From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754636AbdJINNb (ORCPT ); Mon, 9 Oct 2017 09:13:31 -0400 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:42022 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754282AbdJIMpA (ORCPT ); Mon, 9 Oct 2017 08:45:00 -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, "Chao Yu" , "=?UTF-8?q?Ernesto=20A=2E=20Fern=C3=A1ndez?=" , "Jaegeuk Kim" Date: Mon, 09 Oct 2017 13:44:24 +0100 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) Subject: [PATCH 3.16 129/192] f2fs: preserve i_mode if __f2fs_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 3.16.49-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Ernesto A. Fernández commit 14af20fcb1833dd776822361891963c90f7b0262 upstream. When changing a file's acl mask, __f2fs_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 Reviewed-by: Chao Yu Signed-off-by: Jaegeuk Kim [bwh: Backported to 3.16: adjust context] Signed-off-by: Ben Hutchings --- fs/f2fs/acl.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) --- a/fs/f2fs/acl.c +++ b/fs/f2fs/acl.c @@ -202,6 +202,7 @@ static int __f2fs_set_acl(struct inode * void *value = NULL; size_t size = 0; int error; + umode_t mode = inode->i_mode; if (acl) { error = posix_acl_valid(acl); @@ -213,10 +214,10 @@ static int __f2fs_set_acl(struct inode * case ACL_TYPE_ACCESS: name_index = F2FS_XATTR_INDEX_POSIX_ACL_ACCESS; if (acl && !ipage) { - error = posix_acl_update_mode(inode, &inode->i_mode, &acl); + error = posix_acl_update_mode(inode, &mode, &acl); if (error) return error; - set_acl_inode(fi, inode->i_mode); + set_acl_inode(fi, mode); } break;