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=-10.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT 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 8BC50C433DF for ; Thu, 30 Jul 2020 08:12:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 549DB2070B for ; Thu, 30 Jul 2020 08:12:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1596096767; bh=0TS8vaOu8U0C0bL3BfPsJsUIqCQxjQ5c4Kkh2xglFhs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=AYxQidLZfqKcIHxByIHvUj2HwlM2xjVZQoLPL8yLc03kViFM6XN8tyH94MSorb8bH FvTom8pSpD9QQCHy7w+L+7887NuVDAQx3tHPxU/buJWGS1ka0kqSeoAPlXx+foVrF3 JJnhvMnyP8db53Qs8SJ7vGpBvCCMXHesPu0nrqdY= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728980AbgG3IMp (ORCPT ); Thu, 30 Jul 2020 04:12:45 -0400 Received: from mail.kernel.org ([198.145.29.99]:51890 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730063AbgG3IMf (ORCPT ); Thu, 30 Jul 2020 04:12:35 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 87BD52070B; Thu, 30 Jul 2020 08:12:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1596096755; bh=0TS8vaOu8U0C0bL3BfPsJsUIqCQxjQ5c4Kkh2xglFhs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=QPuvJ5MKQpenadQFe5svGsQLk6WpRFMQ95424h9DxYXn/VJsRBxdCqRFm2Mpb19A3 thFus3om5JFVxx7M+GGrd3FUmMTPDpmHuyDVu75EfF1985RqoUN+y210qzX7fjhCi5 ZSEWWLj4waptExhnZoWKuc4xmroTLVabYN7bqXRM= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Peng Fan , Mark Brown Subject: [PATCH 4.4 48/54] regmap: debugfs: check count when read regmap file Date: Thu, 30 Jul 2020 10:05:27 +0200 Message-Id: <20200730074423.496275329@linuxfoundation.org> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20200730074421.203879987@linuxfoundation.org> References: <20200730074421.203879987@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Peng Fan commit 74edd08a4fbf51d65fd8f4c7d8289cd0f392bd91 upstream. When executing the following command, we met kernel dump. dmesg -c > /dev/null; cd /sys; for i in `ls /sys/kernel/debug/regmap/* -d`; do echo "Checking regmap in $i"; cat $i/registers; done && grep -ri "0x02d0" *; It is because the count value is too big, and kmalloc fails. So add an upper bound check to allow max size `PAGE_SIZE << (MAX_ORDER - 1)`. Signed-off-by: Peng Fan Link: https://lore.kernel.org/r/1584064687-12964-1-git-send-email-peng.fan@nxp.com Signed-off-by: Mark Brown Signed-off-by: Greg Kroah-Hartman --- drivers/base/regmap/regmap-debugfs.c | 6 ++++++ 1 file changed, 6 insertions(+) --- a/drivers/base/regmap/regmap-debugfs.c +++ b/drivers/base/regmap/regmap-debugfs.c @@ -194,6 +194,9 @@ static ssize_t regmap_read_debugfs(struc if (*ppos < 0 || !count) return -EINVAL; + if (count > (PAGE_SIZE << (MAX_ORDER - 1))) + count = PAGE_SIZE << (MAX_ORDER - 1); + buf = kmalloc(count, GFP_KERNEL); if (!buf) return -ENOMEM; @@ -342,6 +345,9 @@ static ssize_t regmap_reg_ranges_read_fi if (*ppos < 0 || !count) return -EINVAL; + if (count > (PAGE_SIZE << (MAX_ORDER - 1))) + count = PAGE_SIZE << (MAX_ORDER - 1); + buf = kmalloc(count, GFP_KERNEL); if (!buf) return -ENOMEM;