From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932288AbcFEWSn (ORCPT ); Sun, 5 Jun 2016 18:18:43 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:43379 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753885AbcFEVw6 (ORCPT ); Sun, 5 Jun 2016 17:52:58 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Mikulas Patocka , Linus Torvalds Subject: [PATCH 4.6 027/121] affs: fix remount failure when there are no options changed Date: Sun, 5 Jun 2016 14:42:59 -0700 Message-Id: <20160605214418.538215850@linuxfoundation.org> X-Mailer: git-send-email 2.8.3 In-Reply-To: <20160605214417.708509043@linuxfoundation.org> References: <20160605214417.708509043@linuxfoundation.org> User-Agent: quilt/0.64 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.6-stable review patch. If anyone has any objections, please let me know. ------------------ From: Mikulas Patocka commit 01d6e08711bf90bc4d7ead14a93a0cbd73b1896a upstream. Commit c8f33d0bec99 ("affs: kstrdup() memory handling") checks if the kstrdup function returns NULL due to out-of-memory condition. However, if we are remounting a filesystem with no change to filesystem-specific options, the parameter data is NULL. In this case, kstrdup returns NULL (because it was passed NULL parameter), although no out of memory condition exists. The mount syscall then fails with ENOMEM. This patch fixes the bug. We fail with ENOMEM only if data is non-NULL. The patch also changes the call to replace_mount_options - if we didn't pass any filesystem-specific options, we don't call replace_mount_options (thus we don't erase existing reported options). Fixes: c8f33d0bec99 ("affs: kstrdup() memory handling") Signed-off-by: Mikulas Patocka Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman --- fs/affs/super.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) --- a/fs/affs/super.c +++ b/fs/affs/super.c @@ -528,7 +528,7 @@ affs_remount(struct super_block *sb, int char *prefix = NULL; new_opts = kstrdup(data, GFP_KERNEL); - if (!new_opts) + if (data && !new_opts) return -ENOMEM; pr_debug("%s(flags=0x%x,opts=\"%s\")\n", __func__, *flags, data); @@ -546,7 +546,8 @@ affs_remount(struct super_block *sb, int } flush_delayed_work(&sbi->sb_work); - replace_mount_options(sb, new_opts); + if (new_opts) + replace_mount_options(sb, new_opts); sbi->s_flags = mount_flags; sbi->s_mode = mode;