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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id A52B2C3F6B0 for ; Thu, 11 Aug 2022 16:21:29 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237735AbiHKQV1 (ORCPT ); Thu, 11 Aug 2022 12:21:27 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58334 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237656AbiHKQUE (ORCPT ); Thu, 11 Aug 2022 12:20:04 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A8C4210FC7; Thu, 11 Aug 2022 09:01:54 -0700 (PDT) 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 5FAA5B82166; Thu, 11 Aug 2022 16:01:53 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 93FDBC433C1; Thu, 11 Aug 2022 16:01:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1660233712; bh=xGPcd112oX8lfCcJLqKqMEUwHG5cYMcLjULpMYNSNpY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=KPt5Wim+Q+7TLhPlqTS8cmg6pRmlSoYEy9k3pgpBj4UWhn9uQwHRusXdZIabWZBTW FV+ll5SRpe/Jmb5vVrkCImAJt2GTI+M3+LziU4ltL8vro4xUyF6X4xUEaoYi1VZqMl jsUiJO2tcJA/iMEfZVtf+lQ1VtU92gFJHzAmi/xOKjil7bJbv9QxKSe7cLnellejBN 9eXzfUxMGrt1esnFxbQ/zppmfG1Jg7425Up5ptwcjcszfCu5gWhDQ5dvFHR61A9wPo 61nI0ZzEeLWtY0eaCHQZPeZd2+uLhCP40GfksiDBwgZokRSlkzBGZIgEafreWEJStv EnreHSOjjak8g== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Al Viro , Jeff Layton , Sasha Levin Subject: [PATCH AUTOSEL 5.15 45/69] iov_iter_get_pages{,_alloc}(): cap the maxsize with MAX_RW_COUNT Date: Thu, 11 Aug 2022 11:55:54 -0400 Message-Id: <20220811155632.1536867-45-sashal@kernel.org> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20220811155632.1536867-1-sashal@kernel.org> References: <20220811155632.1536867-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Al Viro [ Upstream commit 7392ed1734c319150b5ddec3f192a6405728e8d0 ] All callers can and should handle iov_iter_get_pages() returning fewer pages than requested. All in-kernel ones do. And it makes the arithmetical overflow analysis much simpler... Reviewed-by: Jeff Layton Signed-off-by: Al Viro Signed-off-by: Sasha Levin --- lib/iov_iter.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/lib/iov_iter.c b/lib/iov_iter.c index 6cf2d66fb839..ce24835abe55 100644 --- a/lib/iov_iter.c +++ b/lib/iov_iter.c @@ -1522,6 +1522,8 @@ ssize_t iov_iter_get_pages(struct iov_iter *i, maxsize = i->count; if (!maxsize) return 0; + if (maxsize > MAX_RW_COUNT) + maxsize = MAX_RW_COUNT; if (likely(iter_is_iovec(i))) { unsigned int gup_flags = 0; @@ -1642,6 +1644,8 @@ ssize_t iov_iter_get_pages_alloc(struct iov_iter *i, maxsize = i->count; if (!maxsize) return 0; + if (maxsize > MAX_RW_COUNT) + maxsize = MAX_RW_COUNT; if (likely(iter_is_iovec(i))) { unsigned int gup_flags = 0; -- 2.35.1