From patchwork Fri Sep 7 20:28:54 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Waiman Long X-Patchwork-Id: 10592539 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 9B8986CB for ; Fri, 7 Sep 2018 20:29:50 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 8ED352B932 for ; Fri, 7 Sep 2018 20:29:50 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 829C42B954; Fri, 7 Sep 2018 20:29:50 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 2A1F02B932 for ; Fri, 7 Sep 2018 20:29:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726665AbeIHBLs (ORCPT ); Fri, 7 Sep 2018 21:11:48 -0400 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:45406 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726089AbeIHBLr (ORCPT ); Fri, 7 Sep 2018 21:11:47 -0400 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.rdu2.redhat.com [10.11.54.4]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 8B99087A87; Fri, 7 Sep 2018 20:29:11 +0000 (UTC) Received: from llong.com (dhcp-17-8.bos.redhat.com [10.18.17.8]) by smtp.corp.redhat.com (Postfix) with ESMTP id 359912027EB7; Fri, 7 Sep 2018 20:29:11 +0000 (UTC) From: Waiman Long To: "Luis R. Rodriguez" , Kees Cook , Andrew Morton , Jonathan Corbet Cc: linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-doc@vger.kernel.org, Al Viro , Matthew Wilcox , "Eric W. Biederman" , Takashi Iwai , Davidlohr Bueso , Waiman Long Subject: [PATCH v9 1/4] ipc: IPCMNI limit check for msgmni and shmmni Date: Fri, 7 Sep 2018 16:28:54 -0400 Message-Id: <1536352137-12003-2-git-send-email-longman@redhat.com> In-Reply-To: <1536352137-12003-1-git-send-email-longman@redhat.com> References: <1536352137-12003-1-git-send-email-longman@redhat.com> X-Scanned-By: MIMEDefang 2.78 on 10.11.54.4 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.1]); Fri, 07 Sep 2018 20:29:11 +0000 (UTC) X-Greylist: inspected by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.1]); Fri, 07 Sep 2018 20:29:11 +0000 (UTC) for IP:'10.11.54.4' DOMAIN:'int-mx04.intmail.prod.int.rdu2.redhat.com' HELO:'smtp.corp.redhat.com' FROM:'longman@redhat.com' RCPT:'' Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP A user can write arbitrary integer values to msgmni and shmmni sysctl parameters without getting error, but the actual limit is really IPCMNI (32k). This can mislead users as they think they can get a value that is not real. The right limits are now set for msgmni and shmmni so that the users will become aware if they set a value outside of the acceptable range. Signed-off-by: Waiman Long Acked-by: Luis R. Rodriguez Reviewed-by: Davidlohr Bueso --- ipc/ipc_sysctl.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/ipc/ipc_sysctl.c b/ipc/ipc_sysctl.c index 8ad93c2..f87cb29 100644 --- a/ipc/ipc_sysctl.c +++ b/ipc/ipc_sysctl.c @@ -99,6 +99,7 @@ static int proc_ipc_auto_msgmni(struct ctl_table *table, int write, static int zero; static int one = 1; static int int_max = INT_MAX; +static int ipc_mni = IPCMNI; static struct ctl_table ipc_kern_table[] = { { @@ -120,7 +121,9 @@ static int proc_ipc_auto_msgmni(struct ctl_table *table, int write, .data = &init_ipc_ns.shm_ctlmni, .maxlen = sizeof(init_ipc_ns.shm_ctlmni), .mode = 0644, - .proc_handler = proc_ipc_dointvec, + .proc_handler = proc_ipc_dointvec_minmax, + .extra1 = &zero, + .extra2 = &ipc_mni, }, { .procname = "shm_rmid_forced", @@ -147,7 +150,7 @@ static int proc_ipc_auto_msgmni(struct ctl_table *table, int write, .mode = 0644, .proc_handler = proc_ipc_dointvec_minmax, .extra1 = &zero, - .extra2 = &int_max, + .extra2 = &ipc_mni, }, { .procname = "auto_msgmni",