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 1C63BC2D0C8 for ; Fri, 6 Dec 2019 13:54:31 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id D45F224677 for ; Fri, 6 Dec 2019 13:54:30 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org D45F224677 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 41FF86B162D; Fri, 6 Dec 2019 08:54:26 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 3D1EF6B162E; Fri, 6 Dec 2019 08:54:26 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 30E4D6B162F; Fri, 6 Dec 2019 08:54:26 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0005.hostedemail.com [216.40.44.5]) by kanga.kvack.org (Postfix) with ESMTP id 195CF6B162D for ; Fri, 6 Dec 2019 08:54:26 -0500 (EST) Received: from smtpin21.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with SMTP id CF0A38248041 for ; Fri, 6 Dec 2019 13:54:25 +0000 (UTC) X-FDA: 76234861290.21.page17_43bc29f1e0e16 X-HE-Tag: page17_43bc29f1e0e16 X-Filterd-Recvd-Size: 2673 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by imf29.hostedemail.com (Postfix) with ESMTP for ; Fri, 6 Dec 2019 13:54:25 +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 951F3113E; Fri, 6 Dec 2019 05:54:24 -0800 (PST) Received: from e112269-lin.cambridge.arm.com (e112269-lin.cambridge.arm.com [10.1.194.43]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 157723F718; Fri, 6 Dec 2019 05:54:21 -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 v16 14/25] mm: pagewalk: fix termination condition in walk_pte_range() Date: Fri, 6 Dec 2019 13:53:05 +0000 Message-Id: <20191206135316.47703-15-steven.price@arm.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20191206135316.47703-1-steven.price@arm.com> References: <20191206135316.47703-1-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 1b9a3ba24c51..88104ab00a97 100644 --- a/mm/pagewalk.c +++ b/mm/pagewalk.c @@ -18,9 +18,9 @@ static int walk_pte_range(pmd_t *pmd, unsigned long add= r, unsigned long end, 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++; } =20 --=20 2.20.1