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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7304AC3F6B0 for ; Mon, 8 Aug 2022 01:32:05 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id CFD8A8E0002; Sun, 7 Aug 2022 21:32:04 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id C873E8E0001; Sun, 7 Aug 2022 21:32:04 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id B277D8E0002; Sun, 7 Aug 2022 21:32:04 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0014.hostedemail.com [216.40.44.14]) by kanga.kvack.org (Postfix) with ESMTP id 9DBCA8E0001 for ; Sun, 7 Aug 2022 21:32:04 -0400 (EDT) Received: from smtpin14.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay03.hostedemail.com (Postfix) with ESMTP id 5A2D9A0903 for ; Mon, 8 Aug 2022 01:32:04 +0000 (UTC) X-FDA: 79774699368.14.9568F05 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by imf11.hostedemail.com (Postfix) with ESMTP id D119C4017F for ; Mon, 8 Aug 2022 01:32:03 +0000 (UTC) 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 DFB50B80E05; Mon, 8 Aug 2022 01:32:01 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 82E90C43141; Mon, 8 Aug 2022 01:31:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1659922320; bh=Cy0VXR0/pBUrCrS9LsefsGH8QEVj0tWVRheqGk50Gvw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=RR9VxMZ14ZkgCfB1sghpr8lgUyDR0E7JHBGPa6cVegge8YheLffM0qRI09AK4jUeZ DvFqIq51AhFEyLK8cVoO+6QRzlRP9ciXj4wPPL5LgUZfUvbbBNlb041eGoJTuq0zNB OvUUWXXLg8/WSWvn3X0EQ20LGH5zRXINJ1/io0IoX19Tx2RSee03TMdzPuJc3HPbtz A3VmK2xwoGKNt01fMTTwRhOv9R5EpB8ozfmDHo4XTOH9/XUtZQeJKrJCREC6JzHkXp 5kJE94l23C4LuJ1xA0VD53SkE8ramDeOtffW5FU2Oy6kivYQVRzbE4bGB0wfX+32NB 6g5Sqn/lni8Pw== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Catalin Marinas , Andrey Konovalov , Andrey Ryabinin , Vincenzo Frascino , Will Deacon , Sasha Levin , kasan-dev@googlegroups.com, linux-mm@kvack.org Subject: [PATCH AUTOSEL 5.19 10/58] mm: kasan: Ensure the tags are visible before the tag in page->flags Date: Sun, 7 Aug 2022 21:30:28 -0400 Message-Id: <20220808013118.313965-10-sashal@kernel.org> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20220808013118.313965-1-sashal@kernel.org> References: <20220808013118.313965-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1659922324; a=rsa-sha256; cv=none; b=YQ4Y05DxmGenJMvNdMeTCmEUyh+CWAWbTLCh2OOjxFY0vSjSWsdeF7XqAAhLyMge75wGj0 EDNOI9c/q965epS66paGd9x5UqQY5/4uLe0IknXjKKrOLSFlRhAzMrDLxr8/IuQeD1XOeB wFiI2TxlnxKqqsVu7sU7NUrjdGKKdnM= ARC-Authentication-Results: i=1; imf11.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=RR9VxMZ1; spf=pass (imf11.hostedemail.com: domain of sashal@kernel.org designates 145.40.68.75 as permitted sender) smtp.mailfrom=sashal@kernel.org; dmarc=pass (policy=none) header.from=kernel.org ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1659922324; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=rd8ZKdn/WQ0KEm6ZZRaSem3F0aJ3Qe54rAM+TlPiyeE=; b=VuwC7JVKySmUOgRfrRw3W8VL0ihbp6k459kBGs2NUrIP1W3q0ePpk1iP341HI6MEBU+lHa Lo5oBWmJpqJDXqBHjFg6sQgLHk8W/PeIpHAfN1fxdHSuVnRCzekSp3lqTaYC7D9hZFD7n+ 99pEX9o9ubzyOsS/s1S9Gk6UkgseB1I= X-Rspamd-Queue-Id: D119C4017F X-Rspam-User: X-Rspamd-Server: rspam11 Authentication-Results: imf11.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=RR9VxMZ1; spf=pass (imf11.hostedemail.com: domain of sashal@kernel.org designates 145.40.68.75 as permitted sender) smtp.mailfrom=sashal@kernel.org; dmarc=pass (policy=none) header.from=kernel.org X-Stat-Signature: pypayioi5mbc4e11ci6rtb34as1g8ftx X-HE-Tag: 1659922323-437088 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: From: Catalin Marinas [ Upstream commit ed0a6d1d973e9763989b44913ae1bd2a5d5d5777 ] __kasan_unpoison_pages() colours the memory with a random tag and stores it in page->flags in order to re-create the tagged pointer via page_to_virt() later. When the tag from the page->flags is read, ensure that the in-memory tags are already visible by re-ordering the page_kasan_tag_set() after kasan_unpoison(). The former already has barriers in place through try_cmpxchg(). On the reader side, the order is ensured by the address dependency between page->flags and the memory access. Signed-off-by: Catalin Marinas Reviewed-by: Andrey Konovalov Cc: Andrey Ryabinin Cc: Vincenzo Frascino Reviewed-by: Vincenzo Frascino Link: https://lore.kernel.org/r/20220610152141.2148929-2-catalin.marinas@arm.com Signed-off-by: Will Deacon Signed-off-by: Sasha Levin --- mm/kasan/common.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/mm/kasan/common.c b/mm/kasan/common.c index c40c0e7b3b5f..78be2beb7453 100644 --- a/mm/kasan/common.c +++ b/mm/kasan/common.c @@ -108,9 +108,10 @@ void __kasan_unpoison_pages(struct page *page, unsigned int order, bool init) return; tag = kasan_random_tag(); + kasan_unpoison(set_tag(page_address(page), tag), + PAGE_SIZE << order, init); for (i = 0; i < (1 << order); i++) page_kasan_tag_set(page + i, tag); - kasan_unpoison(page_address(page), PAGE_SIZE << order, init); } void __kasan_poison_pages(struct page *page, unsigned int order, bool init) -- 2.35.1