From patchwork Thu Feb 14 16:20:01 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Howells X-Patchwork-Id: 10813149 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 2D43713B5 for ; Thu, 14 Feb 2019 16:20:18 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 0D6332EBFC for ; Thu, 14 Feb 2019 16:20:18 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 0BB822ECDB; Thu, 14 Feb 2019 16:20:18 +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=-6.9 required=2.0 tests=BAYES_00,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 753232ECFC for ; Thu, 14 Feb 2019 16:20:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388651AbfBNQUG (ORCPT ); Thu, 14 Feb 2019 11:20:06 -0500 Received: from mx1.redhat.com ([209.132.183.28]:64722 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731620AbfBNQUG (ORCPT ); Thu, 14 Feb 2019 11:20:06 -0500 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id EE89F10F8C; Thu, 14 Feb 2019 16:20:05 +0000 (UTC) Received: from warthog.procyon.org.uk (ovpn-121-129.rdu2.redhat.com [10.10.121.129]) by smtp.corp.redhat.com (Postfix) with ESMTP id A9A9660BE3; Thu, 14 Feb 2019 16:20:02 +0000 (UTC) Organization: Red Hat UK Ltd. Registered Address: Red Hat UK Ltd, Amberley Place, 107-111 Peascod Street, Windsor, Berkshire, SI4 1TE, United Kingdom. Registered in England and Wales under Company Registration No. 3798903 Subject: [PATCH 1/4] KEYS: allow reaching the keys quotas exactly From: David Howells To: jmorris@namei.org Cc: linux-security-module@vger.kernel.org, keyrings@vger.kernel.org, dhowells@redhat.com, ebiggers@kernel.org, linux-kernel@vger.kernel.org Date: Thu, 14 Feb 2019 16:20:01 +0000 Message-ID: <155016119453.8115.5525641267104914850.stgit@warthog.procyon.org.uk> In-Reply-To: <155016118572.8115.3243711127043478822.stgit@warthog.procyon.org.uk> References: <155016118572.8115.3243711127043478822.stgit@warthog.procyon.org.uk> User-Agent: StGit/unknown-version MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.28]); Thu, 14 Feb 2019 16:20:06 +0000 (UTC) Sender: owner-linux-security-module@vger.kernel.org Precedence: bulk List-ID: X-Virus-Scanned: ClamAV using ClamSMTP From: Eric Biggers If the sysctl 'kernel.keys.maxkeys' is set to some number n, then actually users can only add up to 'n - 1' keys. Likewise for 'kernel.keys.maxbytes' and the root_* versions of these sysctls. But these sysctls are apparently supposed to be *maximums*, as per their names and all documentation I could find -- the keyrings(7) man page, Documentation/security/keys/core.rst, and all the mentions of EDQUOT meaning that the key quota was *exceeded* (as opposed to reached). Thus, fix the code to allow reaching the quotas exactly. Fixes: 0b77f5bfb45c ("keys: make the keyring quotas controllable through /proc/sys") Cc: stable@vger.kernel.org Signed-off-by: Eric Biggers Signed-off-by: David Howells --- security/keys/key.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/security/keys/key.c b/security/keys/key.c index 44a80d6741a1..0ec9322af4f9 100644 --- a/security/keys/key.c +++ b/security/keys/key.c @@ -265,8 +265,8 @@ struct key *key_alloc(struct key_type *type, const char *desc, spin_lock(&user->lock); if (!(flags & KEY_ALLOC_QUOTA_OVERRUN)) { - if (user->qnkeys + 1 >= maxkeys || - user->qnbytes + quotalen >= maxbytes || + if (user->qnkeys + 1 > maxkeys || + user->qnbytes + quotalen > maxbytes || user->qnbytes + quotalen < user->qnbytes) goto no_quota; }