From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Thomas Gleixner , Ingo Molnar , Sasha Levin , John Stultz Subject: [PATCH 3.14 17/77] time: adjtimex: Validate the ADJ_FREQUENCY values Date: Tue, 27 Jan 2015 17:26:55 -0800 Message-Id: <20150128012746.480339545@linuxfoundation.org> In-Reply-To: <20150128012745.971137091@linuxfoundation.org> References: <20150128012745.971137091@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: 3.14-stable review patch. If anyone has any objections, please let me know. ------------------ From: Sasha Levin 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: Greg Kroah-Hartman --- kernel/time/ntp.c | 7 +++++++ 1 file changed, 7 insertions(+) --- 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; }