From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755192AbcEWN3e (ORCPT ); Mon, 23 May 2016 09:29:34 -0400 Received: from e06smtp13.uk.ibm.com ([195.75.94.109]:48512 "EHLO e06smtp13.uk.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752692AbcEWN3c (ORCPT ); Mon, 23 May 2016 09:29:32 -0400 X-IBM-Helo: d06dlp02.portsmouth.uk.ibm.com X-IBM-MailFrom: schwidefsky@de.ibm.com X-IBM-RcptTo: linux-kernel@vger.kernel.org;linux-s390@vger.kernel.org Date: Mon, 23 May 2016 15:29:21 +0200 From: Martin Schwidefsky To: Michal Hocko Cc: Oleg Nesterov , Aleksa Sarai , LKML , Heiko Carstens , linux-s390@vger.kernel.org, Ingo Molnar , Thomas Gleixner , "H. Peter Anvin" , x86@kernel.org Subject: Re: siginfo memory leak? Message-ID: <20160523152921.11bf49d9@mschwide> In-Reply-To: <20160523130538.GR2278@dhcp22.suse.cz> References: <20160523111630.GN2278@dhcp22.suse.cz> <20160523144319.7579e75f@mschwide> <20160523130538.GR2278@dhcp22.suse.cz> X-Mailer: Claws Mail 3.9.3 (GTK+ 2.24.23; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-TM-AS-MML: disable X-Content-Scanned: Fidelis XPS MAILER x-cbid: 16052313-0013-0000-0000-000014082C2A X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 23 May 2016 15:05:38 +0200 Michal Hocko wrote: > On Mon 23-05-16 14:43:19, Martin Schwidefsky wrote: > > On Mon, 23 May 2016 13:16:30 +0200 > [...] > > > diff --git a/arch/s390/mm/fault.c b/arch/s390/mm/fault.c > > > index 791a4146052c..41913fac14e4 100644 > > > --- a/arch/s390/mm/fault.c > > > +++ b/arch/s390/mm/fault.c > > > @@ -248,6 +248,7 @@ static noinline void do_sigsegv(struct pt_regs *regs, int si_code) > > > si.si_signo = SIGSEGV; > > > si.si_code = si_code; > > > si.si_addr = (void __user *)(regs->int_parm_long & __FAIL_ADDR_MASK); > > > + si.si_errno = 0; > > > force_sig_info(SIGSEGV, &si, current); > > > } > > > > > > > The other for place where s390 calls force_sig_info are correct. > > Only do_sigsegv misses the clear of si_errno. > > I can send a full patch with the proper changelog but I am really > wondering whether we can plug this in a more systematic way. If you > prefer a small s390 specific I will do it right away though. Same > applies to x86 one. Why not fix the bug with a small patch and then provide the "big" solution? A potential information leak is not good .. -- blue skies, Martin. "Reality continues to ruin my life." - Calvin.