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=-18.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,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 DB83BC433E6 for ; Mon, 1 Mar 2021 18:22:40 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9345364F7C for ; Mon, 1 Mar 2021 18:22:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239638AbhCASWX (ORCPT ); Mon, 1 Mar 2021 13:22:23 -0500 Received: from mail.kernel.org ([198.145.29.99]:35642 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S239542AbhCASRA (ORCPT ); Mon, 1 Mar 2021 13:17:00 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id 8F533650CF; Mon, 1 Mar 2021 17:44:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1614620655; bh=f9NRaC5Oh62uXWYTZTMNKQcmTsrA5jD5yC9ZKfyJqik=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Tn2rA91sJ/bCaPF8wGlD9cy0BHKD41opmc/hMG1qnccn7pCnVogMTelbtldMidq7e Kg9Xf4jXa3LJkM7oW7vWIZnTY4S+2SJBbo0SZyu1ss0d+V1reQs19Iu6w+1BIYGtPN EAFWbZD3288gB1K9oxSlRB3w4ASaArD3/h3ysEMY= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, yangerkun , Miquel Raynal , Sasha Levin Subject: [PATCH 5.11 230/775] mtd: phram: use div_u64_rem to stop overwrite len in phram_setup Date: Mon, 1 Mar 2021 17:06:38 +0100 Message-Id: <20210301161212.995927005@linuxfoundation.org> X-Mailer: git-send-email 2.30.1 In-Reply-To: <20210301161201.679371205@linuxfoundation.org> References: <20210301161201.679371205@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: stable@vger.kernel.org From: yangerkun [ Upstream commit dc2b3e5cbc8087224fcd8698b0dc56131e0bf37d ] We now support user to set erase page size, and use do_div between len and erase size to determine the reasonableness for the erase size. However, do_div is a macro and will overwrite the value of len. Which results a mtd device with unexcepted size. Fix it by use div_u64_rem. Fixes: ffad560394de ("mtd: phram: Allow the user to set the erase page size.") Signed-off-by: yangerkun Signed-off-by: Miquel Raynal Link: https://lore.kernel.org/linux-mtd/20210125124936.651812-1-yangerkun@huawei.com Signed-off-by: Sasha Levin --- drivers/mtd/devices/phram.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/drivers/mtd/devices/phram.c b/drivers/mtd/devices/phram.c index cfd170946ba48..5b04ae6c30573 100644 --- a/drivers/mtd/devices/phram.c +++ b/drivers/mtd/devices/phram.c @@ -222,6 +222,7 @@ static int phram_setup(const char *val) uint64_t start; uint64_t len; uint64_t erasesize = PAGE_SIZE; + uint32_t rem; int i, ret; if (strnlen(val, sizeof(buf)) >= sizeof(buf)) @@ -263,8 +264,11 @@ static int phram_setup(const char *val) } } + if (erasesize) + div_u64_rem(len, (uint32_t)erasesize, &rem); + if (len == 0 || erasesize == 0 || erasesize > len - || erasesize > UINT_MAX || do_div(len, (uint32_t)erasesize) != 0) { + || erasesize > UINT_MAX || rem) { parse_err("illegal erasesize or len\n"); goto error; } -- 2.27.0