concept") Reported-by: Gaja Sophie Peters Signed-off-by: David Howells Tested-by: Gaja Sophie Peters cc: linux-afs@lists.infradead.org Link: http://lists.infradead.org/pipermail/linux-afs/2021-March/003498.html [1] --- fs/afs/fs_operation.c | 7 +++++-- fs/afs/xattr.c | 8 +++++++- 2 files changed, 12 insertions(+), 3 deletions(-) diff --git a/fs/afs/fs_operation.c b/fs/afs/fs_operation.c index 97cab12b0a6c..71c58723763d 100644 --- a/fs/afs/fs_operation.c +++ b/fs/afs/fs_operation.c @@ -181,10 +181,13 @@ void afs_wait_for_operation(struct afs_operation *op) if (test_bit(AFS_SERVER_FL_IS_YFS, &op->server->flags) && op->ops->issue_yfs_rpc) op->ops->issue_yfs_rpc(op); - else + else if (op->ops->issue_afs_rpc) op->ops->issue_afs_rpc(op); + else + op->ac.error = -ENOTSUPP; - op->error = afs_wait_for_call_to_complete(op->call, &op->ac); + if (op->call) + op->error = afs_wait_for_call_to_complete(op->call, &op->ac); } switch (op->error) { diff --git a/fs/afs/xattr.c b/fs/afs/xattr.c index c629caae5002..4934e325a14a 100644 --- a/fs/afs/xattr.c +++ b/fs/afs/xattr.c @@ -231,6 +231,8 @@ static int afs_xattr_get_yfs(const struct xattr_handler *handler, else ret = -ERANGE; } + } else if (ret == -ENOTSUPP) { + ret = -ENODATA; } error_yacl: @@ -256,6 +258,7 @@ static int afs_xattr_set_yfs(const struct xattr_handler *handler, { struct afs_operation *op; struct afs_vnode *vnode = AFS_FS_I(inode); + int ret; if (flags == XATTR_CREATE || strcmp(name, "acl") != 0) @@ -270,7 +273,10 @@ static int afs_xattr_set_yfs(const struct xattr_handler *handler, return afs_put_operation(op); op->ops = &yfs_store_opaque_acl2_operation; - return afs_do_sync_operation(op); + ret = afs_do_sync_operation(op); + if (ret == -ENOTSUPP) + ret = -ENODATA; + return ret; } static const struct xattr_handler afs_xattr_yfs_handler = { From patchwork Thu Mar 11 23:06:38 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Howells X-Patchwork-Id: 12133201 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, URIBL_BLOCKED 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 2E146C433E0 for ; Thu, 11 Mar 2021 23:07:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D4E3C64F8C for ; Thu, 11 Mar 2021 23:07:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229796AbhCKXHX (ORCPT ); Thu, 11 Mar 2021 18:07:23 -0500 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:23486 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229564AbhCKXGp (ORCPT ); Thu, 11 Mar 2021 18:06:45 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1615504004; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=rCnlmIeSflhpUwVGM7LvbR15TVfTJn8RZlzhAMf0UMg=; b=NN4ER6mdBBjk1eTWPP6TCjCe8PhR53YaysmOG9exOe0uRBZVM6a2OsS/HcoZgycu9u2uId Hcsoh9GPkFzAcRxzOp+h44rYMv6e0cRTratzVrFmnvqXS2iyJSUoKG616WrLTXNyQIjFSS whGtFh8PRWQsLi6ZuGg0Se83IbqbY/I= 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-423-XLKk4cgyPpKuQkbKD40uZQ-1; Thu, 11 Mar 2021 18:06:41 -0500 X-MC-Unique: XLKk4cgyPpKuQkbKD40uZQ-1 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.phx2.redhat.com [10.5.11.15]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 64D9BE5760; Thu, 11 Mar 2021 23:06:40 +0000 (UTC) Received: from warthog.procyon.org.uk (ovpn-118-152.rdu2.redhat.com [10.10.118.152]) by smtp.corp.redhat.com (Postfix) with ESMTP id 296155D742; Thu, 11 Mar 2021 23:06:39 +0000 (UTC) Organization: Red Hat UK Ltd. Registered Address: Red Hat UK Ltd, Amberley Place, 107-111 Peascod Street, Windsor, Berkshire, SI4 1TE, United Kingdom. Registered in England and Wales under Company Registration No. 3798903 Subject: [PATCH v2 2/2] afs: Stop listxattr() from listing "afs.*" attributes From: David Howells To: linux-afs@lists.infradead.org Cc: Gaja Sophie Peters , dhowells@redhat.com, Gaja Sophie Peters , linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org Date: Thu, 11 Mar 2021 23:06:38 +0000 Message-ID: <161550399833.1983424.16644306048746346626.stgit@warthog.procyon.org.uk> In-Reply-To: <161550398415.1983424.4857046033308089813.stgit@warthog.procyon.org.uk> References: <161550398415.1983424.4857046033308089813.stgit@warthog.procyon.org.uk> User-Agent: StGit/0.23 MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.15 Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org afs_listxattr() lists all the available special afs xattrs (i.e. those in the "afs.*" space), no matter what type of server we're dealing with. But OpenAFS servers, for example, cannot deal with some of the extra-capable attributes that AuriStor (YFS) servers provide. Unfortunately, the presence of the afs.yfs.* attributes causes errors[1] for anything that tries to read them if the server is of the wrong type. Fix the problem by removing afs_listxattr() so that none of the special xattrs are listed (AFS doesn't support xattrs). It does mean, however, that getfattr won't list them, though they can still be accessed with getxattr() and setxattr(). This can be tested with something like: getfattr -d -m ".*" /afs/example.com/path/to/file With this change, none of the afs.* attributes should be visible. Changes: ver #2: - Hide all of the afs.* xattrs, not just the ACL ones. Fixes: ae46578b963f ("afs: Get YFS ACLs and information through xattrs") Reported-by: Gaja Sophie Peters Signed-off-by: David Howells cc: linux-afs@lists.infradead.org Link: http://lists.infradead.org/pipermail/linux-afs/2021-March/003502.html [1] Link: http://lists.infradead.org/pipermail/linux-afs/2021-March/003567.html # v1 Tested-by: Gaja Sophie Peters Reviewed-by: Marc Dionne --- fs/afs/dir.c | 1 - fs/afs/file.c | 1 - fs/afs/inode.c | 1 - fs/afs/internal.h | 1 - fs/afs/mntpt.c | 1 - fs/afs/xattr.c | 23 ----------------------- 6 files changed, 28 deletions(-) diff --git a/fs/afs/dir.c b/fs/afs/dir.c index 714fcca9af99..17548c1faf02 100644 --- a/fs/afs/dir.c +++ b/fs/afs/dir.c @@ -70,7 +70,6 @@ const struct inode_operations afs_dir_inode_operations = { .permission = afs_permission, .getattr = afs_getattr, .setattr = afs_setattr, - .listxattr = afs_listxattr, }; const struct address_space_operations afs_dir_aops = { diff --git a/fs/afs/file.c b/fs/afs/file.c index 85f5adf21aa0..960b64268623 100644 --- a/fs/afs/file.c +++ b/fs/afs/file.c @@ -43,7 +43,6 @@ const struct inode_operations afs_file_inode_operations = { .getattr = afs_getattr, .setattr = afs_setattr, .permission = afs_permission, - .listxattr = afs_listxattr, }; const struct address_space_operations afs_fs_aops = { diff --git a/fs/afs/inode.c b/fs/afs/inode.c index 1156b2df28d3..12be88716e4c 100644 --- a/fs/afs/inode.c +++ b/fs/afs/inode.c @@ -27,7 +27,6 @@ static const struct inode_operations afs_symlink_inode_operations = { .get_link = page_get_link, - .listxattr = afs_listxattr, }; static noinline void dump_vnode(struct afs_vnode *vnode, struct afs_vnode *parent_vnode) diff --git a/fs/afs/internal.h b/fs/afs/internal.h index b626e38e9ab5..1627b1872812 100644 --- a/fs/afs/internal.h +++ b/fs/afs/internal.h @@ -1509,7 +1509,6 @@ extern int afs_launder_page(struct page *); * xattr.c */ extern const struct xattr_handler *afs_xattr_handlers[]; -extern ssize_t afs_listxattr(struct dentry *, char *, size_t); /* * yfsclient.c diff --git a/fs/afs/mntpt.c b/fs/afs/mntpt.c index 052dab2f5c03..bbb2c210d139 100644 --- a/fs/afs/mntpt.c +++ b/fs/afs/mntpt.c @@ -32,7 +32,6 @@ const struct inode_operations afs_mntpt_inode_operations = { .lookup = afs_mntpt_lookup, .readlink = page_readlink, .getattr = afs_getattr, - .listxattr = afs_listxattr, }; const struct inode_operations afs_autocell_inode_operations = { diff --git a/fs/afs/xattr.c b/fs/afs/xattr.c index 4934e325a14a..7751b0b3f81d 100644 --- a/fs/afs/xattr.c +++ b/fs/afs/xattr.c @@ -11,29 +11,6 @@ #include #include "internal.h" -static const char afs_xattr_list[] = - "afs.acl\0" - "afs.cell\0" - "afs.fid\0" - "afs.volume\0" - "afs.yfs.acl\0" - "afs.yfs.acl_inherited\0" - "afs.yfs.acl_num_cleaned\0" - "afs.yfs.vol_acl"; - -/* - * Retrieve a list of the supported xattrs. - */ -ssize_t afs_listxattr(struct dentry *dentry, char *buffer, size_t size) -{ - if (size == 0) - return sizeof(afs_xattr_list); - if (size < sizeof(afs_xattr_list)) - return -ERANGE; - memcpy(buffer, afs_xattr_list, sizeof(afs_xattr_list)); - return sizeof(afs_xattr_list); -} - /* * Deal with the result of a successful fetch ACL operation. */