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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 4B133C433FE for ; Mon, 18 Apr 2022 14:08:29 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S244981AbiDROLE (ORCPT ); Mon, 18 Apr 2022 10:11:04 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51442 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1343996AbiDROIp (ORCPT ); Mon, 18 Apr 2022 10:08:45 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 60E3536B4B; Mon, 18 Apr 2022 06:10:40 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 4A31060EFC; Mon, 18 Apr 2022 13:10:21 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3C586C385A7; Mon, 18 Apr 2022 13:10:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1650287420; bh=QuH+eYlfumohtNKXemIHS8kzlJGvklyVCkz6jRqEVrA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=A9axYUrX1rG6wIOpFYYRUhqrrOR2fglF4JpoTzrEhDSbx16ymdh8YVlYZXY7bAKfl nT+f/6Ea4qc/8wRiYuNkl9B4vnLV+VMq1vn5wPT5IJZmLf7/Wtkkn7Au/rvSW2m1IU NGQgSGmjwr++H9mri+uadLeY48++2HXQd/dB00Go= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Randy Dunlap , Igor Zhbanov , Hugh Dickins , Andrew Morton , Linus Torvalds Subject: [PATCH 4.9 155/218] mm/mmap: return 1 from stack_guard_gap __setup() handler Date: Mon, 18 Apr 2022 14:13:41 +0200 Message-Id: <20220418121204.386709845@linuxfoundation.org> X-Mailer: git-send-email 2.35.3 In-Reply-To: <20220418121158.636999985@linuxfoundation.org> References: <20220418121158.636999985@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Randy Dunlap commit e6d094936988910ce6e8197570f2753898830081 upstream. __setup() handlers should return 1 if the command line option is handled and 0 if not (or maybe never return 0; it just pollutes init's environment). This prevents: Unknown kernel command line parameters \ "BOOT_IMAGE=/boot/bzImage-517rc5 stack_guard_gap=100", will be \ passed to user space. Run /sbin/init as init process with arguments: /sbin/init with environment: HOME=/ TERM=linux BOOT_IMAGE=/boot/bzImage-517rc5 stack_guard_gap=100 Return 1 to indicate that the boot option has been handled. Note that there is no warning message if someone enters: stack_guard_gap=anything_invalid and 'val' and stack_guard_gap are both set to 0 due to the use of simple_strtoul(). This could be improved by using kstrtoxxx() and checking for an error. It appears that having stack_guard_gap == 0 is valid (if unexpected) since using "stack_guard_gap=0" on the kernel command line does that. Link: https://lkml.kernel.org/r/20220222005817.11087-1-rdunlap@infradead.org Link: lore.kernel.org/r/64644a2f-4a20-bab3-1e15-3b2cdd0defe3@omprussia.ru Fixes: 1be7107fbe18e ("mm: larger stack guard gap, between vmas") Signed-off-by: Randy Dunlap Reported-by: Igor Zhbanov Cc: Hugh Dickins Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman --- mm/mmap.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/mm/mmap.c +++ b/mm/mmap.c @@ -2425,7 +2425,7 @@ static int __init cmdline_parse_stack_gu if (!*endptr) stack_guard_gap = val << PAGE_SHIFT; - return 0; + return 1; } __setup("stack_guard_gap=", cmdline_parse_stack_guard_gap);