From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756019AbbCBRVY (ORCPT ); Mon, 2 Mar 2015 12:21:24 -0500 Received: from mail-ig0-f171.google.com ([209.85.213.171]:39483 "EHLO mail-ig0-f171.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755596AbbCBRVU (ORCPT ); Mon, 2 Mar 2015 12:21:20 -0500 From: Jeff Vander Stoep To: nnk@google.com Cc: Jeff Vander Stoep , Andrew Morton , Sasha Levin , "Paul E. McKenney" , Rik van Riel , Vlastimil Babka , Paul Cassella , linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: [PATCH] mm: reorder can_do_mlock to fix audit denial Date: Mon, 2 Mar 2015 09:20:32 -0800 Message-Id: <1425316867-6104-1-git-send-email-jeffv@google.com> X-Mailer: git-send-email 2.2.0.rc0.207.ga3a616c Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org A userspace call to mmap(MAP_LOCKED) may result in the successful locking of memory while also producing a confusing audit log denial. can_do_mlock checks capable and rlimit. If either of these return positive can_do_mlock returns true. The capable check leads to an LSM hook used by apparmour and selinux which produce the audit denial. Reordering so rlimit is checked first eliminates the denial on success, only recording a denial when the lock is unsuccessful as a result of the denial. Signed-off-by: Jeff Vander Stoep --- mm/mlock.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/mm/mlock.c b/mm/mlock.c index 73cf098..8a54cd2 100644 --- a/mm/mlock.c +++ b/mm/mlock.c @@ -26,10 +26,10 @@ int can_do_mlock(void) { - if (capable(CAP_IPC_LOCK)) - return 1; if (rlimit(RLIMIT_MEMLOCK) != 0) return 1; + if (capable(CAP_IPC_LOCK)) + return 1; return 0; } EXPORT_SYMBOL(can_do_mlock); -- 2.2.0.rc0.207.ga3a616c