From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-4.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0C6E8C43218 for ; Sat, 27 Apr 2019 15:29:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D8A1D212F5 for ; Sat, 27 Apr 2019 15:29:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728642AbfD0P3s (ORCPT ); Sat, 27 Apr 2019 11:29:48 -0400 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:32904 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727280AbfD0PPS (ORCPT ); Sat, 27 Apr 2019 11:15:18 -0400 Received: from [192.168.4.242] (helo=deadeye) by shadbolt.decadent.org.uk with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.89) (envelope-from ) id 1hKP2q-0000zO-5B; Sat, 27 Apr 2019 16:15:16 +0100 Received: from ben by deadeye with local (Exim 4.92) (envelope-from ) id 1hKP2m-0004cE-SS; Sat, 27 Apr 2019 16:15:12 +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, Denis Kirjanov , "James Morris" , "Eric Biggers" , "David Howells" Date: Sat, 27 Apr 2019 16:13:09 +0100 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) X-Patchwork-Hint: ignore Subject: [PATCH 3.16 162/202] KEYS: allow reaching the keys quotas exactly In-Reply-To: X-SA-Exim-Connect-IP: 192.168.4.242 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 3.16.66-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Eric Biggers commit a08bf91ce28ed3ae7b6fef35d843fef8dc8c2cd9 upstream. 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") Signed-off-by: Eric Biggers Signed-off-by: David Howells Signed-off-by: James Morris Signed-off-by: Ben Hutchings --- security/keys/key.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) --- a/security/keys/key.c +++ b/security/keys/key.c @@ -260,8 +260,8 @@ struct key *key_alloc(struct key_type *t 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; }