From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Miller Subject: Re: [PATCH v2 net] netlink: Relax attr validation for fixed length types Date: Thu, 07 Dec 2017 14:01:35 -0500 (EST) Message-ID: <20171207.140135.1304328389878622018.davem@davemloft.net> References: <20171207040912.15676-1-dsahern@gmail.com> Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Cc: netdev@vger.kernel.org, johannes@sipsolutions.net To: dsahern@gmail.com Return-path: Received: from shards.monkeyblade.net ([184.105.139.130]:42472 "EHLO shards.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751001AbdLGTBg (ORCPT ); Thu, 7 Dec 2017 14:01:36 -0500 In-Reply-To: <20171207040912.15676-1-dsahern@gmail.com> Sender: netdev-owner@vger.kernel.org List-ID: From: David Ahern Date: Wed, 6 Dec 2017 20:09:12 -0800 > Commit 28033ae4e0f5 ("net: netlink: Update attr validation to require > exact length for some types") requires attributes using types NLA_U* and > NLA_S* to have an exact length. This change is exposing bugs in various > userspace commands that are sending attributes with an invalid length > (e.g., attribute has type NLA_U8 and userspace sends NLA_U32). While > the commands are clearly broken and need to be fixed, users are arguing > that the sudden change in enforcement is breaking older commands on > newer kernels for use cases that otherwise "worked". > > Relax the validation to print a warning mesage similar to what is done > for messages containing extra bytes after parsing. > > Fixes: 28033ae4e0f5 ("net: netlink: Update attr validation to require exact length for some types") > Signed-off-by: David Ahern > Reviewed-by: Johannes Berg > --- > v2 > - updated the comment before nla_attr_len and removed the outdated > comment before use of nla_attr_len Applied and queued up for -stable, thanks David.