From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:48325 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932172AbcJZIQE (ORCPT ); Wed, 26 Oct 2016 04:16:04 -0400 Subject: Patch "ovl: copy_up_xattr(): use strnlen" has been added to the 4.4-stable tree To: mszeredi@redhat.com, gregkh@linuxfoundation.org Cc: , From: Date: Wed, 26 Oct 2016 10:15:39 +0200 Message-ID: <147746973919492@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: copy_up_xattr(): use strnlen 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-copy_up_xattr-use-strnlen.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 8b326c61de08f5ca4bc454a168f19e7e43c4cc2a Mon Sep 17 00:00:00 2001 From: Miklos Szeredi Date: Fri, 16 Sep 2016 14:12:11 +0200 Subject: ovl: copy_up_xattr(): use strnlen From: Miklos Szeredi commit 8b326c61de08f5ca4bc454a168f19e7e43c4cc2a upstream. Be defensive about what underlying fs provides us in the returned xattr list buffer. strlen() may overrun the buffer, so use strnlen() and WARN if the contents are not properly null terminated. Signed-off-by: Miklos Szeredi Signed-off-by: Greg Kroah-Hartman --- fs/overlayfs/copy_up.c | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-) --- a/fs/overlayfs/copy_up.c +++ b/fs/overlayfs/copy_up.c @@ -25,6 +25,7 @@ int ovl_copy_xattr(struct dentry *old, s ssize_t list_size, size, value_size = 0; char *buf, *name, *value = NULL; int uninitialized_var(error); + size_t slen; if (!old->d_inode->i_op->getxattr || !new->d_inode->i_op->getxattr) @@ -47,7 +48,16 @@ int ovl_copy_xattr(struct dentry *old, s goto out; } - for (name = buf; name < (buf + list_size); name += strlen(name) + 1) { + for (name = buf; list_size; name += slen) { + slen = strnlen(name, list_size) + 1; + + /* underlying fs providing us with an broken xattr list? */ + if (WARN_ON(slen > list_size)) { + error = -EIO; + break; + } + list_size -= slen; + if (ovl_is_private_xattr(name)) continue; retry: Patches currently in stable-queue which might be from mszeredi@redhat.com are queue-4.4/ovl-fix-info-leak-in-ovl_lookup_temp.patch queue-4.4/ovl-copy_up_xattr-use-strnlen.patch