From mboxrd@z Thu Jan 1 00:00:00 1970 X-Msuck: nntp://news.gmane.org/gmane.linux.lib.musl.general/13831 Path: news.gmane.org!.POSTED.blaine.gmane.org!not-for-mail From: Rich Felker Newsgroups: gmane.linux.lib.musl.general Subject: Re: __synccall: deadlock and reliance on racy /proc/self/task Date: Wed, 20 Feb 2019 19:41:53 -0500 Message-ID: <20190221004153.GE23599@brightrain.aerifal.cx> References: <1cc54dbe2e4832d804184f33cda0bdd1@ispras.ru> <20190212184849.GO23599@brightrain.aerifal.cx> Reply-To: musl@lists.openwall.com Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Injection-Info: blaine.gmane.org; posting-host="blaine.gmane.org:195.159.176.226"; logging-data="73849"; mail-complaints-to="usenet@blaine.gmane.org" User-Agent: Mutt/1.5.21 (2010-09-15) Cc: musl@lists.openwall.com To: Alexey Izbyshev Original-X-From: musl-return-13847-gllmg-musl=m.gmane.org@lists.openwall.com Thu Feb 21 01:42:17 2019 Return-path: Envelope-to: gllmg-musl@m.gmane.org Original-Received: from mother.openwall.net ([195.42.179.200]) by blaine.gmane.org with smtp (Exim 4.89) (envelope-from ) id 1gwcRL-000J5L-LE for gllmg-musl@m.gmane.org; Thu, 21 Feb 2019 01:42:15 +0100 Original-Received: (qmail 11773 invoked by uid 550); 21 Feb 2019 00:42:13 -0000 Mailing-List: contact musl-help@lists.openwall.com; run by ezmlm Precedence: bulk List-Post: List-Help: List-Unsubscribe: List-Subscribe: List-ID: Original-Received: (qmail 11749 invoked from network); 21 Feb 2019 00:42:11 -0000 Content-Disposition: inline In-Reply-To: <20190212184849.GO23599@brightrain.aerifal.cx> Original-Sender: Rich Felker Xref: news.gmane.org gmane.linux.lib.musl.general:13831 Archived-At: On Tue, Feb 12, 2019 at 01:48:49PM -0500, Rich Felker wrote: > On Sun, Feb 03, 2019 at 12:40:39AM +0300, Alexey Izbyshev wrote: > > Hello! > > > > I've discovered that setuid() deadlocks on a simple stress test > > (attached: test-setuid.c) that creates threads concurrently with > > setuid(). (Tested on 1.1.21 on x86_64, kernel 4.15.x and 4.4.x). The > > gdb output: > > FYI I just posted the start of a new thread describing the possible > thread list design: > > https://www.openwall.com/lists/musl/2019/02/12/14 > > If you want to reply into it the message-id for replies is, > > Message-ID: <20190212182625.GA24199@brightrain.aerifal.cx> > > (still wish the openwall archive showed those...) I believe this issue should be entirely fixed now in git master. When you have time to test, the relevant commits are e4235d70672d9751d7718ddc2b52d0b426430768 and the few leading up to it. Rich