From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from smtp.codeaurora.org by pdx-caf-mail.web.codeaurora.org (Dovecot) with LMTP id FdtaArZFGVsOJQAAmS7hNA ; Thu, 07 Jun 2018 14:48:39 +0000 Received: by smtp.codeaurora.org (Postfix, from userid 1000) id 2B4C6608C8; Thu, 7 Jun 2018 14:48:39 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on pdx-caf-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI autolearn=ham autolearn_force=no version=3.4.0 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by smtp.codeaurora.org (Postfix) with ESMTP id 69D21601C3; Thu, 7 Jun 2018 14:48:38 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 smtp.codeaurora.org 69D21601C3 Authentication-Results: pdx-caf-mail.web.codeaurora.org; dmarc=none (p=none dis=none) header.from=decadent.org.uk Authentication-Results: pdx-caf-mail.web.codeaurora.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S935113AbeFGOse (ORCPT + 25 others); Thu, 7 Jun 2018 10:48:34 -0400 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:40844 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934471AbeFGOsc (ORCPT ); Thu, 7 Jun 2018 10:48:32 -0400 Received: from [148.252.241.226] (helo=deadeye) by shadbolt.decadent.org.uk with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.84_2) (envelope-from ) id 1fQvbg-0005Zw-Eq; Thu, 07 Jun 2018 15:09:40 +0100 Received: from ben by deadeye with local (Exim 4.91) (envelope-from ) id 1fQvb6-00031P-DO; Thu, 07 Jun 2018 15:09:04 +0100 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, "Linus Torvalds" , "Luis R . Rodriguez" , "Eric Biggers" , "Mikulas Patocka" , "Willy Tarreau" , "Alexander Viro" , "Joe Lawrence" , "Michael Kerrisk" , "Kees Cook" Date: Thu, 07 Jun 2018 15:05:21 +0100 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) Subject: [PATCH 3.16 210/410] pipe, sysctl: drop 'min' parameter from pipe-max-size converter In-Reply-To: X-SA-Exim-Connect-IP: 148.252.241.226 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.16.57-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Eric Biggers commit 4c2e4befb3cc9ce42d506aa537c9ab504723e98c upstream. Patch series "pipe: buffer limits fixes and cleanups", v2. This series simplifies the sysctl handler for pipe-max-size and fixes another set of bugs related to the pipe buffer limits: - The root user wasn't allowed to exceed the limits when creating new pipes. - There was an off-by-one error when checking the limits, so a limit of N was actually treated as N - 1. - F_SETPIPE_SZ accepted values over UINT_MAX. - Reading the pipe buffer limits could be racy. This patch (of 7): Before validating the given value against pipe_min_size, do_proc_dopipe_max_size_conv() calls round_pipe_size(), which rounds the value up to pipe_min_size. Therefore, the second check against pipe_min_size is redundant. Remove it. Link: http://lkml.kernel.org/r/20180111052902.14409-2-ebiggers3@gmail.com Signed-off-by: Eric Biggers Acked-by: Kees Cook Acked-by: Joe Lawrence Cc: Alexander Viro Cc: "Luis R . Rodriguez" Cc: Michael Kerrisk Cc: Mikulas Patocka Cc: Willy Tarreau Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds [bwh: Backported to 3.16: adjust context] Signed-off-by: Ben Hutchings --- fs/pipe.c | 10 +++------- include/linux/pipe_fs_i.h | 2 +- kernel/sysctl.c | 15 +-------------- 3 files changed, 5 insertions(+), 22 deletions(-) --- a/fs/pipe.c +++ b/fs/pipe.c @@ -34,11 +34,6 @@ */ unsigned int pipe_max_size = 1048576; -/* - * Minimum pipe size, as required by POSIX - */ -unsigned int pipe_min_size = PAGE_SIZE; - /* Maximum allocatable pages per user. Hard limit is unset by default, soft * matches default values. */ @@ -1012,8 +1007,9 @@ unsigned int round_pipe_size(unsigned in { unsigned long nr_pages; - if (size < pipe_min_size) - size = pipe_min_size; + /* Minimum pipe size, as required by POSIX */ + if (size < PAGE_SIZE) + size = PAGE_SIZE; nr_pages = (size + PAGE_SIZE - 1) >> PAGE_SHIFT; if (nr_pages == 0) --- a/include/linux/pipe_fs_i.h +++ b/include/linux/pipe_fs_i.h @@ -124,7 +124,7 @@ void pipe_lock(struct pipe_inode_info *) void pipe_unlock(struct pipe_inode_info *); void pipe_double_lock(struct pipe_inode_info *, struct pipe_inode_info *); -extern unsigned int pipe_max_size, pipe_min_size; +extern unsigned int pipe_max_size; extern unsigned long pipe_user_pages_hard; extern unsigned long pipe_user_pages_soft; int pipe_proc_fn(struct ctl_table *, int, void __user *, size_t *, loff_t *); --- a/kernel/sysctl.c +++ b/kernel/sysctl.c @@ -1672,7 +1672,6 @@ static struct ctl_table fs_table[] = { .maxlen = sizeof(int), .mode = 0644, .proc_handler = &pipe_proc_fn, - .extra1 = &pipe_min_size, }, { .procname = "pipe-user-pages-hard", @@ -2223,15 +2222,9 @@ int proc_dointvec_minmax(struct ctl_tabl do_proc_dointvec_minmax_conv, ¶m); } -struct do_proc_dopipe_max_size_conv_param { - unsigned int *min; -}; - static int do_proc_dopipe_max_size_conv(bool *negp, unsigned long *lvalp, int *valp, int write, void *data) { - struct do_proc_dopipe_max_size_conv_param *param = data; - if (write) { unsigned int val; @@ -2242,9 +2235,6 @@ static int do_proc_dopipe_max_size_conv( if (*negp || val == 0) return -EINVAL; - if (param->min && *param->min > val) - return -ERANGE; - *valp = val; } else { unsigned int val = *valp; @@ -2258,11 +2248,8 @@ static int do_proc_dopipe_max_size_conv( int proc_dopipe_max_size(struct ctl_table *table, int write, void __user *buffer, size_t *lenp, loff_t *ppos) { - struct do_proc_dopipe_max_size_conv_param param = { - .min = (unsigned int *) table->extra1, - }; return do_proc_dointvec(table, write, buffer, lenp, ppos, - do_proc_dopipe_max_size_conv, ¶m); + do_proc_dopipe_max_size_conv, NULL); } static void validate_coredump_safety(void)