From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934608AbdBQPUk (ORCPT ); Fri, 17 Feb 2017 10:20:40 -0500 Received: from smtp.nsa.gov ([8.44.101.8]:19937 "EHLO emsm-gh1-uea10.nsa.gov" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934159AbdBQPUg (ORCPT ); Fri, 17 Feb 2017 10:20:36 -0500 X-Greylist: delayed 590 seconds by postgrey-1.27 at vger.kernel.org; Fri, 17 Feb 2017 10:20:36 EST X-IronPort-AV: E=Sophos;i="5.35,172,1484006400"; d="scan'208";a="3997600" IronPort-PHdr: =?us-ascii?q?9a23=3ASN9zxxa3VXW/XXPvhP8xdMH/LSx+4OfEezUN459i?= =?us-ascii?q?sYplN5qZr8SzbnLW6fgltlLVR4KTs6sC0LuL9fi+EjNbqb+681k6OKRWUBEEjc?= =?us-ascii?q?hE1ycBO+WiTXPBEfjxciYhF95DXlI2t1uyMExSBdqsLwaK+i764jEdAAjwOhRo?= =?us-ascii?q?LerpBIHSk9631+ev8JHPfglEnjSwbLdyIRmssQnct8YajIlsJ60s1hbHv3xEdv?= =?us-ascii?q?hMy2h1P1yThRH85smx/J5n7Stdvu8q+tBDX6vnYak2VKRUAzs6PW874s3rrgTD?= =?us-ascii?q?QhCU5nQASGUWkwFHDBbD4RrnQ5r+qCr6tu562CmHIc37SK0/VDq+46t3ThLjlS?= =?us-ascii?q?kINyQ98GrKlMJ+iqxVqw+lqxBm3YLYfISZOfxjda3fYNwaX3JMUMZPWSJcDI2y?= =?us-ascii?q?bIwBAvEdMepEtYTxu0EDoQeiCQSqGejhyiVIhnjz3aAizuohDR/J3BQgH90Qtn?= =?us-ascii?q?Tfscj7NKIIXuCxyKnH0zXCZO5R1Dfm9YfIaQssoe2MXL1sccrRzlMjFwXejlqK?= =?us-ascii?q?s4DlMDSV1voUvmWd8uFuVvqvhnY6pwx+rTWj3MchhpTTio4LxV3I6z91zJszKN?= =?us-ascii?q?alUkB0e8SkH4FVtyyCMot2Rd4tTH9wtSYhz70GpYa7fC8XyJQ73xLfa+KIc4yP?= =?us-ascii?q?4h/7SOaeOy14hHN4eLKknRqy7UihxfH8VsmzylpKqDZKksLQuXwX0hzT68yHRu?= =?us-ascii?q?N8/kenxzmPyxje5vxLLE07j6bWK4MtzqQumpccr0jPBDL6lF3zjKCMd0Uk/uao?= =?us-ascii?q?6/7gYrXjvpKcLJJ7ihrlP6Qyms2wHeQ4Mg8UU2id4uSzzqfv/UL+QLVUlvE2iL?= =?us-ascii?q?XWsIjGJcQHoa60GwtV0ocl6xaiADaqyc8YkmcbI1JYYhKHjpTpOlHXLPD9Cvew?= =?us-ascii?q?nkmskDN1yP3dIL3hDYvCLmLZnLfiY7l98UhcxxQ3zdxF4JJUEL4BKurpWkDtrN?= =?us-ascii?q?zYEgM5MwuszubjCdV90J4eWG2WDq+aLqzSq1mI6fwrI+SXeo8VtyjyK+I/6/7t?= =?us-ascii?q?k3A5g1kdcret3ZcNb3C4BPtmKV2DYXXwmtcBDXsKvg0mQez2h12CVTFSam22X6?= =?us-ascii?q?I94DE7FZ6mDZ3ERoCrgbyA0z23EYBIaTMONlfZDXjsZ62AWvERdDiVJM5x1DAJ?= =?us-ascii?q?Bpa7TIp07g2jrA/3zfJcK+PQ/iAJ/cb42MNd+/zYlRZ08yd9ScuazTfeHClPgm?= =?us-ascii?q?oUSmpuj+hEqktnxwLGi/B1?= X-IPAS-Result: =?us-ascii?q?A2GMBADuEadY/wHyM5BeGwEBAQMBAQEJAQEBFgEBAQMBAQE?= =?us-ascii?q?JAQEBgyaBap5IAQEBAQEBBpRHhBsahgiCIVcBAQEBAQEBAQIBAl8ogjMigklSK?= =?us-ascii?q?IEpiV8NslQ6JgKLLzKGB4pUggAMgw0FkEWLPIoSiAcCilSGMAJIklZYgQAZBwI?= =?us-ascii?q?SCBsPhx8iNYprAQEB?= From: Stephen Smalley To: tglx@linutronix.de Cc: linux-kernel@vger.kernel.org, linux-security-module@vger.kernel.org, selinux@tycho.nsa.gov, Stephen Smalley Subject: [PATCH] timerfd: only check CAP_WAKE_ALARM when it is needed Date: Fri, 17 Feb 2017 10:13:59 -0500 Message-Id: <1487344439-22293-1-git-send-email-sds@tycho.nsa.gov> X-Mailer: git-send-email 2.7.4 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org timerfd_create() and do_timerfd_settime() presently always call capable(CAP_WAKE_ALARM) although CAP_WAKE_ALARM is only required for CLOCK_REALTIME_ALARM and CLOCK_BOOTTIME_ALARM. This can cause extraneous audit messages when using a LSM such as SELinux, incorrectly causes PF_SUPERPRIV to be set even when no privilege was exercised, and is inefficient. Flip the order of the tests in both functions so that we only call capable() if the capability is truly required for the operation. Signed-off-by: Stephen Smalley --- fs/timerfd.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/fs/timerfd.c b/fs/timerfd.c index 384fa75..c543cdb 100644 --- a/fs/timerfd.c +++ b/fs/timerfd.c @@ -400,9 +400,9 @@ SYSCALL_DEFINE2(timerfd_create, int, clockid, int, flags) clockid != CLOCK_BOOTTIME_ALARM)) return -EINVAL; - if (!capable(CAP_WAKE_ALARM) && - (clockid == CLOCK_REALTIME_ALARM || - clockid == CLOCK_BOOTTIME_ALARM)) + if ((clockid == CLOCK_REALTIME_ALARM || + clockid == CLOCK_BOOTTIME_ALARM) && + !capable(CAP_WAKE_ALARM)) return -EPERM; ctx = kzalloc(sizeof(*ctx), GFP_KERNEL); @@ -449,7 +449,7 @@ static int do_timerfd_settime(int ufd, int flags, return ret; ctx = f.file->private_data; - if (!capable(CAP_WAKE_ALARM) && isalarm(ctx)) { + if (isalarm(ctx) && !capable(CAP_WAKE_ALARM)) { fdput(f); return -EPERM; } -- 2.7.4