From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754568AbdJINIu (ORCPT ); Mon, 9 Oct 2017 09:08:50 -0400 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:42074 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751184AbdJIMpB (ORCPT ); Mon, 9 Oct 2017 08:45:01 -0400 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, "Jan Kara" , "Theodore Ts'o" , "Andreas Gruenbacher" Date: Mon, 09 Oct 2017 13:44:24 +0100 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) Subject: [PATCH 3.16 127/192] ext4: Don't clear SGID when inheriting ACLs In-Reply-To: X-SA-Exim-Connect-IP: 2a02:8011:400e:2:6f00:88c8:c921:d332 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.16.49-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Jan Kara commit a3bb2d5587521eea6dab2d05326abb0afb460abd upstream. When new directory 'DIR1' is created in a directory 'DIR0' with SGID bit set, DIR1 is expected to have SGID bit set (and owning group equal to the owning group of 'DIR0'). However when 'DIR0' also has some default ACLs that 'DIR1' inherits, setting these ACLs will result in SGID bit on 'DIR1' to get cleared if user is not member of the owning group. Fix the problem by moving posix_acl_update_mode() out of __ext4_set_acl() into ext4_set_acl(). That way the function will not be called when inheriting ACLs which is what we want as it prevents SGID bit clearing and the mode has been properly set by posix_acl_create() anyway. Fixes: 073931017b49d9458aa351605b43a7e34598caef Signed-off-by: Theodore Ts'o Signed-off-by: Jan Kara Reviewed-by: Andreas Gruenbacher [bwh: Backported to 3.16: - Keep using ext4_current_time() - Adjust context] Signed-off-by: Ben Hutchings --- fs/ext4/acl.c | 28 +++++++++++++++------------- 1 file changed, 15 insertions(+), 13 deletions(-) --- a/fs/ext4/acl.c +++ b/fs/ext4/acl.c @@ -196,18 +196,10 @@ __ext4_set_acl(handle_t *handle, struct void *value = NULL; size_t size = 0; int error; - int update_mode = 0; - umode_t mode = inode->i_mode; switch (type) { case ACL_TYPE_ACCESS: name_index = EXT4_XATTR_INDEX_POSIX_ACL_ACCESS; - if (acl) { - error = posix_acl_update_mode(inode, &mode, &acl); - if (error) - return error; - update_mode = 1; - } break; case ACL_TYPE_DEFAULT: @@ -231,11 +223,6 @@ __ext4_set_acl(handle_t *handle, struct kfree(value); if (!error) { set_cached_acl(inode, type, acl); - if (update_mode) { - inode->i_mode = mode; - inode->i_ctime = ext4_current_time(inode); - ext4_mark_inode_dirty(handle, inode); - } } return error; @@ -246,6 +233,8 @@ ext4_set_acl(struct inode *inode, struct { handle_t *handle; int error, retries = 0; + umode_t mode = inode->i_mode; + int update_mode = 0; retry: handle = ext4_journal_start(inode, EXT4_HT_XATTR, @@ -253,7 +242,20 @@ retry: if (IS_ERR(handle)) return PTR_ERR(handle); + if ((type == ACL_TYPE_ACCESS) && acl) { + error = posix_acl_update_mode(inode, &mode, &acl); + if (error) + goto out_stop; + update_mode = 1; + } + error = __ext4_set_acl(handle, inode, type, acl); + if (!error && update_mode) { + inode->i_mode = mode; + inode->i_ctime = ext4_current_time(inode); + ext4_mark_inode_dirty(handle, inode); + } +out_stop: ext4_journal_stop(handle); if (error == -ENOSPC && ext4_should_retry_alloc(inode->i_sb, &retries)) goto retry;