From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932536AbdJJSFB (ORCPT ); Tue, 10 Oct 2017 14:05:01 -0400 Received: from mx1.redhat.com ([209.132.183.28]:33656 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932411AbdJJSE6 (ORCPT ); Tue, 10 Oct 2017 14:04:58 -0400 DMARC-Filter: OpenDMARC Filter v1.3.2 mx1.redhat.com 9940E267C0 Authentication-Results: ext-mx06.extmail.prod.ext.phx2.redhat.com; dmarc=none (p=none dis=none) header.from=redhat.com Authentication-Results: ext-mx06.extmail.prod.ext.phx2.redhat.com; spf=fail smtp.mailfrom=joe.lawrence@redhat.com From: Joe Lawrence To: linux-kernel@vger.kernel.org Cc: Mikulas Patocka , Michael Kerrisk , Randy Dunlap Subject: [PATCH v3 0/4] A few round_pipe_size() and pipe-max-size fixups Date: Tue, 10 Oct 2017 14:04:45 -0400 Message-Id: <1507658689-11669-1-git-send-email-joe.lawrence@redhat.com> X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.30]); Tue, 10 Oct 2017 18:04:58 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org While backporting Michael's "pipe: fix limit handling" patchset to a distro-kernel, Mikulas noticed that current upstream pipe limit handling contains a few problems: 1 - procfs signed wrap: echo'ing a large number into /proc/sys/fs/pipe-max-size and then cat'ing it back out shows a negative value. 2 - round_pipe_size() nr_pages overflow on 32bit: this would subsequently try roundup_pow_of_two(0), which is undefined. 3 - visible non-rounded pipe-max-size value: there is no mutual exclusion or protection between the time pipe_max_size is assigned a raw value from proc_dointvec_minmax() and when it is rounded. 4 - unsigned long -> unsigned int conversion makes for potential odd return errors from do_proc_douintvec_minmax_conv() and do_proc_dopipe_max_size_conv(). This version underwent the same testing as v1: https://marc.info/?l=linux-kernel&m=150643571406022&w=2 v1 (from rfc): - Re-arrange patchset order, push smaller fixes to the front - Add a check so that round_pipe_size(size < pipe_min_size) will round up to round_pipe_size(pipe_min_size) as per man page [RD] - Add new procfs proc_dopipe_max_size() and helpers to consolidate user space read / type validation / rounding / assignment [MP] v2: - Fix !CONFIG_PROC_SYSCTL build case [buildbots] v3: - s/proc_dointvec_minmax/proc_dopipe_max_size/ in comment preceding pipe_proc_fn() - Added a fourth patch to address -ERANGE vs. -EINVAL inconsistencies in do_proc_douintvec_minmax_conv() and do_proc_dopipe_max_size_conv(). Joe Lawrence (4): pipe: match pipe_max_size data type with procfs pipe: avoid round_pipe_size() nr_pages overflow on 32-bit pipe: add proc_dopipe_max_size() to safely assign pipe_max_size sysctl: check for UINT_MAX before unsigned int min/max fs/pipe.c | 23 ++++++++++--------- include/linux/pipe_fs_i.h | 1 + include/linux/sysctl.h | 3 +++ kernel/sysctl.c | 57 ++++++++++++++++++++++++++++++++++++++++++++--- 4 files changed, 70 insertions(+), 14 deletions(-) -- 1.8.3.1