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 X-Spam-Level: X-Spam-Status: No, score=-9.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id DD424C43603 for ; Wed, 18 Dec 2019 16:25:10 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id A4E31227BF for ; Wed, 18 Dec 2019 16:25:10 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org A4E31227BF Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id B0E968E012A; Wed, 18 Dec 2019 11:25:07 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id A49D58E00F5; Wed, 18 Dec 2019 11:25:07 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 8E7908E012A; Wed, 18 Dec 2019 11:25:07 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0080.hostedemail.com [216.40.44.80]) by kanga.kvack.org (Postfix) with ESMTP id 749908E00F5 for ; Wed, 18 Dec 2019 11:25:07 -0500 (EST) Received: from smtpin13.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay01.hostedemail.com (Postfix) with SMTP id 3633F180AD807 for ; Wed, 18 Dec 2019 16:25:07 +0000 (UTC) X-FDA: 76278786654.13.bomb66_2ca81eb4a6f30 X-HE-Tag: bomb66_2ca81eb4a6f30 X-Filterd-Recvd-Size: 2662 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by imf32.hostedemail.com (Postfix) with ESMTP for ; Wed, 18 Dec 2019 16:25:06 +0000 (UTC) Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 9480111B3; Wed, 18 Dec 2019 08:25:05 -0800 (PST) Received: from e112269-lin.arm.com (e112269-lin.cambridge.arm.com [10.1.196.56]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 0ED3D3F719; Wed, 18 Dec 2019 08:25:02 -0800 (PST) From: Steven Price To: Andrew Morton , linux-mm@kvack.org Cc: Steven Price , Andy Lutomirski , Ard Biesheuvel , Arnd Bergmann , Borislav Petkov , Catalin Marinas , Dave Hansen , Ingo Molnar , James Morse , =?UTF-8?q?J=C3=A9r=C3=B4me=20Glisse?= , Peter Zijlstra , Thomas Gleixner , Will Deacon , x86@kernel.org, "H. Peter Anvin" , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, Mark Rutland , "Liang, Kan" Subject: [PATCH v17 14/23] mm: pagewalk: fix termination condition in walk_pte_range() Date: Wed, 18 Dec 2019 16:23:53 +0000 Message-Id: <20191218162402.45610-15-steven.price@arm.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20191218162402.45610-1-steven.price@arm.com> References: <20191218162402.45610-1-steven.price@arm.com> MIME-Version: 1.0 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: If walk_pte_range() is called with a 'end' argument that is beyond the last page of memory (e.g. ~0UL) then the comparison between 'addr' and 'end' will always fail and the loop will be infinite. Instead change the comparison to >=3D while accounting for overflow. Signed-off-by: Steven Price --- mm/pagewalk.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/mm/pagewalk.c b/mm/pagewalk.c index 4b5ee92ba079..6732fc7ac4c8 100644 --- a/mm/pagewalk.c +++ b/mm/pagewalk.c @@ -14,9 +14,9 @@ static int walk_pte_range_inner(pte_t *pte, unsigned lo= ng addr, err =3D ops->pte_entry(pte, addr, addr + PAGE_SIZE, walk); if (err) break; - addr +=3D PAGE_SIZE; - if (addr =3D=3D end) + if (addr >=3D end - PAGE_SIZE) break; + addr +=3D PAGE_SIZE; pte++; } return err; --=20 2.20.1