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=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,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 06FCFC433E1 for ; Tue, 26 May 2020 19:33:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id CA43B20776 for ; Tue, 26 May 2020 19:33:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1590521587; bh=NeOqInKTzxN7ojom7Vp7pT2oQY1bMAcK0kOuJJCDwnE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=gFqDzGSjfsDOlWdBa/kd2UjrbM9btimRr6e2t5JIOI15FwKfdaQkq/r1yWsy3Tmpq gadzyJ7EvV1cTZ1SrQki6BjfgNQGTx2jdmUbZay5dAckMVgnxVsIlZRHt1TQVd5flv hN/Gseb5OV25Cm4Y7Efvz54Ihmv+kf97TSUcJRx8= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389853AbgEZS4a (ORCPT ); Tue, 26 May 2020 14:56:30 -0400 Received: from mail.kernel.org ([198.145.29.99]:49220 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2389823AbgEZS4Z (ORCPT ); Tue, 26 May 2020 14:56:25 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 17D5920870; Tue, 26 May 2020 18:56:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1590519385; bh=NeOqInKTzxN7ojom7Vp7pT2oQY1bMAcK0kOuJJCDwnE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=uPIMLpUa4c3atZsLKb0SDf9VEHxhm9G64Zg/JA1k61/lwYLBjKpgwlBgN9EaMNVWS 2zNwBiP2TJ0NQOhcTJ/iZ/gFElXA6PT54uKHn8Er48wrxX8Rojd/uw31+fsGclNHya M26ksDFtvVfeyFvSKRadTLryBGIg9T0tcwaPnJ6c= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Thiago Macieira , Al Viro , Sasha Levin , stable@kernel.org Subject: [PATCH 4.4 07/65] fix multiplication overflow in copy_fdtable() Date: Tue, 26 May 2020 20:52:26 +0200 Message-Id: <20200526183908.706497453@linuxfoundation.org> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20200526183905.988782958@linuxfoundation.org> References: <20200526183905.988782958@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Al Viro [ Upstream commit 4e89b7210403fa4a8acafe7c602b6212b7af6c3b ] cpy and set really should be size_t; we won't get an overflow on that, since sysctl_nr_open can't be set above ~(size_t)0 / sizeof(void *), so nr that would've managed to overflow size_t on that multiplication won't get anywhere near copy_fdtable() - we'll fail with EMFILE before that. Cc: stable@kernel.org # v2.6.25+ Fixes: 9cfe015aa424 (get rid of NR_OPEN and introduce a sysctl_nr_open) Reported-by: Thiago Macieira Signed-off-by: Al Viro Signed-off-by: Sasha Levin --- fs/file.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/file.c b/fs/file.c index 7e9eb65a2912..090015401c55 100644 --- a/fs/file.c +++ b/fs/file.c @@ -88,7 +88,7 @@ static void copy_fd_bitmaps(struct fdtable *nfdt, struct fdtable *ofdt, */ static void copy_fdtable(struct fdtable *nfdt, struct fdtable *ofdt) { - unsigned int cpy, set; + size_t cpy, set; BUG_ON(nfdt->max_fds < ofdt->max_fds); -- 2.25.1