From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1762721AbbA2KhY (ORCPT ); Thu, 29 Jan 2015 05:37:24 -0500 Received: from ip4-83-240-67-251.cust.nbox.cz ([83.240.67.251]:44737 "EHLO ip4-83-240-18-248.cust.nbox.cz" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1755584AbbA2JAU (ORCPT ); Thu, 29 Jan 2015 04:00:20 -0500 From: Jiri Slaby To: stable@vger.kernel.org Cc: linux-kernel@vger.kernel.org, Sasha Levin , Thomas Gleixner , Ingo Molnar , John Stultz , Jiri Slaby Subject: [PATCH 3.12 151/176] time: adjtimex: Validate the ADJ_FREQUENCY values Date: Wed, 28 Jan 2015 15:29:41 +0100 Message-Id: <64678c15381f8efa6beeb565ada1021e45f50c7a.1422455352.git.jslaby@suse.cz> X-Mailer: git-send-email 2.2.2 In-Reply-To: References: In-Reply-To: References: Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Sasha Levin 3.12-stable review patch. If anyone has any objections, please let me know. =============== commit 5e5aeb4367b450a28f447f6d5ab57d8f2ab16a5f upstream. Verify that the frequency value from userspace is valid and makes sense. Unverified values can cause overflows later on. Cc: Thomas Gleixner Cc: Ingo Molnar Signed-off-by: Sasha Levin [jstultz: Fix up bug for negative values and drop redunent cap check] Signed-off-by: John Stultz Signed-off-by: Jiri Slaby --- kernel/time/ntp.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/kernel/time/ntp.c b/kernel/time/ntp.c index af8d1d4f3d55..28db9bedc857 100644 --- a/kernel/time/ntp.c +++ b/kernel/time/ntp.c @@ -631,6 +631,13 @@ int ntp_validate_timex(struct timex *txc) if ((txc->modes & ADJ_SETOFFSET) && (!capable(CAP_SYS_TIME))) return -EPERM; + if (txc->modes & ADJ_FREQUENCY) { + if (LONG_MIN / PPM_SCALE > txc->freq) + return -EINVAL; + if (LONG_MAX / PPM_SCALE < txc->freq) + return -EINVAL; + } + return 0; } -- 2.2.2