From patchwork Mon Dec 6 21:43:45 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: andrey.konovalov@linux.dev X-Patchwork-Id: 12659743 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 E9FF1C433F5 for ; Mon, 6 Dec 2021 21:46:34 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 30E006B0089; Mon, 6 Dec 2021 16:44:50 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 2BDC36B008A; Mon, 6 Dec 2021 16:44:50 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 15F186B008C; Mon, 6 Dec 2021 16:44:50 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0233.hostedemail.com [216.40.44.233]) by kanga.kvack.org (Postfix) with ESMTP id 08EAA6B0089 for ; Mon, 6 Dec 2021 16:44:50 -0500 (EST) Received: from smtpin03.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay04.hostedemail.com (Postfix) with ESMTP id CC37888CFB for ; Mon, 6 Dec 2021 21:44:39 +0000 (UTC) X-FDA: 78888699078.03.22B7D13 Received: from out2.migadu.com (out2.migadu.com [188.165.223.204]) by imf24.hostedemail.com (Postfix) with ESMTP id 4EEC8B00009D for ; Mon, 6 Dec 2021 21:44:39 +0000 (UTC) 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=1638827078; 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=TniNgsonCV7N4x8CfBP962yTwJ3ZQbzv223ievd0EoQ=; b=qXzJ+ayG5mWJ+4fHBRfgQ7rHV1m43f11tVvZTtueBObKZIqO936tA6hNbt2mtDAPM+wGfR j41BvO29uhf5X8RLEXtUoa8WtCjvOUbq96/E2or9Xa/6m1wNQ27y1bYuYdYr2LbQ5UqiiA M26Ur3GKXcnb6+j9Dajdhp6czI+tZnI= 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 08/34] kasan: only apply __GFP_ZEROTAGS when memory is zeroed Date: Mon, 6 Dec 2021 22:43:45 +0100 Message-Id: In-Reply-To: References: MIME-Version: 1.0 X-Migadu-Flow: FLOW_OUT X-Migadu-Auth-User: linux.dev X-Rspamd-Server: rspam09 X-Rspamd-Queue-Id: 4EEC8B00009D X-Stat-Signature: 3mg1pbmip19otw7ehtjgxmnfq5cufrzx Authentication-Results: imf24.hostedemail.com; dkim=pass header.d=linux.dev header.s=key1 header.b=qXzJ+ayG; dmarc=pass (policy=none) header.from=linux.dev; spf=pass (imf24.hostedemail.com: domain of andrey.konovalov@linux.dev designates 188.165.223.204 as permitted sender) smtp.mailfrom=andrey.konovalov@linux.dev X-HE-Tag: 1638827079-380335 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: Andrey Konovalov __GFP_ZEROTAGS should only be effective if memory is being zeroed. Currently, hardware tag-based KASAN violates this requirement. Fix by including an initialization check along with checking for __GFP_ZEROTAGS. Signed-off-by: Andrey Konovalov Reviewed-by: Alexander Potapenko --- mm/kasan/hw_tags.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/mm/kasan/hw_tags.c b/mm/kasan/hw_tags.c index 0b8225add2e4..c643740b8599 100644 --- a/mm/kasan/hw_tags.c +++ b/mm/kasan/hw_tags.c @@ -199,11 +199,12 @@ void kasan_alloc_pages(struct page *page, unsigned int order, gfp_t flags) * page_alloc.c. */ bool init = !want_init_on_free() && want_init_on_alloc(flags); + bool init_tags = init && (flags & __GFP_ZEROTAGS); if (flags & __GFP_SKIP_KASAN_POISON) SetPageSkipKASanPoison(page); - if (flags & __GFP_ZEROTAGS) { + if (init_tags) { int i; for (i = 0; i != 1 << order; ++i)