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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7B996C433EF for ; Wed, 6 Oct 2021 12:46:46 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 28F1460F59 for ; Wed, 6 Oct 2021 12:46:46 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 28F1460F59 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=kvack.org Received: by kanga.kvack.org (Postfix) id B35C86B006C; Wed, 6 Oct 2021 08:46:45 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id AE57E900002; Wed, 6 Oct 2021 08:46:45 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 9ADBA6B0073; Wed, 6 Oct 2021 08:46:45 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0096.hostedemail.com [216.40.44.96]) by kanga.kvack.org (Postfix) with ESMTP id 899746B006C for ; Wed, 6 Oct 2021 08:46:45 -0400 (EDT) Received: from smtpin35.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with ESMTP id 3BE8E2AEE4 for ; Wed, 6 Oct 2021 12:46:45 +0000 (UTC) X-FDA: 78665986770.35.955B899 Received: from casper.infradead.org (casper.infradead.org [90.155.50.34]) by imf29.hostedemail.com (Postfix) with ESMTP id E0E249013A4F for ; Wed, 6 Oct 2021 12:46:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=Content-Transfer-Encoding:MIME-Version: References:In-Reply-To:Message-Id:Date:Subject:Cc:To:From:Sender:Reply-To: Content-Type:Content-ID:Content-Description; bh=F9+gzjnmeCRoXMNmnYDpwpAyHVo53iZYHJVy+GWxplw=; b=rX49CiluVC1r7n+HoTRSFlD5/+ KZoQGTghfgS5JgEHFeTj+Y4k6Vn9xTNkEdRDkb61fBIPoOhCcY9fjCBQbnKFiJtq7XCDJ0RVblwJG FlNhMo+DHCeL2j6MkwfLXKwFhMrKAvJqhF0PI5ncofDcqI6V+rzwkX8bwQOoNM1bTZ5fuKO08mT6X v+hSfPvhIIJa5nDlFKWUgCMdXteOBj7f161vI47L9u/CjAV6+25SsgaSZgsIfiaofdhRP18Nvd4Eb k7XdUH+0H/x+axJeK1w26tcXMYnFaXPdJ7PPV8EYLZEd0eVgNxb+FxH/v1H4DSzSnstEpfH4eVMS7 BhHriixQ==; Received: from willy by casper.infradead.org with local (Exim 4.94.2 #2 (Red Hat Linux)) id 1mY6Ho-000sat-Lz; Wed, 06 Oct 2021 12:44:58 +0000 From: "Matthew Wilcox (Oracle)" To: Kees Cook Cc: "Matthew Wilcox (Oracle)" , linux-mm@kvack.org, Thomas Gleixner Subject: [PATCH v2 3/3] mm/usercopy: Detect compound page overruns Date: Wed, 6 Oct 2021 13:42:26 +0100 Message-Id: <20211006124226.209484-4-willy@infradead.org> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20211006124226.209484-1-willy@infradead.org> References: <20211006124226.209484-1-willy@infradead.org> MIME-Version: 1.0 X-Rspamd-Queue-Id: E0E249013A4F X-Stat-Signature: jae9pufagjeqpk3w99w8ajjppdatt4ft Authentication-Results: imf29.hostedemail.com; dkim=pass header.d=infradead.org header.s=casper.20170209 header.b=rX49Cilu; spf=none (imf29.hostedemail.com: domain of willy@infradead.org has no SPF policy when checking 90.155.50.34) smtp.mailfrom=willy@infradead.org; dmarc=none X-Rspamd-Server: rspam06 X-HE-Tag: 1633524404-937031 Content-Transfer-Encoding: quoted-printable 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: Move the compound page overrun detection out of CONFIG_HARDENED_USERCOPY_PAGESPAN so it's enabled for more people. Signed-off-by: Matthew Wilcox (Oracle) Acked-by: Kees Cook --- mm/usercopy.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) diff --git a/mm/usercopy.c b/mm/usercopy.c index 63476e1506e0..b825c4344917 100644 --- a/mm/usercopy.c +++ b/mm/usercopy.c @@ -194,11 +194,6 @@ static inline void check_page_span(const void *ptr, = unsigned long n, ((unsigned long)end & (unsigned long)PAGE_MASK))) return; =20 - /* Allow if fully inside the same compound (__GFP_COMP) page. */ - endpage =3D virt_to_head_page(end); - if (likely(endpage =3D=3D page)) - return; - /* * Reject if range is entirely either Reserved (i.e. special or * device memory), or CMA. Otherwise, reject since the object spans @@ -258,6 +253,11 @@ static inline void check_heap_object(const void *ptr= , unsigned long n, if (PageSlab(page)) { /* Check slab allocator for flags and size. */ __check_heap_object(ptr, n, page, to_user); + } else if (PageHead(page)) { + /* A compound allocation */ + unsigned long offset =3D ptr - page_address(page); + if (offset + n > page_size(page)) + usercopy_abort("page alloc", NULL, to_user, offset, n); } else { /* Verify object does not incorrectly span multiple pages. */ check_page_span(ptr, n, page, to_user); --=20 2.32.0