From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754659AbdJINBi (ORCPT ); Mon, 9 Oct 2017 09:01:38 -0400 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:41899 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754377AbdJIMpR (ORCPT ); Mon, 9 Oct 2017 08:45:17 -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" , "=?UTF-8?q?Ernesto=20A=2E=20Fern=C3=A1ndez?=" Date: Mon, 09 Oct 2017 13:30:34 +0100 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) Subject: [PATCH 3.2 53/74] reiserfs: preserve i_mode if __reiserfs_set_acl() fails 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 3.2.94-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Ernesto A. Fernández commit fcea8aed91f53b51f9b943dc01f12d8aa666c720 upstream. When changing a file's acl mask, reiserfs_set_acl() will first set the group bits of i_mode to the value of the mask, and only then set the actual extended attribute representing the new acl. If the second part fails (due to lack of space, for example) and the file had no acl attribute to begin with, the system will from now on assume that the mask permission bits are actual group permission bits, potentially granting access to the wrong users. Prevent this by only changing the inode mode after the acl has been set. Signed-off-by: Ernesto A. Fernández Signed-off-by: Jan Kara [bwh: Backported to 3.2: adjust context] Signed-off-by: Ben Hutchings --- --- a/fs/reiserfs/xattr_acl.c +++ b/fs/reiserfs/xattr_acl.c @@ -315,14 +315,19 @@ reiserfs_set_acl(struct reiserfs_transac int type, struct posix_acl *acl) { int error; + int update_mode = 0; + umode_t mode = inode->i_mode; if (type == ACL_TYPE_ACCESS && acl) { - error = posix_acl_update_mode(inode, &inode->i_mode, - &acl); + error = posix_acl_update_mode(inode, &mode, &acl); if (error) return error; + update_mode = 1; } - return __reiserfs_set_acl(th, inode, type, acl); + error = __reiserfs_set_acl(th, inode, type, acl); + if (!error && update_mode) + inode->i_mode = mode; + return error; } /* dir->i_mutex: locked,