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=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable 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 6D876C433E0 for ; Mon, 8 Jun 2020 23:17:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 41A6120870 for ; Mon, 8 Jun 2020 23:17:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1591658232; bh=laFJJFYyv4B1e4mrKe19o3ReXIflnahoOiDPh8QGyZk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=YCxc5vvvQS1/hjuT1x9Fa5c4jAOu7mYxXrFwJIHM9TgB+21BxCj3Ke4037XQHleIH 5UWLUsYgRYhzh5RJ1L9XCi5nW2Lq6OpdCeAsPn/IEkx0NdANyNJVQUd8nycGL8YFso WTbPxSMP7om5fsJg60EbaFJsjNfbb7zY2fQK/uWs= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730400AbgFHXRK (ORCPT ); Mon, 8 Jun 2020 19:17:10 -0400 Received: from mail.kernel.org ([198.145.29.99]:34006 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728111AbgFHXN7 (ORCPT ); Mon, 8 Jun 2020 19:13:59 -0400 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id D51D0212CC; Mon, 8 Jun 2020 23:13:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1591658039; bh=laFJJFYyv4B1e4mrKe19o3ReXIflnahoOiDPh8QGyZk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=LGRxUixesW2uS95Uj6emrvxSuwqRLDlkZoqsq5jt8q4Ri68zqkYzc5UaBcm5J0trs ka4/wdOHnhu2NFuPDI1keFJsGh5Rr4OjrJQKznig5vA+fOK4Sa2advOcgNFX9tjbbQ jWpebJk7oMWknOQrOPzbi7xQO+0U/DJjS7gcuDzY= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Al Viro , stable@kernel.org, Thiago Macieira , Sasha Levin , linux-fsdevel@vger.kernel.org Subject: [PATCH AUTOSEL 5.6 089/606] fix multiplication overflow in copy_fdtable() Date: Mon, 8 Jun 2020 19:03:34 -0400 Message-Id: <20200608231211.3363633-89-sashal@kernel.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200608231211.3363633-1-sashal@kernel.org> References: <20200608231211.3363633-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore 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 c8a4e4c86e55..abb8b7081d7a 100644 --- a/fs/file.c +++ b/fs/file.c @@ -70,7 +70,7 @@ 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