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 4D912C25B0F for ; Thu, 11 Aug 2022 15:41:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235928AbiHKPln (ORCPT ); Thu, 11 Aug 2022 11:41:43 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41128 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236074AbiHKPk0 (ORCPT ); Thu, 11 Aug 2022 11:40:26 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9F5EC74CFD; Thu, 11 Aug 2022 08:36:07 -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 dfw.source.kernel.org (Postfix) with ESMTPS id 0874F6164A; Thu, 11 Aug 2022 15:36:07 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id C5F6EC433C1; Thu, 11 Aug 2022 15:36:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1660232166; bh=2Qn+Sx9L2R/gcJM5MIhzFEiaDv+YJaCyn/9dOfkcXT4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=QzwbMGRn0xW0g2ErZnpa4WFLcIjNykpm4/AInvqV7QJeqY2ytzhdcqB9qhT+bek8w S/gqmHpzHrLuUXkdnwe5lqzEGFGt+qr9teCO+ShljwgloCnJXV5pMSy0EmtN7mglld khkQGzt0IbAQjUpfDW10L40lafgGwGbfULrfLSOg/38FVwluMsimo4z92xim/x5R0+ D/r0l1r9FP0PTI9BCW06mGDldLz8jSpV7uNgV1ShO68Gey1aGqwDYtDL198m66rK22 ahpvRsCJrMQQz91gwSwtr706vn0GZQAu7UFyt9YHh2xO9/6O75TCluhDPycWa3gaZQ 4JhgZkF2oKd4Q== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Al Viro , Jeff Layton , Sasha Levin Subject: [PATCH AUTOSEL 5.19 061/105] iov_iter_get_pages{,_alloc}(): cap the maxsize with MAX_RW_COUNT Date: Thu, 11 Aug 2022 11:27:45 -0400 Message-Id: <20220811152851.1520029-61-sashal@kernel.org> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20220811152851.1520029-1-sashal@kernel.org> References: <20220811152851.1520029-1-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 0b64695ab632..ea588628828b 100644 --- a/lib/iov_iter.c +++ b/lib/iov_iter.c @@ -1520,6 +1520,8 @@ 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; @@ -1640,6 +1642,8 @@ 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