From patchwork Mon Aug 7 12:18:47 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Peter Zijlstra X-Patchwork-Id: 132049 Return-Path: Delivered-To: ouuuleilei@gmail.com Received: by 2002:a59:c44e:0:b0:3f2:4152:657d with SMTP id w14csp1478897vqr; Mon, 7 Aug 2023 07:11:31 -0700 (PDT) X-Google-Smtp-Source: AGHT+IHlGwjLw42a8/6R/dCSBMCDm/weSCABJe8X4wjtYKd4B8fd/ATt+HB7P11mYNRMzofmGFCC X-Received: by 2002:a05:6a00:cc6:b0:67a:8fc7:1b61 with SMTP id b6-20020a056a000cc600b0067a8fc71b61mr11926616pfv.11.1691417490923; Mon, 07 Aug 2023 07:11:30 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1691417490; cv=none; d=google.com; s=arc-20160816; b=QhW0DTYZyhEBmmt32y/mPE0+77BUibJ15Z3KRy0zJzrfJU+eZcbuD1lZcVFP00ZbDe crSK/v+6TA9qLiKkNZSqz7hnqRpu//cwgkCvNbQXHXP/atxYEC+8Nqcuehvn2cSbEI2t vPeoVYm60MPmIrusHIP7I3N2/dhsMXdhPm2ZAH97zJbaMW7VWVworhYr5MGPTOmn7wvg esHZpcGf1rzcUAH4OO8dLGauJTJFiDmdNLbcuG97dZ30UHUxc9Z3VDSHUco1dvHYkPbF VFF6DqRFOWXK2Sq3c1RNJt4eLwPR0xnfVa7uYP2Yy/jmIFg2kDYjZwnupLri5s7t08vJ g6Kg== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:mime-version:references:subject:cc:to:from:date :user-agent:message-id:dkim-signature; bh=1Epi3uPitQ1on7D3YBD3uiLy0TLxJfWf5bL2Vyq95Dw=; fh=EjmxZ37PYlcfWlhzAqi5wmPe8R8k7/dCt/LKb5qak3s=; b=f54X8PJX5Yb3VMygepTL6BHCeb0N8XXKuIczftZwTCqzdg2+YSjJWWje3w1HTbgV/n wbTdZjW3j2Yk4mF8vX7jU4sc9ity7AqLGs/aXsVNBehfNFQusJdXPbSZ2bEO3CLbhmxl 8Eu99iwQ1CetaV/77dNGHv7xxOa6PwEw5XvcJu5d8DJJ4yfsMgM+pK3vLUpOyzHm2sAg LKpU+n97G06zE/Ss+WwNUe4diahZWKbV2Oxo0KZuMjC7+CGoxAGkFPX6RQQz9juWJTlA ZbzL21bWa8hpMIYRx+FBxm90YI8IpJEaT9lisBxaK0V08NW04xTQw3A5nULXvQecWPvq BX8A== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@infradead.org header.s=desiato.20200630 header.b=Co5btgZE; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: from out1.vger.email (out1.vger.email. [2620:137:e000::1:20]) by mx.google.com with ESMTP id f12-20020a056a001acc00b00686da99493bsi5847930pfv.221.2023.08.07.07.11.18; Mon, 07 Aug 2023 07:11:30 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20; Authentication-Results: mx.google.com; dkim=pass header.i=@infradead.org header.s=desiato.20200630 header.b=Co5btgZE; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233671AbjHGMhl (ORCPT + 99 others); Mon, 7 Aug 2023 08:37:41 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36538 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233603AbjHGMhT (ORCPT ); Mon, 7 Aug 2023 08:37:19 -0400 Received: from desiato.infradead.org (desiato.infradead.org [IPv6:2001:8b0:10b:1:d65d:64ff:fe57:4e05]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0BA4C10FE; Mon, 7 Aug 2023 05:37:17 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=desiato.20200630; h=Content-Type:MIME-Version:References: Subject:Cc:To:From:Date:Message-ID:Sender:Reply-To:Content-Transfer-Encoding: Content-ID:Content-Description:In-Reply-To; bh=1Epi3uPitQ1on7D3YBD3uiLy0TLxJfWf5bL2Vyq95Dw=; b=Co5btgZE3bcLd6z8lfAD2yNF2L ng1KYKs/j+LRyQXyEVivIfQ47vWvqix6Wv8uRYB11Zf6YAPWQ2Kzx6ArCzkOTTWGT+8XCPQ7uXuEW vDAkp51vggTuX10agZQ0yg3W576dARN+M8hwxlyoPwRGjE1XOB0MhUIjhFWN9aJ7vL1eea62cfgP6 NvnVZop5Z9+vAD7rvcXJhH1RecuHIqRh/u8NJKUmTnog33pDpfH/OHUZ4xTe7JYu2pvydxZvXodvi 2IHrCULJhmfjc6eogA90H7UhlDF3UynqeHLBuojaS/A/nCPh7Z4kvOMBaOLWLDVm17tOL1bQyvxXM L0ZUXWwQ==; Received: from j130084.upc-j.chello.nl ([24.132.130.84] helo=noisy.programming.kicks-ass.net) by desiato.infradead.org with esmtpsa (Exim 4.96 #2 (Red Hat Linux)) id 1qSzTk-003oSd-1J; Mon, 07 Aug 2023 12:36:56 +0000 Received: from hirez.programming.kicks-ass.net (hirez.programming.kicks-ass.net [192.168.1.225]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits)) (Client did not present a certificate) by noisy.programming.kicks-ass.net (Postfix) with ESMTPS id D1BF4300473; Mon, 7 Aug 2023 14:36:54 +0200 (CEST) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 0) id 986A62021C3D7; Mon, 7 Aug 2023 14:36:54 +0200 (CEST) Message-ID: <20230807123323.020870574@infradead.org> User-Agent: quilt/0.66 Date: Mon, 07 Aug 2023 14:18:47 +0200 From: Peter Zijlstra To: tglx@linutronix.de, axboe@kernel.dk Cc: linux-kernel@vger.kernel.org, peterz@infradead.org, mingo@redhat.com, dvhart@infradead.org, dave@stgolabs.net, andrealmeid@igalia.com, Andrew Morton , urezki@gmail.com, hch@infradead.org, lstoakes@gmail.com, Arnd Bergmann , linux-api@vger.kernel.org, linux-mm@kvack.org, linux-arch@vger.kernel.org, malteskarupke@web.de Subject: [PATCH v2 04/14] futex: Validate futex value against futex size References: <20230807121843.710612856@infradead.org> MIME-Version: 1.0 X-Spam-Status: No, score=-2.1 required=5.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,RCVD_IN_DNSWL_BLOCKED, SPF_HELO_NONE,SPF_NONE autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org X-getmail-retrieved-from-mailbox: INBOX X-GMAIL-THRID: 1773579786853184155 X-GMAIL-MSGID: 1773579786853184155 Ensure the futex value fits in the given futex size. Since this adds a constraint to an existing syscall, it might possibly change behaviour. Currently the value would be truncated to a u32 and any high bits would get silently lost. Signed-off-by: Peter Zijlstra (Intel) Reviewed-by: Thomas Gleixner --- kernel/futex/futex.h | 10 ++++++++++ kernel/futex/syscalls.c | 3 +++ 2 files changed, 13 insertions(+) --- a/kernel/futex/futex.h +++ b/kernel/futex/futex.h @@ -85,6 +85,16 @@ static inline unsigned int futex_size(un return 1 << (flags & FLAGS_SIZE_MASK); } +static inline bool futex_validate_input(unsigned int flags, u64 val) +{ + int bits = 8 * futex_size(flags); + + if (bits < 64 && (val >> bits)) + return false; + + return true; +} + #ifdef CONFIG_FAIL_FUTEX extern bool should_fail_futex(bool fshared); #else --- a/kernel/futex/syscalls.c +++ b/kernel/futex/syscalls.c @@ -209,6 +209,9 @@ static int futex_parse_waitv(struct fute if (!futex_flags_valid(flags)) return -EINVAL; + if (!futex_validate_input(flags, aux.val)) + return -EINVAL; + futexv[i].w.flags = flags; futexv[i].w.val = aux.val; futexv[i].w.uaddr = aux.uaddr;