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=-16.6 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable 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 DFA6AC49EA5 for ; Mon, 21 Jun 2021 16:29:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C374F611C1 for ; Mon, 21 Jun 2021 16:29:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232047AbhFUQbp (ORCPT ); Mon, 21 Jun 2021 12:31:45 -0400 Received: from mail.kernel.org ([198.145.29.99]:48302 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230357AbhFUQ1z (ORCPT ); Mon, 21 Jun 2021 12:27:55 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 32B4A613EB; Mon, 21 Jun 2021 16:23:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1624292584; bh=mylEgiwtRkEGqF1+6jEvX8z7gkdV3zCUBmhzGEtZKFc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=VY27cdmXPw9/WP2I9wj+4AhN1scZJwC7U5Q0jG8hF2aaFMi+hWOOgOxwfsKnE/jVz RhspOyg4yZFi0/VYU8AHYktj9Om+k3J5kkvPba/JV7sIjI0voa+EP98iAh7DjaR4j2 GFTlYbkhK5MHqjCXG2F1MpoWZYHFdYnbsT2u4iF8= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Jakub Kicinski , Richard Cochran , "David S. Miller" , Sasha Levin Subject: [PATCH 5.10 055/146] ptp: improve max_adj check against unreasonable values Date: Mon, 21 Jun 2021 18:14:45 +0200 Message-Id: <20210621154913.983787719@linuxfoundation.org> X-Mailer: git-send-email 2.32.0 In-Reply-To: <20210621154911.244649123@linuxfoundation.org> References: <20210621154911.244649123@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Jakub Kicinski [ Upstream commit 475b92f932168a78da8109acd10bfb7578b8f2bb ] Scaled PPM conversion to PPB may (on 64bit systems) result in a value larger than s32 can hold (freq/scaled_ppm is a long). This means the kernel will not correctly reject unreasonably high ->freq values (e.g. > 4294967295ppb, 281474976645 scaled PPM). The conversion is equivalent to a division by ~66 (65.536), so the value of ppb is always smaller than ppm, but not small enough to assume narrowing the type from long -> s32 is okay. Note that reasonable user space (e.g. ptp4l) will not use such high values, anyway, 4289046510ppb ~= 4.3x, so the fix is somewhat pedantic. Fixes: d39a743511cd ("ptp: validate the requested frequency adjustment.") Fixes: d94ba80ebbea ("ptp: Added a brand new class driver for ptp clocks.") Signed-off-by: Jakub Kicinski Acked-by: Richard Cochran Signed-off-by: David S. Miller Signed-off-by: Sasha Levin --- drivers/ptp/ptp_clock.c | 6 +++--- include/linux/ptp_clock_kernel.h | 2 +- 2 files changed, 4 insertions(+), 4 deletions(-) diff --git a/drivers/ptp/ptp_clock.c b/drivers/ptp/ptp_clock.c index 03a246e60fd9..21c4c34c52d8 100644 --- a/drivers/ptp/ptp_clock.c +++ b/drivers/ptp/ptp_clock.c @@ -63,7 +63,7 @@ static void enqueue_external_timestamp(struct timestamp_event_queue *queue, spin_unlock_irqrestore(&queue->lock, flags); } -s32 scaled_ppm_to_ppb(long ppm) +long scaled_ppm_to_ppb(long ppm) { /* * The 'freq' field in the 'struct timex' is in parts per @@ -80,7 +80,7 @@ s32 scaled_ppm_to_ppb(long ppm) s64 ppb = 1 + ppm; ppb *= 125; ppb >>= 13; - return (s32) ppb; + return (long) ppb; } EXPORT_SYMBOL(scaled_ppm_to_ppb); @@ -138,7 +138,7 @@ static int ptp_clock_adjtime(struct posix_clock *pc, struct __kernel_timex *tx) delta = ktime_to_ns(kt); err = ops->adjtime(ops, delta); } else if (tx->modes & ADJ_FREQUENCY) { - s32 ppb = scaled_ppm_to_ppb(tx->freq); + long ppb = scaled_ppm_to_ppb(tx->freq); if (ppb > ops->max_adj || ppb < -ops->max_adj) return -ERANGE; if (ops->adjfine) diff --git a/include/linux/ptp_clock_kernel.h b/include/linux/ptp_clock_kernel.h index d3e8ba5c7125..6d6b42143eff 100644 --- a/include/linux/ptp_clock_kernel.h +++ b/include/linux/ptp_clock_kernel.h @@ -222,7 +222,7 @@ extern int ptp_clock_index(struct ptp_clock *ptp); * @ppm: Parts per million, but with a 16 bit binary fractional field */ -extern s32 scaled_ppm_to_ppb(long ppm); +extern long scaled_ppm_to_ppb(long ppm); /** * ptp_find_pin() - obtain the pin index of a given auxiliary function -- 2.30.2