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 07D39C433FE for ; Tue, 30 Nov 2021 21:41:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1344321AbhK3Vo1 (ORCPT ); Tue, 30 Nov 2021 16:44:27 -0500 Received: from out0.migadu.com ([94.23.1.103]:57240 "EHLO out0.migadu.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S240698AbhK3VoE (ORCPT ); Tue, 30 Nov 2021 16:44:04 -0500 X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. From: andrey.konovalov@linux.dev To: Marco Elver , Alexander Potapenko , Vincenzo Frascino , Catalin Marinas , Peter Collingbourne Cc: Andrey Konovalov , Dmitry Vyukov , Andrey Ryabinin , kasan-dev@googlegroups.com, Andrew Morton , linux-mm@kvack.org, Will Deacon , linux-arm-kernel@lists.infradead.org, Evgenii Stepanov , linux-kernel@vger.kernel.org, Andrey Konovalov Subject: [PATCH 05/31] kasan, page_alloc: init memory of skipped pages on free Date: Tue, 30 Nov 2021 22:39:11 +0100 Message-Id: <62e844bae175b9f354cda6f72ba140438e83791a.1638308023.git.andreyknvl@google.com> In-Reply-To: References: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Andrey Konovalov Since commit 7a3b83537188 ("kasan: use separate (un)poison implementation for integrated init"), when all init, kasan_has_integrated_init(), and skip_kasan_poison are true, free_pages_prepare() doesn't initialize the page. This is wrong. Fix it by remembering whether kasan_poison_pages() performed initialization, and call kernel_init_free_pages() if it didn't. Fixes: 7a3b83537188 ("kasan: use separate (un)poison implementation for integrated init") Signed-off-by: Andrey Konovalov --- mm/page_alloc.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 0673db27dd12..2ada09a58e4b 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -1360,9 +1360,14 @@ static __always_inline bool free_pages_prepare(struct page *page, * With hardware tag-based KASAN, memory tags must be set before the * page becomes unavailable via debug_pagealloc or arch_free_page. */ - if (!skip_kasan_poison) + if (!skip_kasan_poison) { kasan_poison_pages(page, order, init); - if (init && !kasan_has_integrated_init()) + + /* Memory is already initialized if KASAN did it internally. */ + if (kasan_has_integrated_init()) + init = false; + } + if (init) kernel_init_free_pages(page, 1 << order); /* -- 2.25.1