From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Cyrus-Session-Id: sloti22d1t05-2179907-1518720285-2-9873847124842886079 X-Sieve: CMU Sieve 3.0 X-Spam-known-sender: no X-Spam-score: 0.0 X-Spam-hits: BAYES_00 -1.9, HEADER_FROM_DIFFERENT_DOMAINS 0.001, ME_NOAUTH 0.01, RCVD_IN_DNSWL_HI -5, T_RP_MATCHES_RCVD -0.01, LANGUAGES en, BAYES_USED global, SA_VERSION 3.4.0 X-Spam-source: IP='209.132.180.67', Host='vger.kernel.org', Country='US', FromHeader='org', MailFrom='org' X-Spam-charsets: plain='UTF-8' X-Resolved-to: greg@kroah.com X-Delivered-to: greg@kroah.com X-Mail-from: stable-owner@vger.kernel.org ARC-Seal: i=1; a=rsa-sha256; cv=none; d=messagingengine.com; s=arctest; t=1518720284; b=jHsAtDLWcLulgka3G5oBGjlnZQkYZxJSiYdJIR/Vy1jlTrS 7nCPP2d44Sf2jVVcdsKlfyUYT1UNovYuI7oGH3rDYgo2GLJCqhV6meMO3xmycNIb +QiSnoYGgnh//ZCNn6R1jcRSGzK7XLkzFD+eSg2qGg9wzXPrCKCzdCrPhmifC5Yo O1yidz+TjGhQ7dVdcRSTiVG2SHhgurhx5Sd8ncYBZl48WX6/u4uYcury/57Ofd1y 0YqDI8diFqH9lHigitVADuEETb9TfcIbMwBHi6YyRPQOOCbmd1jneRG/rQUv4fl1 jdAqdKuDMSxNIGTySWfbmquCLFVIM/QaScGYfjQ== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=from:to:cc:subject:date:message-id :in-reply-to:references:mime-version:content-type:sender :list-id; s=arctest; t=1518720284; bh=nbvXrHZLfDnT1HlWxz1U1Qq6rp EGbd0bG/9ZpkjQb84=; b=nAWyMmCQWMmXnSXn9NbYiaB+hYIhu9DIOqfpdE8JDF 9yVfxNO3PmBpFxaSAOFhyJlx8EoIpY20NNvZOw+ZT0Z8cE9xxIRBkN33gFzK3S4s QjpGzMIjJM/5VtWjz7OugHoO7U/leHv9VkFAt5b2EP9w5yMpwvZ7KnwPvDzUSTeD pidtwI4pzWxQRofbMlj4eCb2urFSqyyhiTn51FDC0doMUoUtYOGp2IXS1C/yqG4a DIbo1LH0WyNMQ7xOCKSzzP5Aj/c758zKioqnSy3oG7oqZKuoLKnAhNYOdMdU1CYt xS+eeZrppeXDrjNRuKM7xZd7kfEtVJRAy7jCmvSmDtNA== ARC-Authentication-Results: i=1; mx1.messagingengine.com; arc=none (no signatures found); dkim=none (no signatures found); dmarc=none (p=none,has-list-id=yes,d=none) header.from=linuxfoundation.org; iprev=pass policy.iprev=209.132.180.67 (vger.kernel.org); spf=none smtp.mailfrom=stable-owner@vger.kernel.org smtp.helo=vger.kernel.org; x-aligned-from=fail; x-ptr=pass x-ptr-helo=vger.kernel.org x-ptr-lookup=vger.kernel.org; x-return-mx=pass smtp.domain=vger.kernel.org smtp.result=pass smtp_org.domain=kernel.org smtp_org.result=pass smtp_is_org_domain=no header.domain=linuxfoundation.org header.result=pass header_is_org_domain=yes Authentication-Results: mx1.messagingengine.com; arc=none (no signatures found); dkim=none (no signatures found); dmarc=none (p=none,has-list-id=yes,d=none) header.from=linuxfoundation.org; iprev=pass policy.iprev=209.132.180.67 (vger.kernel.org); spf=none smtp.mailfrom=stable-owner@vger.kernel.org smtp.helo=vger.kernel.org; x-aligned-from=fail; x-ptr=pass x-ptr-helo=vger.kernel.org x-ptr-lookup=vger.kernel.org; x-return-mx=pass smtp.domain=vger.kernel.org smtp.result=pass smtp_org.domain=kernel.org smtp_org.result=pass smtp_is_org_domain=no header.domain=linuxfoundation.org header.result=pass header_is_org_domain=yes Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1162555AbeBOPXG (ORCPT ); Thu, 15 Feb 2018 10:23:06 -0500 Received: from mail.linuxfoundation.org ([140.211.169.12]:50586 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1161910AbeBOPXE (ORCPT ); Thu, 15 Feb 2018 10:23:04 -0500 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Eric Biggers , Dmitry Vyukov , Alexey Dobriyan , Thomas Gleixner , John Stultz Subject: [PATCH 4.4 047/108] posix-timer: Properly check sigevent->sigev_notify Date: Thu, 15 Feb 2018 16:16:44 +0100 Message-Id: <20180215151228.997834157@linuxfoundation.org> X-Mailer: git-send-email 2.16.1 In-Reply-To: <20180215151222.267507937@linuxfoundation.org> References: <20180215151222.267507937@linuxfoundation.org> User-Agent: quilt/0.65 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: stable-owner@vger.kernel.org X-Mailing-List: stable@vger.kernel.org X-getmail-retrieved-from-mailbox: INBOX X-Mailing-List: linux-kernel@vger.kernel.org List-ID: 4.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Thomas Gleixner commit cef31d9af908243421258f1df35a4a644604efbe upstream. timer_create() specifies via sigevent->sigev_notify the signal delivery for the new timer. The valid modes are SIGEV_NONE, SIGEV_SIGNAL, SIGEV_THREAD and (SIGEV_SIGNAL | SIGEV_THREAD_ID). The sanity check in good_sigevent() is only checking the valid combination for the SIGEV_THREAD_ID bit, i.e. SIGEV_SIGNAL, but if SIGEV_THREAD_ID is not set it accepts any random value. This has no real effects on the posix timer and signal delivery code, but it affects show_timer() which handles the output of /proc/$PID/timers. That function uses a string array to pretty print sigev_notify. The access to that array has no bound checks, so random sigev_notify cause access beyond the array bounds. Add proper checks for the valid notify modes and remove the SIGEV_THREAD_ID masking from various code pathes as SIGEV_NONE can never be set in combination with SIGEV_THREAD_ID. Reported-by: Eric Biggers Reported-by: Dmitry Vyukov Reported-by: Alexey Dobriyan Signed-off-by: Thomas Gleixner Cc: John Stultz Signed-off-by: Greg Kroah-Hartman --- kernel/time/posix-timers.c | 34 +++++++++++++++++++--------------- 1 file changed, 19 insertions(+), 15 deletions(-) --- a/kernel/time/posix-timers.c +++ b/kernel/time/posix-timers.c @@ -507,17 +507,22 @@ static struct pid *good_sigevent(sigeven { struct task_struct *rtn = current->group_leader; - if ((event->sigev_notify & SIGEV_THREAD_ID ) && - (!(rtn = find_task_by_vpid(event->sigev_notify_thread_id)) || - !same_thread_group(rtn, current) || - (event->sigev_notify & ~SIGEV_THREAD_ID) != SIGEV_SIGNAL)) + switch (event->sigev_notify) { + case SIGEV_SIGNAL | SIGEV_THREAD_ID: + rtn = find_task_by_vpid(event->sigev_notify_thread_id); + if (!rtn || !same_thread_group(rtn, current)) + return NULL; + /* FALLTHRU */ + case SIGEV_SIGNAL: + case SIGEV_THREAD: + if (event->sigev_signo <= 0 || event->sigev_signo > SIGRTMAX) + return NULL; + /* FALLTHRU */ + case SIGEV_NONE: + return task_pid(rtn); + default: return NULL; - - if (((event->sigev_notify & ~SIGEV_THREAD_ID) != SIGEV_NONE) && - ((event->sigev_signo <= 0) || (event->sigev_signo > SIGRTMAX))) - return NULL; - - return task_pid(rtn); + } } void posix_timers_register_clock(const clockid_t clock_id, @@ -745,8 +750,7 @@ common_timer_get(struct k_itimer *timr, /* interval timer ? */ if (iv.tv64) cur_setting->it_interval = ktime_to_timespec(iv); - else if (!hrtimer_active(timer) && - (timr->it_sigev_notify & ~SIGEV_THREAD_ID) != SIGEV_NONE) + else if (!hrtimer_active(timer) && timr->it_sigev_notify != SIGEV_NONE) return; now = timer->base->get_time(); @@ -757,7 +761,7 @@ common_timer_get(struct k_itimer *timr, * expiry is > now. */ if (iv.tv64 && (timr->it_requeue_pending & REQUEUE_PENDING || - (timr->it_sigev_notify & ~SIGEV_THREAD_ID) == SIGEV_NONE)) + timr->it_sigev_notify == SIGEV_NONE)) timr->it_overrun += (unsigned int) hrtimer_forward(timer, now, iv); remaining = __hrtimer_expires_remaining_adjusted(timer, now); @@ -767,7 +771,7 @@ common_timer_get(struct k_itimer *timr, * A single shot SIGEV_NONE timer must return 0, when * it is expired ! */ - if ((timr->it_sigev_notify & ~SIGEV_THREAD_ID) != SIGEV_NONE) + if (timr->it_sigev_notify != SIGEV_NONE) cur_setting->it_value.tv_nsec = 1; } else cur_setting->it_value = ktime_to_timespec(remaining); @@ -865,7 +869,7 @@ common_timer_set(struct k_itimer *timr, timr->it.real.interval = timespec_to_ktime(new_setting->it_interval); /* SIGEV_NONE timers are not queued ! See common_timer_get */ - if (((timr->it_sigev_notify & ~SIGEV_THREAD_ID) == SIGEV_NONE)) { + if (timr->it_sigev_notify == SIGEV_NONE) { /* Setup correct expiry time for relative timers */ if (mode == HRTIMER_MODE_REL) { hrtimer_add_expires(timer, timer->base->get_time());