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 A38D6C433EF for ; Mon, 6 Dec 2021 21:44:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1351335AbhLFVrv (ORCPT ); Mon, 6 Dec 2021 16:47:51 -0500 Received: from out2.migadu.com ([188.165.223.204]:63841 "EHLO out2.migadu.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1351069AbhLFVru (ORCPT ); Mon, 6 Dec 2021 16:47:50 -0500 X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1638827060; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=CDfDFpOAo922pZ0chQAMNz9tzdyiLXIp8K+CHBQuOYo=; b=gbVFChOrfx9TbOhvcPZkQHwrv+Btc9qpYHzIIr39UxSGbk4K6PLE6TQJhV4xwYqedXDtA1 eteMfFOiRbRw6/xRRY7CVQvzYoJOgTnaN2FZmwfaA1uo8R8M0hgv1WVY+xbvnlc0QnCDgV qxPAc3KLVfumtS7wA8rwFlkCTln8M8o= 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 , Mark Rutland , linux-arm-kernel@lists.infradead.org, Evgenii Stepanov , linux-kernel@vger.kernel.org, Andrey Konovalov Subject: [PATCH v2 05/34] kasan, page_alloc: init memory of skipped pages on free Date: Mon, 6 Dec 2021 22:43:42 +0100 Message-Id: In-Reply-To: References: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Migadu-Flow: FLOW_OUT X-Migadu-Auth-User: linux.dev 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. Reordering kasan_poison_pages() and kernel_init_free_pages() is OK, since kernel_init_free_pages() can handle poisoned memory. Fixes: 7a3b83537188 ("kasan: use separate (un)poison implementation for integrated init") Signed-off-by: Andrey Konovalov --- Changes v1->v2: - Reorder kasan_poison_pages() and free_pages_prepare() in this patch instead of doing it in the previous one. --- mm/page_alloc.c | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-) diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 15f76bc1fa3e..2ada09a58e4b 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -1360,11 +1360,16 @@ 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 (init && !kasan_has_integrated_init()) - kernel_init_free_pages(page, 1 << order); - if (!skip_kasan_poison) + if (!skip_kasan_poison) { kasan_poison_pages(page, order, 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); + /* * arch_free_page() can make the page's contents inaccessible. s390 * does this. So nothing which can access the page's contents should -- 2.25.1