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=-9.1 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,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 46728C282CE for ; Wed, 22 May 2019 19:35:07 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 1ABB22081C for ; Wed, 22 May 2019 19:35:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1558553707; bh=Xanzm7GxJ9VwcNbGFjjFvm6igLtC5BUZf9hHHr9HGyU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=A/WOlaSzjKvUEYyUxnwUCG6wm0hkAnDTK3FG4orkVauqwDdMkh+ye6l2exXPMBe8l DGsv5NJ6cuGijwOAlWWmDEzPCdLHqZxDrpP5Y2cMTsmA1opwhrQGdibCRni2adOqf8 qjTcEszSm/i96wBHq33UnGLPl5NmsefFg59ckp0k= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387511AbfEVTfG (ORCPT ); Wed, 22 May 2019 15:35:06 -0400 Received: from mail.kernel.org ([198.145.29.99]:54764 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2387472AbfEVTbR (ORCPT ); Wed, 22 May 2019 15:31:17 -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 ED0512177E; Wed, 22 May 2019 19:31:15 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1558553476; bh=Xanzm7GxJ9VwcNbGFjjFvm6igLtC5BUZf9hHHr9HGyU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=LLh8PRMpLNckrCOyR6uThFdqBJGxYuYTmPA44Wq2JlImxS5w5qQL1swAw2OgNRDoF RjQBT8N28oHB6Oeogvt79h5GVtUc4RScmZLYg4fRH0qnH0yBrkO1KbfCgKr9kT5WBJ droA0aul9Trt/WXhw8fbrWrrbsLRUwGGy4mheoOI= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Peter Zijlstra , Randy Dunlap , Linus Torvalds , Thomas Gleixner , luto@kernel.org, Ingo Molnar , Sasha Levin Subject: [PATCH AUTOSEL 4.9 036/114] mm/uaccess: Use 'unsigned long' to placate UBSAN warnings on older GCC versions Date: Wed, 22 May 2019 15:28:59 -0400 Message-Id: <20190522193017.26567-36-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190522193017.26567-1-sashal@kernel.org> References: <20190522193017.26567-1-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: Peter Zijlstra [ Upstream commit 29da93fea3ea39ab9b12270cc6be1b70ef201c9e ] Randy reported objtool triggered on his (GCC-7.4) build: lib/strncpy_from_user.o: warning: objtool: strncpy_from_user()+0x315: call to __ubsan_handle_add_overflow() with UACCESS enabled lib/strnlen_user.o: warning: objtool: strnlen_user()+0x337: call to __ubsan_handle_sub_overflow() with UACCESS enabled This is due to UBSAN generating signed-overflow-UB warnings where it should not. Prior to GCC-8 UBSAN ignored -fwrapv (which the kernel uses through -fno-strict-overflow). Make the functions use 'unsigned long' throughout. Reported-by: Randy Dunlap Signed-off-by: Peter Zijlstra (Intel) Acked-by: Randy Dunlap # build-tested Acked-by: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: luto@kernel.org Link: http://lkml.kernel.org/r/20190424072208.754094071@infradead.org Signed-off-by: Ingo Molnar Signed-off-by: Sasha Levin --- lib/strncpy_from_user.c | 5 +++-- lib/strnlen_user.c | 4 ++-- 2 files changed, 5 insertions(+), 4 deletions(-) diff --git a/lib/strncpy_from_user.c b/lib/strncpy_from_user.c index 7e35fc450c5bb..5a07f19059c36 100644 --- a/lib/strncpy_from_user.c +++ b/lib/strncpy_from_user.c @@ -22,10 +22,11 @@ * hit it), 'max' is the address space maximum (and we return * -EFAULT if we hit it). */ -static inline long do_strncpy_from_user(char *dst, const char __user *src, long count, unsigned long max) +static inline long do_strncpy_from_user(char *dst, const char __user *src, + unsigned long count, unsigned long max) { const struct word_at_a_time constants = WORD_AT_A_TIME_CONSTANTS; - long res = 0; + unsigned long res = 0; /* * Truncate 'max' to the user-specified limit, so that diff --git a/lib/strnlen_user.c b/lib/strnlen_user.c index 8e105ed4df12b..9ff4f3bbb1aae 100644 --- a/lib/strnlen_user.c +++ b/lib/strnlen_user.c @@ -27,7 +27,7 @@ static inline long do_strnlen_user(const char __user *src, unsigned long count, unsigned long max) { const struct word_at_a_time constants = WORD_AT_A_TIME_CONSTANTS; - long align, res = 0; + unsigned long align, res = 0; unsigned long c; /* @@ -41,7 +41,7 @@ static inline long do_strnlen_user(const char __user *src, unsigned long count, * Do everything aligned. But that means that we * need to also expand the maximum.. */ - align = (sizeof(long) - 1) & (unsigned long)src; + align = (sizeof(unsigned long) - 1) & (unsigned long)src; src -= align; max += align; -- 2.20.1