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=-6.0 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, 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 A83DFC4360F for ; Mon, 1 Apr 2019 17:37:07 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 770F120880 for ; Mon, 1 Apr 2019 17:37:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1554140227; bh=54NHRBTHi2mywtT3rC7+tDwXZiWp/CR5dG/JQf7aVHk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=1yckxQXwoeZMhCCI2rD252HcvVaOSFnnFPLyyjBzf2peR01zBWYtM8MBr52GErirN 0naB4Nn1X01pW4r6kO7TX2ge8xGHRsPHVuX2etlwNgtR4z64OK4yoFDS1LXUR6Dv8b nAx+yebnWXLXcG4qdmWZIZPFwGrdVZ3OWhNoMNzw= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388127AbfDARhG (ORCPT ); Mon, 1 Apr 2019 13:37:06 -0400 Received: from mail.kernel.org ([198.145.29.99]:49198 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2388118AbfDARhC (ORCPT ); Mon, 1 Apr 2019 13:37:02 -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 0931620830; Mon, 1 Apr 2019 17:37:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1554140221; bh=54NHRBTHi2mywtT3rC7+tDwXZiWp/CR5dG/JQf7aVHk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Oxzjw62xThY2xEP2TMvy/7yh1un95F35lhuxmXqo0O1Oo5uemhtSiX7lv+faF/mjM dIUEYJHiSDO0HtMX0tIL3ngFM0znXpJWcpdB5S0+pFIQRsKXAViMp9MkEHFxGALAGi o71UQyuAvaAuKEv6PP32+9CaFOIMkYaVvQQjm87I= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Chen Jie , Thomas Gleixner , dvhart@infradead.org, peterz@infradead.org, zengweilin@huawei.com Subject: [PATCH 3.18 02/50] futex: Ensure that futex address is aligned in handle_futex_death() Date: Mon, 1 Apr 2019 19:02:45 +0200 Message-Id: <20190401170041.474419222@linuxfoundation.org> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20190401170041.257273804@linuxfoundation.org> References: <20190401170041.257273804@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review X-Patchwork-Hint: ignore 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 3.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Chen Jie commit 5a07168d8d89b00fe1760120714378175b3ef992 upstream. The futex code requires that the user space addresses of futexes are 32bit aligned. sys_futex() checks this in futex_get_keys() but the robust list code has no alignment check in place. As a consequence the kernel crashes on architectures with strict alignment requirements in handle_futex_death() when trying to cmpxchg() on an unaligned futex address which was retrieved from the robust list. [ tglx: Rewrote changelog, proper sizeof() based alignement check and add comment ] Fixes: 0771dfefc9e5 ("[PATCH] lightweight robust futexes: core") Signed-off-by: Chen Jie Signed-off-by: Thomas Gleixner Cc: Cc: Cc: Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/1552621478-119787-1-git-send-email-chenjie6@huawei.com Signed-off-by: Greg Kroah-Hartman --- kernel/futex.c | 4 ++++ 1 file changed, 4 insertions(+) --- a/kernel/futex.c +++ b/kernel/futex.c @@ -2897,6 +2897,10 @@ int handle_futex_death(u32 __user *uaddr { u32 uval, uninitialized_var(nval), mval; + /* Futex address must be 32bit aligned */ + if ((((unsigned long)uaddr) % sizeof(*uaddr)) != 0) + return -1; + retry: if (get_user(uval, uaddr)) return -1;