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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 3F0ECC636D3 for ; Fri, 10 Feb 2023 00:52:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229985AbjBJAwY (ORCPT ); Thu, 9 Feb 2023 19:52:24 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43042 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230207AbjBJAwX (ORCPT ); Thu, 9 Feb 2023 19:52:23 -0500 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A559C6A73E for ; Thu, 9 Feb 2023 16:52:22 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 5C781B82272 for ; Fri, 10 Feb 2023 00:52:21 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id F37E6C4339C; Fri, 10 Feb 2023 00:52:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1675990340; bh=IldnxbjrjGLA96+mnpEOsoJlJKHf0JDp69sNZHD8bOM=; h=Date:To:From:Subject:From; b=jzrXIIWgbzTl2PBWk5HX2+MX7pj46EOnSsfW0Go3862e0F9piEK2VDkPJY4k2KlgE PwypCYZFdDb9gum3G5gp1S7jOF81J4qtUUF2WjhjbbmasBG6D/88GMaOQnWdIDsWo6 tNAuzyDxmP1Mcqc/gYSVmvSMR8LsFy7/xAU5rQc4= Date: Thu, 09 Feb 2023 16:52:19 -0800 To: mm-commits@vger.kernel.org, ira.weiny@intel.com, fmdefrancesco@gmail.com, willy@infradead.org, akpm@linux-foundation.org From: Andrew Morton Subject: [merged mm-stable] mm-add-memcpy_from_file_folio.patch removed from -mm tree Message-Id: <20230210005219.F37E6C4339C@smtp.kernel.org> Precedence: bulk Reply-To: linux-kernel@vger.kernel.org List-ID: X-Mailing-List: mm-commits@vger.kernel.org The quilt patch titled Subject: mm: fix memcpy_from_file_folio() integer underflow has been removed from the -mm tree. Its filename was mm-add-memcpy_from_file_folio.patch This patch was dropped because it was merged into the mm-stable branch of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm ------------------------------------------------------ From: "Matthew Wilcox (Oracle)" Subject: mm: fix memcpy_from_file_folio() integer underflow Date: Fri, 3 Feb 2023 16:28:40 -0500 If we have a HIGHMEM system with a large folio, 'offset' may be larger than PAGE_SIZE, and so min_t will cap at 'len' instead of the intended end-of-page. That can overflow into the next page which is likely to be unmapped and fault, but could theoretically copy the wrong data. Link: https://lkml.kernel.org/r/Y919vmSrtAgsf6K3@casper.infradead.org Fixes: 00cdf76012ab ("mm: add memcpy_from_file_folio()") Signed-off-by: Matthew Wilcox (Oracle) Cc: "Fabio M. De Francesco" Cc: Ira Weiny Signed-off-by: Andrew Morton --- include/linux/highmem.h | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) --- a/include/linux/highmem.h~mm-add-memcpy_from_file_folio +++ a/include/linux/highmem.h @@ -431,9 +431,10 @@ static inline size_t memcpy_from_file_fo size_t offset = offset_in_folio(folio, pos); char *from = kmap_local_folio(folio, offset); - if (folio_test_highmem(folio)) + if (folio_test_highmem(folio)) { + offset = offset_in_page(offset); len = min_t(size_t, len, PAGE_SIZE - offset); - else + } else len = min(len, folio_size(folio) - offset); memcpy(to, from, len); _ Patches currently in -mm which might be from willy@infradead.org are