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=DKIM_SIGNED,DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS, URIBL_BLOCKED,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 613CEC43381 for ; Tue, 26 Mar 2019 06:31:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 2F58F20863 for ; Tue, 26 Mar 2019 06:31:46 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1553581906; bh=/TUrN4y3ylhaLve7jrAYIkqMu/k6ee2UyMWHnkM23xQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=u1h39CrtX/wCJbgwJ4twBa3wZ/UETtIiEAu9OIfWNAg6qqvmAF6xzt2Y1CTTMStqP ryvjHybgFHiTVTAU7rJqGsuFe6f5jHSZlFMepQggWK6gCqSk/PLQL5WEzADctnlcha fJg2x789zDQP6D8ESS/myCGNoGTk6+EOpjnonaLM= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725535AbfCZGbo (ORCPT ); Tue, 26 Mar 2019 02:31:44 -0400 Received: from mail.kernel.org ([198.145.29.99]:41090 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731108AbfCZGbm (ORCPT ); Tue, 26 Mar 2019 02:31:42 -0400 Received: from localhost (unknown [104.132.152.111]) (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 ADAC720866; Tue, 26 Mar 2019 06:31:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1553581901; bh=/TUrN4y3ylhaLve7jrAYIkqMu/k6ee2UyMWHnkM23xQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=FrvuVVVXTfSjS0uLYhArFjwxjwaVwlmAtkosgzbP7DmATSoLk7HmhRMcQqOyxaYDC mdJxQlv91zjltKoYJXtzhJk5OCUgoD6tFRvz6G/x/Vf/SQmW1n6IJ4gFjyXg4UT3EH mXqIGa1xbPmrz2H4Hd/r24DeD42F5Y+ksioj7UWQ= 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 4.9 09/30] futex: Ensure that futex address is aligned in handle_futex_death() Date: Tue, 26 Mar 2019 15:29:48 +0900 Message-Id: <20190326042607.894047733@linuxfoundation.org> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20190326042607.558087893@linuxfoundation.org> References: <20190326042607.558087893@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: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org 4.9-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 @@ -3110,6 +3110,10 @@ 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;