From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Message-ID: <1494331983.3965.5.camel@codethink.co.uk> Subject: Re: [PATCH 4.4 06/28] cifs: Do not send echoes before Negotiate is complete From: Ben Hutchings To: Sachin Prabhu , Pavel Shilovsky , Steve French Cc: linux-kernel@vger.kernel.org, stable@vger.kernel.org, Jonathan Liu , Greg Kroah-Hartman Date: Tue, 09 May 2017 13:13:03 +0100 In-Reply-To: <20170425150814.983340482@linuxfoundation.org> References: <20170425150814.719042460@linuxfoundation.org> <20170425150814.983340482@linuxfoundation.org> Content-Type: text/plain; charset="UTF-8" Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: On Tue, 2017-04-25 at 16:08 +0100, Greg Kroah-Hartman wrote: > 4.4-stable review patch. If anyone has any objections, please let me know. > > ------------------ > > From: Sachin Prabhu > > commit 62a6cfddcc0a5313e7da3e8311ba16226fe0ac10 upstream. > > commit 4fcd1813e640 ("Fix reconnect to not defer smb3 session reconnect > long after socket reconnect") added support for Negotiate requests to > be initiated by echo calls. > > To avoid delays in calling echo after a reconnect, I added the patch > introduced by the commit b8c600120fc8 ("Call echo service immediately > after socket reconnect"). The second commit hasn't actually been applied to any stable branches (so this one didn't need to be). Should it be? Ben. > This has however caused a regression with cifs shares which do not have > support for echo calls to trigger Negotiate requests. On connections > which need to call Negotiation, the echo calls trigger an error which > triggers a reconnect which in turn triggers another echo call. This > results in a loop which is only broken when an operation is performed on > the cifs share. For an idle share, it can DOS a server. [...] -- Ben Hutchings Software Developer, Codethink Ltd.