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 DAAE7C636CC for ; Mon, 13 Feb 2023 21:49:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230164AbjBMVtE (ORCPT ); Mon, 13 Feb 2023 16:49:04 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40524 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231217AbjBMVtC (ORCPT ); Mon, 13 Feb 2023 16:49:02 -0500 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 06AAF17CDA for ; Mon, 13 Feb 2023 13:49:00 -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 dfw.source.kernel.org (Postfix) with ESMTPS id 9473B6130B for ; Mon, 13 Feb 2023 21:48:59 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id EAD2CC433D2; Mon, 13 Feb 2023 21:48:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1676324939; bh=Bq3ReEgFDKhYLKbmN+bSmMNH6CCANbK/6ASEjeviofw=; h=Date:To:From:Subject:From; b=HR7qulixhU9CFfs65XNxUZmKky1Tj4aK+uK/slBEdq2UAWTrN7F2KY54NySNJs9ji mEp17wYafYKy5l+OlY2CMWI5Bavjr+pEEdbzxiV/jwgx7SigpKPawqdYpO/QnulC7s 6eu5+E/gC34NYX50T1a+lLCrvGkJrLsZegfmtk1U= Date: Mon, 13 Feb 2023 13:48:58 -0800 To: mm-commits@vger.kernel.org, willy@infradead.org, m.szyprowski@samsung.com, alex@ghiti.fr, vishal.moola@gmail.com, akpm@linux-foundation.org From: Andrew Morton Subject: + mm-khugepaged-fix-invalid-page-access-in-release_pte_pages.patch added to mm-unstable branch Message-Id: <20230213214858.EAD2CC433D2@smtp.kernel.org> Precedence: bulk Reply-To: linux-kernel@vger.kernel.org List-ID: X-Mailing-List: mm-commits@vger.kernel.org The patch titled Subject: mm/khugepaged: fix invalid page access in release_pte_pages() has been added to the -mm mm-unstable branch. Its filename is mm-khugepaged-fix-invalid-page-access-in-release_pte_pages.patch This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-khugepaged-fix-invalid-page-access-in-release_pte_pages.patch This patch will later appear in the mm-unstable branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next via the mm-everything branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm and is updated there every 2-3 working days ------------------------------------------------------ From: "Vishal Moola (Oracle)" Subject: mm/khugepaged: fix invalid page access in release_pte_pages() Date: Mon, 13 Feb 2023 13:43:24 -0800 release_pte_pages() converts from a pfn to a folio by using pfn_folio(). If the pte is not mapped, pfn_folio() will result in undefined behavior which ends up causing a kernel panic[1]. Only call pfn_folio() once we have validated that the pte is both valid and mapped to fix the issue. [1] https://lore.kernel.org/linux-mm/ff300770-afe9-908d-23ed-d23e0796e899@samsung.com/ Link: https://lkml.kernel.org/r/20230213214324.34215-1-vishal.moola@gmail.com Signed-off-by: Vishal Moola (Oracle) Fixes: 9bdfeea46f49 ("mm/khugepaged: convert release_pte_pages() to use folios") Reported-by: Marek Szyprowski Debugged-by: Alexandre Ghiti Cc: Matthew Wilcox Signed-off-by: Andrew Morton --- --- a/mm/khugepaged.c~mm-khugepaged-fix-invalid-page-access-in-release_pte_pages +++ a/mm/khugepaged.c @@ -511,11 +511,17 @@ static void release_pte_pages(pte_t *pte while (--_pte >= pte) { pte_t pteval = *_pte; + unsigned long pfn; - folio = pfn_folio(pte_pfn(pteval)); - if (!pte_none(pteval) && !is_zero_pfn(pte_pfn(pteval)) && - !folio_test_large(folio)) - release_pte_folio(folio); + if (pte_none(pteval)) + continue; + pfn = pte_pfn(pteval); + if (is_zero_pfn(pfn)) + continue; + folio = pfn_folio(pfn); + if (folio_test_large(folio)) + continue; + release_pte_folio(folio); } list_for_each_entry_safe(folio, tmp, compound_pagelist, lru) { _ Patches currently in -mm which might be from vishal.moola@gmail.com are mm-khugepaged-fix-invalid-page-access-in-release_pte_pages.patch mm-add-folio_estimated_sharers.patch mm-mempolicy-convert-queue_pages_pmd-to-queue_folios_pmd.patch mm-mempolicy-convert-queue_pages_pte_range-to-queue_folios_pte_range.patch mm-mempolicy-convert-queue_pages_hugetlb-to-queue_folios_hugetlb.patch mm-mempolicy-convert-queue_pages_required-to-queue_folio_required.patch mm-mempolicy-convert-migrate_page_add-to-migrate_folio_add.patch mm-add-folio_get_nontail_page.patch mm-migrate-add-folio_movable_ops.patch mm-migrate-convert-isolate_movable_page-to-use-folios.patch mm-migrate-convert-putback_movable_pages-to-use-folios.patch