From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mout.kundenserver.de (mout.kundenserver.de [217.72.192.75]) by sourceware.org (Postfix) with ESMTPS id 16DE2385800D for ; Thu, 5 Aug 2021 15:07:26 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org 16DE2385800D Received: from calimero.vinschen.de ([24.134.7.25]) by mrelayeu.kundenserver.de (mreue106 [212.227.15.183]) with ESMTPSA (Nemesis) id 1Mqro7-1mxapg2dbl-00msmg for ; Thu, 05 Aug 2021 17:07:25 +0200 Received: by calimero.vinschen.de (Postfix, from userid 500) id ADBA1A80E10; Thu, 5 Aug 2021 17:07:24 +0200 (CEST) Date: Thu, 5 Aug 2021 17:07:24 +0200 From: Corinna Vinschen To: cygwin@cygwin.com Subject: Re: SSHD causes 100% CPU load Message-ID: Reply-To: cygwin@cygwin.com Mail-Followup-To: cygwin@cygwin.com References: <145999495.20210426124252@cfos.de> <1342428656.20210428072302@yandex.ru> <20210805191242.b29a3904cbc4d082bdc3dd37@nifty.ne.jp> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20210805191242.b29a3904cbc4d082bdc3dd37@nifty.ne.jp> X-Provags-ID: V03:K1:pJj2Y8JhGcd9NKZOklW+mxJY9wLNqwYxHZFfjZxPw8zWBF9NbR5 tb51kAZQReH/NIXVRScz9l/kVhU9xz0lccaZSdxXciuF+IL2pQo/rzIoY+G271j61usT7zp eCMxO4CQhgWBntrdbqunMtCYGxdRFEMJaNNmK86+kVIqnkdEkskSM9LE1lGDYytw/OX5rJf e9DsXf3ngrF2FIAngmX2g== X-UI-Out-Filterresults: notjunk:1;V03:K0:MKStRE9bpYI=:0mExfWDN+jvQPNqlZSdfeP nhkUSVSgp/M+nmXIg2Dr6mDFCFISngsM+TbFrzGH7TK10rGHznknhU+Y85FnAd585OFn3L+gG ypEumJbEwIeYcGWFiT0ROpsu8HRVnPpq4tLV/1b7xnHijQBpDKmBRkRWSwUR3ijIb3XOWpOaj RR4wJUVNxJqZk3sy2mQBix26Lotc20RWn1cwTTuCTPSHy85pIo2rwoqpuyeU+b7S2k0rn0b8F QcZ8/1Uc3zGTPpq94IM/g08LZsV6q+rCjuMwm5MyFxWrYHMeiC6/gzb1KHh9G8Cy3x3dZhfRU EYea8Ghind5nIisgTmSfYlCA83ziYyaAqSmGmdnsot4BLABqQ2cvkNRLk1vNdwUSnb3vfy8Me aZ9bLeIqKmFqXjQExmJXagx/opVFBcNgriCgBasoI1AQyOPzHNm8xD9p69DmPIQipBYKZCw2R zsMMJ5Pnenkls9VLAwRiTFKoq/xiV2+6+4L+BIGLTztNFZqyN2qRHLyrrPJZT0xvHztj6QFrs QHnn3/CY8bNmLdZkFp4BN8q86c+imL5RWAe7oOvzlvT/INhGpQ269s8J81q07qcpO48nO9ItF niQzxjk0PW+Z5Xpc1ToWsUUJvkbFVzPB2udAE+9Wvh4z6eIsvzSgdu9OUVWD7lAKNCauZhF0f hxhodlq4JyPbP4KQ1eHcdILnW25vkUriNnYkQH+HFVzlr7vUpbRpy0m5FPefAjuo50Px5wYkP wJY15feOi87tRm4mQ1wXs/eWvim65kGbZY+intF9DPb+nJtqZmPzihqpgNVDqIJOT5vIX5au7 3YNcKpvpXCGLcE4ouffnoc2S+8+mfQb1q9j9py+FJsMVpoft53RUK/rY8uk8oW1qHDVTmkqts x/pyrY2/dA43zEX/3seQ== X-Spam-Status: No, score=-100.2 required=5.0 tests=BAYES_00, GOOD_FROM_CORINNA_CYGWIN, KAM_DMARC_NONE, KAM_DMARC_STATUS, RCVD_IN_DNSWL_NONE, RCVD_IN_MSPIKE_H2, SPF_HELO_NONE, SPF_NEUTRAL, TXREP autolearn=ham autolearn_force=no version=3.4.4 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on server2.sourceware.org X-BeenThere: cygwin@cygwin.com X-Mailman-Version: 2.1.29 Precedence: list List-Id: General Cygwin discussions and problem reports List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 05 Aug 2021 15:07:29 -0000 On Aug 5 19:12, Takashi Yano via Cygwin wrote: > Hi everyone, > > On Wed, 28 Apr 2021 07:23:02 +0300 > Andrey Repin wrote: > > > Greetings, Christoph Lüders! > > > > > I run cygwin 32-bit on Windows 10 Pro Build 19042. Cygwin is 3.2.0-1, > > > openssh is 8.5p1-1. > > > > > I use sshd to access the machine from afar. I notice (often multiple) > > > processes of sshd.exe with 100% CPU load. > > > > https://cygwin.com/pipermail/cygwin/2021-April/248299.html > > https://cygwin.com/pipermail/cygwin/2021-April/248309.html > > > > > A stack shown with procexp has function names like > > > "cygwin1.dll!acl_get_perm" and "cygwin1.dll!_assert". > > > > > Can anyone give me some advice how to proceed further? I have updated > > > to the latest cygwin multiple times; reboot doesn't help either. > > I have finally found how to reproduce this problem in my > environment. The reproduce steps are as follows. > > 1. Install cygwin sshd as a service and start it. > 2. Connect to sshd by 'ssh user@localhost ls' using **Windows** ssh.exe. > 3. Check if sshd remains with high CPU load. > > I have confirmed that this issue happens in a few my PCs. > > Corinna, could you please have a look? Could you perhaps bisect the issue on your machine? The fact that using Windows ssh is an issue makes me wonder if this is some kind of pty problem. The stack info seems fishy to me. sshd doesn't use any ACL functions. Corinna