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=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,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 B4DC1C433E0 for ; Tue, 23 Jun 2020 20:29:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9240D2070E for ; Tue, 23 Jun 2020 20:29:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1592944189; bh=0PBbNoMLgT/OjPeh5DapmIdaNhEuA8/SPN2ldUn2pTo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=Sdu5WgcdXiFpOwkMUS5vb8I81ukLvbR3nq/U6gmLM37VXN9RGqYAS66YFhffnUla7 fXdEyrwiuxrh0OjgeyoLohbngpwqZY3QNiyZvVU6oikpl6doWAK/54lnxKAUn+BPs0 97AX7wkQO3pmkQLefus2e1D5dnBbJ/y6eYoIhkB4= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2391024AbgFWU3s (ORCPT ); Tue, 23 Jun 2020 16:29:48 -0400 Received: from mail.kernel.org ([198.145.29.99]:49680 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2391002AbgFWU3g (ORCPT ); Tue, 23 Jun 2020 16:29:36 -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 EB91B206C3; Tue, 23 Jun 2020 20:29:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1592944176; bh=0PBbNoMLgT/OjPeh5DapmIdaNhEuA8/SPN2ldUn2pTo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=0FbmZVfbouu+tHvTidLWoUCHDn6W9hMzkBlB8YvX4etHJLa0NVKguohks0mc2+ARU AlUP5Wjq60CZRRCaWV0AWuORDC/aphx1AeoUtdGQN64UA7r/GXHqbIdv8H7zkRbxmJ JXtaUXk+11ToamAa2kK7kw0vMO89US5y1xRlXK4Y= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Derek Kiernan , Dragan Cvetic , Arnd Bergmann , Michal Simek , linux-arm-kernel@lists.infradead.org, John Hubbard , Sasha Levin Subject: [PATCH 5.4 195/314] misc: xilinx-sdfec: improve get_user_pages_fast() error handling Date: Tue, 23 Jun 2020 21:56:30 +0200 Message-Id: <20200623195348.226110468@linuxfoundation.org> X-Mailer: git-send-email 2.27.0 In-Reply-To: <20200623195338.770401005@linuxfoundation.org> References: <20200623195338.770401005@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: John Hubbard [ Upstream commit 57343d51613227373759f5b0f2eede257fd4b82e ] This fixes the case of get_user_pages_fast() returning a -errno. The result needs to be stored in a signed integer. And for safe signed/unsigned comparisons, it's best to keep everything signed. And get_user_pages_fast() also expects a signed value for number of pages to pin. Therefore, change most relevant variables, from u32 to int. Leave "n" unsigned, for convenience in checking for overflow. And provide a WARN_ON_ONCE() and early return, if overflow occurs. Also, as long as we're tidying up: rename the page array from page, to pages, in order to match the conventions used in most other call sites. Fixes: 20ec628e8007e ("misc: xilinx_sdfec: Add ability to configure LDPC") Cc: Derek Kiernan Cc: Dragan Cvetic Cc: Arnd Bergmann Cc: Greg Kroah-Hartman Cc: Michal Simek Cc: linux-arm-kernel@lists.infradead.org Signed-off-by: John Hubbard Link: https://lore.kernel.org/r/20200527012628.1100649-2-jhubbard@nvidia.com Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin --- drivers/misc/xilinx_sdfec.c | 27 +++++++++++++++++---------- 1 file changed, 17 insertions(+), 10 deletions(-) diff --git a/drivers/misc/xilinx_sdfec.c b/drivers/misc/xilinx_sdfec.c index 48ba7e02bed72..d4c14b617201e 100644 --- a/drivers/misc/xilinx_sdfec.c +++ b/drivers/misc/xilinx_sdfec.c @@ -602,10 +602,10 @@ static int xsdfec_table_write(struct xsdfec_dev *xsdfec, u32 offset, const u32 depth) { u32 reg = 0; - u32 res; - u32 n, i; + int res, i, nr_pages; + u32 n; u32 *addr = NULL; - struct page *page[MAX_NUM_PAGES]; + struct page *pages[MAX_NUM_PAGES]; /* * Writes that go beyond the length of @@ -622,15 +622,22 @@ static int xsdfec_table_write(struct xsdfec_dev *xsdfec, u32 offset, if ((len * XSDFEC_REG_WIDTH_JUMP) % PAGE_SIZE) n += 1; - res = get_user_pages_fast((unsigned long)src_ptr, n, 0, page); - if (res < n) { - for (i = 0; i < res; i++) - put_page(page[i]); + if (WARN_ON_ONCE(n > INT_MAX)) + return -EINVAL; + + nr_pages = n; + + res = get_user_pages_fast((unsigned long)src_ptr, nr_pages, 0, pages); + if (res < nr_pages) { + if (res > 0) { + for (i = 0; i < res; i++) + put_page(pages[i]); + } return -EINVAL; } - for (i = 0; i < n; i++) { - addr = kmap(page[i]); + for (i = 0; i < nr_pages; i++) { + addr = kmap(pages[i]); do { xsdfec_regwrite(xsdfec, base_addr + ((offset + reg) * @@ -639,7 +646,7 @@ static int xsdfec_table_write(struct xsdfec_dev *xsdfec, u32 offset, reg++; } while ((reg < len) && ((reg * XSDFEC_REG_WIDTH_JUMP) % PAGE_SIZE)); - put_page(page[i]); + put_page(pages[i]); } return reg; } -- 2.25.1