Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933365AbbDIIyQ (ORCPT ); Thu, 9 Apr 2015 04:54:16 -0400 Received: from mail.kernel.org ([198.145.29.136]:42214 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933304AbbDIIyJ (ORCPT ); Thu, 9 Apr 2015 04:54:09 -0400 From: lizf@kernel.org To: stable@vger.kernel.org Cc: linux-kernel@vger.kernel.org, Sasha Levin , Thomas Gleixner , Ingo Molnar , John Stultz , Zefan Li Subject: [PATCH 3.4 088/176] time: settimeofday: Validate the values of tv from user Date: Thu, 9 Apr 2015 16:45:36 +0800 Message-Id: <1428569224-23820-88-git-send-email-lizf@kernel.org> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1428569028-23762-1-git-send-email-lizf@kernel.org> References: <1428569028-23762-1-git-send-email-lizf@kernel.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2312 Lines: 73 From: Sasha Levin 3.4.107-rc1 review patch. If anyone has any objections, please let me know. ------------------ commit 6ada1fc0e1c4775de0e043e1bd3ae9d065491aa5 upstream. An unvalidated user input is multiplied by a constant, which can result in an undefined behaviour for large values. While this is validated later, we should avoid triggering undefined behaviour. Cc: Thomas Gleixner Cc: Ingo Molnar Signed-off-by: Sasha Levin [jstultz: include trivial milisecond->microsecond correction noticed by Andy] Signed-off-by: John Stultz [lizf: Backported to 3.4: adjust filename] Signed-off-by: Zefan Li --- include/linux/time.h | 13 +++++++++++++ kernel/time.c | 4 ++++ 2 files changed, 17 insertions(+) diff --git a/include/linux/time.h b/include/linux/time.h index 03dce74..bf1bb61 100644 --- a/include/linux/time.h +++ b/include/linux/time.h @@ -189,6 +189,19 @@ extern void getboottime(struct timespec *ts); extern void monotonic_to_bootbased(struct timespec *ts); extern void get_monotonic_boottime(struct timespec *ts); +static inline bool timeval_valid(const struct timeval *tv) +{ + /* Dates before 1970 are bogus */ + if (tv->tv_sec < 0) + return false; + + /* Can't have more microseconds then a second */ + if (tv->tv_usec < 0 || tv->tv_usec >= USEC_PER_SEC) + return false; + + return true; +} + extern struct timespec timespec_trunc(struct timespec t, unsigned gran); extern int timekeeping_valid_for_hres(void); extern u64 timekeeping_max_deferment(void); diff --git a/kernel/time.c b/kernel/time.c index a095290..0864d70 100644 --- a/kernel/time.c +++ b/kernel/time.c @@ -186,6 +186,10 @@ SYSCALL_DEFINE2(settimeofday, struct timeval __user *, tv, if (tv) { if (copy_from_user(&user_tv, tv, sizeof(*tv))) return -EFAULT; + + if (!timeval_valid(&user_tv)) + return -EINVAL; + new_ts.tv_sec = user_tv.tv_sec; new_ts.tv_nsec = user_tv.tv_usec * NSEC_PER_USEC; } -- 1.9.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/