From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-11.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8DD40C3A5A1 for ; Fri, 23 Aug 2019 02:12:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6A89123404 for ; Fri, 23 Aug 2019 02:12:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389467AbfHWCMW (ORCPT ); Thu, 22 Aug 2019 22:12:22 -0400 Received: from Galois.linutronix.de ([193.142.43.55]:33711 "EHLO Galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2389300AbfHWCMS (ORCPT ); Thu, 22 Aug 2019 22:12:18 -0400 Received: from [5.158.153.53] (helo=tip-bot2.lab.linutronix.de) by Galois.linutronix.de with esmtpsa (TLS1.2:DHE_RSA_AES_256_CBC_SHA256:256) (Exim 4.80) (envelope-from ) id 1i0z3n-0000wA-45; Fri, 23 Aug 2019 04:12:15 +0200 Received: from [127.0.1.1] (localhost [IPv6:::1]) by tip-bot2.lab.linutronix.de (Postfix) with ESMTP id C578E1C0883; Fri, 23 Aug 2019 04:12:14 +0200 (CEST) Date: Fri, 23 Aug 2019 02:12:14 -0000 From: tip-bot2 for Thomas Gleixner Reply-to: linux-kernel@vger.kernel.org To: linux-tip-commits@vger.kernel.org Subject: [tip: timers/core] posix-cpu-timers: Sanitize bogus WARNONS Cc: linux-kernel@vger.kernel.org, Frederic Weisbecker , Thomas Gleixner In-Reply-To: <20190819143801.846497772@linutronix.de> References: <20190819143801.846497772@linutronix.de> MIME-Version: 1.0 Message-ID: <156652633476.11645.833680996843703655.tip-bot2@tip-bot2> X-Mailer: tip-git-log-daemon Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails Content-Type: text/plain; charset=utf-8 Content-Disposition: inline X-Linutronix-Spam-Score: -1.0 X-Linutronix-Spam-Level: - X-Linutronix-Spam-Status: No , -1.0 points, 5.0 required, ALL_TRUSTED=-1,SHORTCIRCUIT=-0.0001 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The following commit has been merged into the timers/core branch of tip: Commit-ID: 692117c1f7a6770ed41dd8f277cd9fed1dfb16f1 Gitweb: https://git.kernel.org/tip/692117c1f7a6770ed41dd8f277cd9fed1dfb16f1 Author: Thomas Gleixner AuthorDate: Mon, 19 Aug 2019 16:31:46 +02:00 Committer: Thomas Gleixner CommitterDate: Wed, 21 Aug 2019 20:27:15 +02:00 posix-cpu-timers: Sanitize bogus WARNONS Warning when p == NULL and then proceeding and dereferencing p does not make any sense as the kernel will crash with a NULL pointer dereference right away. Bailing out when p == NULL and returning an error code does not cure the underlying problem which caused p to be NULL. Though it might allow to do proper debugging. Same applies to the clock id check in set_process_cpu_timer(). Clean them up and make them return without trying to do further damage. Signed-off-by: Thomas Gleixner Reviewed-by: Frederic Weisbecker Link: https://lkml.kernel.org/r/20190819143801.846497772@linutronix.de --- kernel/time/posix-cpu-timers.c | 20 +++++++++++++------- 1 file changed, 13 insertions(+), 7 deletions(-) diff --git a/kernel/time/posix-cpu-timers.c b/kernel/time/posix-cpu-timers.c index 742d4a4..98223d2 100644 --- a/kernel/time/posix-cpu-timers.c +++ b/kernel/time/posix-cpu-timers.c @@ -375,7 +375,8 @@ static int posix_cpu_timer_del(struct k_itimer *timer) struct sighand_struct *sighand; struct task_struct *p = timer->it.cpu.task; - WARN_ON_ONCE(p == NULL); + if (WARN_ON_ONCE(!p)) + return -EINVAL; /* * Protect against sighand release/switch in exit/exec and process/ @@ -581,7 +582,8 @@ static int posix_cpu_timer_set(struct k_itimer *timer, int timer_flags, u64 old_expires, new_expires, old_incr, val; int ret; - WARN_ON_ONCE(p == NULL); + if (WARN_ON_ONCE(!p)) + return -EINVAL; /* * Use the to_ktime conversion because that clamps the maximum @@ -716,10 +718,11 @@ static int posix_cpu_timer_set(struct k_itimer *timer, int timer_flags, static void posix_cpu_timer_get(struct k_itimer *timer, struct itimerspec64 *itp) { - u64 now; struct task_struct *p = timer->it.cpu.task; + u64 now; - WARN_ON_ONCE(p == NULL); + if (WARN_ON_ONCE(!p)) + return; /* * Easy part: convert the reload time. @@ -1001,12 +1004,13 @@ static void check_process_timers(struct task_struct *tsk, */ static void posix_cpu_timer_rearm(struct k_itimer *timer) { + struct task_struct *p = timer->it.cpu.task; struct sighand_struct *sighand; unsigned long flags; - struct task_struct *p = timer->it.cpu.task; u64 now; - WARN_ON_ONCE(p == NULL); + if (WARN_ON_ONCE(!p)) + return; /* * Fetch the current sample and update the timer's expiry time. @@ -1203,7 +1207,9 @@ void set_process_cpu_timer(struct task_struct *tsk, unsigned int clock_idx, u64 now; int ret; - WARN_ON_ONCE(clock_idx == CPUCLOCK_SCHED); + if (WARN_ON_ONCE(clock_idx >= CPUCLOCK_SCHED)) + return; + ret = cpu_timer_sample_group(clock_idx, tsk, &now); if (oldval && ret != -EINVAL) {