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 0E082C19F2A for ; Thu, 11 Aug 2022 16:02:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237292AbiHKQC4 (ORCPT ); Thu, 11 Aug 2022 12:02:56 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58168 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237206AbiHKQCf (ORCPT ); Thu, 11 Aug 2022 12:02:35 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1EDA1B2DBF; Thu, 11 Aug 2022 08:49:58 -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 6976160A09; Thu, 11 Aug 2022 15:49:38 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 2D6CCC433C1; Thu, 11 Aug 2022 15:49:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1660232977; bh=2Qn+Sx9L2R/gcJM5MIhzFEiaDv+YJaCyn/9dOfkcXT4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=g4Q8V0zyp+gr6HUFeDAe6YifApLoDK8UBfzSnCtQZ2nl2v4G7XLuG2MHJul2kvzJb HWi6C6lsL7WGjdkwp7nP1x4Q6vLKrViqd5voTkzwL+2aKSqG7bvu1NhthWhh9Ictys D3bi1Dr3OM6QGDDinWoGq32I7bKhEJcRlkQqkH7LhveyLUDIWLPjbHtlY2h6Se1AI4 B36+aPOXVDM87hRPvpAURkqAkCkbGrNmZIr73InXnU29Hr47dKZIujqXNkK5fFNvqZ OZAFjAoOa8wHcosmKGqq4TkVgsEt5Kk+s9Y5LJHGAxC1yj7iTE5xvA269l3vY7w9lh eXe8BB80GATHQ== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Al Viro , Jeff Layton , Sasha Levin Subject: [PATCH AUTOSEL 5.18 55/93] iov_iter_get_pages{,_alloc}(): cap the maxsize with MAX_RW_COUNT Date: Thu, 11 Aug 2022 11:41:49 -0400 Message-Id: <20220811154237.1531313-55-sashal@kernel.org> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20220811154237.1531313-1-sashal@kernel.org> References: <20220811154237.1531313-1-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: stable@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