From owner-freebsd-hackers Mon Sep 17 14:15:43 2001 Delivered-To: freebsd-hackers@freebsd.org Received: from elvis.mu.org (elvis.mu.org [216.33.66.196]) by hub.freebsd.org (Postfix) with ESMTP id 5B23F37B407 for ; Mon, 17 Sep 2001 14:15:40 -0700 (PDT) Received: by elvis.mu.org (Postfix, from userid 1192) id 2358481D09; Mon, 17 Sep 2001 16:15:40 -0500 (CDT) Date: Mon, 17 Sep 2001 16:15:40 -0500 From: Alfred Perlstein To: Matt Dillon Cc: hackers@FreeBSD.org Subject: Re: bug in sshd - signal during free() Message-ID: <20010917161540.A968@elvis.mu.org> References: <200109172032.f8HKW6M41638@earth.backplane.com> <20010917160103.Z968@elvis.mu.org> <200109172104.f8HL45641959@earth.backplane.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.2.5i In-Reply-To: <200109172104.f8HL45641959@earth.backplane.com>; from dillon@earth.backplane.com on Mon, Sep 17, 2001 at 02:04:05PM -0700 Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.ORG * Matt Dillon [010917 16:04] wrote: > > : > :* Matt Dillon [010917 15:32] wrote: > :> sshd died on one of our machines today. The traceback seems to > :> indicate that a signal is interrupting a free(). I'm going to > :> play with the code a bit to see if there's an easy fix. > :> > :> This bug can't occur very often... the key regeneration signal > :> has to occur *just* as sshd is trying to free() something. > : > :The bug seems more likely to be caused by use of unsafe functions > :in a signal handler. > : > :I'm really suprised that the OpenSSH team didn't slap whomever decided > :to do so much processing within a signal handler silly. > > It's funny... they had an XXX comment in there so obviously someone > was a little jittery about it. I think they just didn't realize that > a malloc() might occur inside the signal handler or they would have > fixed it long ago. > > UNIX signals suck. Any async notification would require the same amount of care. Most programmers suck. :) -- -Alfred Perlstein [alfred@freebsd.org] 'Instead of asking why a piece of software is using "1970s technology," start asking why software is ignoring 30 years of accumulated wisdom.' To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message