From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:51079 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755431AbcBXDx5 (ORCPT ); Tue, 23 Feb 2016 22:53:57 -0500 Subject: Patch "ovl: check dentry positiveness in ovl_cleanup_whiteouts()" has been added to the 4.4-stable tree To: khlebnikov@yandex-team.ru, gregkh@linuxfoundation.org, miklos@szeredi.hu Cc: , From: Date: Tue, 23 Feb 2016 19:24:41 -0800 Message-ID: <1456284281164140@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org List-ID: This is a note to let you know that I've just added the patch titled ovl: check dentry positiveness in ovl_cleanup_whiteouts() to the 4.4-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: ovl-check-dentry-positiveness-in-ovl_cleanup_whiteouts.patch and it can be found in the queue-4.4 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let know about it. >>From 84889d49335627bc770b32787c1ef9ebad1da232 Mon Sep 17 00:00:00 2001 From: Konstantin Khlebnikov Date: Mon, 16 Nov 2015 18:44:11 +0300 Subject: ovl: check dentry positiveness in ovl_cleanup_whiteouts() From: Konstantin Khlebnikov commit 84889d49335627bc770b32787c1ef9ebad1da232 upstream. This patch fixes kernel crash at removing directory which contains whiteouts from lower layers. Cache of directory content passed as "list" contains entries from all layers, including whiteouts from lower layers. So, lookup in upper dir (moved into work at this stage) will return negative entry. Plus this cache is filled long before and we can race with external removal. Example: mkdir -p lower0/dir lower1/dir upper work overlay touch lower0/dir/a lower0/dir/b mknod lower1/dir/a c 0 0 mount -t overlay none overlay -o lowerdir=lower1:lower0,upperdir=upper,workdir=work rm -fr overlay/dir Signed-off-by: Konstantin Khlebnikov Signed-off-by: Miklos Szeredi Signed-off-by: Greg Kroah-Hartman --- fs/overlayfs/readdir.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) --- a/fs/overlayfs/readdir.c +++ b/fs/overlayfs/readdir.c @@ -571,7 +571,8 @@ void ovl_cleanup_whiteouts(struct dentry (int) PTR_ERR(dentry)); continue; } - ovl_cleanup(upper->d_inode, dentry); + if (dentry->d_inode) + ovl_cleanup(upper->d_inode, dentry); dput(dentry); } mutex_unlock(&upper->d_inode->i_mutex); Patches currently in stable-queue which might be from khlebnikov@yandex-team.ru are queue-4.4/ovl-check-dentry-positiveness-in-ovl_cleanup_whiteouts.patch