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 iWyPEmdIGVt9SAAAmS7hNA ; Thu, 07 Jun 2018 15:00:14 +0000 Received: by smtp.codeaurora.org (Postfix, from userid 1000) id 759D7608B8; Thu, 7 Jun 2018 15:00:14 +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 CA328606DD; Thu, 7 Jun 2018 15:00:13 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 smtp.codeaurora.org CA328606DD 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 S935790AbeFGPAL (ORCPT + 25 others); Thu, 7 Jun 2018 11:00:11 -0400 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:41327 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S935764AbeFGPAH (ORCPT ); Thu, 7 Jun 2018 11:00:07 -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-0005Zq-P9; Thu, 07 Jun 2018 15:09:40 +0100 Received: from ben by deadeye with local (Exim 4.91) (envelope-from ) id 1fQvb6-00031m-K9; 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, "Michael Kerrisk" , "Kees Cook" , "Mikulas Patocka" , "Eric Biggers" , "Joe Lawrence" , "Willy Tarreau" , "Alexander Viro" , "Luis R . Rodriguez" , "Linus Torvalds" Date: Thu, 07 Jun 2018 15:05:21 +0100 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) Subject: [PATCH 3.16 214/410] pipe: reject F_SETPIPE_SZ with size over UINT_MAX 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 96e99be40e4cff870a83233731121ec0f7f95075 upstream. A pipe's size is represented as an 'unsigned int'. As expected, writing a value greater than UINT_MAX to /proc/sys/fs/pipe-max-size fails with EINVAL. However, the F_SETPIPE_SZ fcntl silently truncates such values to 32 bits, rather than failing with EINVAL as expected. (It *does* fail with EINVAL for values above (1 << 31) but <= UINT_MAX.) Fix this by moving the check against UINT_MAX into round_pipe_size() which is called in both cases. Link: http://lkml.kernel.org/r/20180111052902.14409-6-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 Signed-off-by: Ben Hutchings --- fs/pipe.c | 5 ++++- include/linux/pipe_fs_i.h | 2 +- kernel/sysctl.c | 3 --- 3 files changed, 5 insertions(+), 5 deletions(-) --- a/fs/pipe.c +++ b/fs/pipe.c @@ -1008,10 +1008,13 @@ const struct file_operations pipefifo_fo * Currently we rely on the pipe array holding a power-of-2 number * of pages. Returns 0 on error. */ -unsigned int round_pipe_size(unsigned int size) +unsigned int round_pipe_size(unsigned long size) { unsigned long nr_pages; + if (size > UINT_MAX) + return 0; + /* Minimum pipe size, as required by POSIX */ if (size < PAGE_SIZE) size = PAGE_SIZE; --- a/include/linux/pipe_fs_i.h +++ b/include/linux/pipe_fs_i.h @@ -148,6 +148,6 @@ long pipe_fcntl(struct file *, unsigned struct pipe_inode_info *get_pipe_info(struct file *file); int create_pipe_files(struct file **, int); -unsigned int round_pipe_size(unsigned int size); +unsigned int round_pipe_size(unsigned long size); #endif --- a/kernel/sysctl.c +++ b/kernel/sysctl.c @@ -2230,9 +2230,6 @@ static int do_proc_dopipe_max_size_conv( if (write) { unsigned int val; - if (*lvalp > UINT_MAX) - return -EINVAL; - val = round_pipe_size(*lvalp); if (*negp || val == 0) return -EINVAL;