From patchwork Thu Apr 14 13:12:20 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg Kroah-Hartman X-Patchwork-Id: 561575 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 59689C433F5 for ; Thu, 14 Apr 2022 14:03:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239156AbiDNOFN (ORCPT ); Thu, 14 Apr 2022 10:05:13 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34706 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1346980AbiDNN6K (ORCPT ); Thu, 14 Apr 2022 09:58:10 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3454DB6444; Thu, 14 Apr 2022 06:48:25 -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 C554D61D68; Thu, 14 Apr 2022 13:48:24 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id D28E4C385A1; Thu, 14 Apr 2022 13:48:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1649944104; bh=izMv/LMDq16sbMxK8dWa52dHpvXUUl3PEqt/CPB1xl4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=SzzIx2BcGaMv+EScwCjs2cQlRseb3lzZI70Pe+WiPVZKQBD5gbWgNI9JRGuwz7jEZ mW8byoTYLdVoJNlxJamFcybJm0Wo/tTKnBpyjZs0l0sM6Z5iYnhsC0EKNRYRpfc3ku w1ra2qwNRKlMJc1E5cTEw5/HoGfYnWc0hn7SRaqI= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Randy Dunlap , Igor Zhbanov , Chris von Recklinghausen , Kees Cook , Andrew Morton , Linus Torvalds Subject: [PATCH 5.4 355/475] mm/usercopy: return 1 from hardened_usercopy __setup() handler Date: Thu, 14 Apr 2022 15:12:20 +0200 Message-Id: <20220414110905.016570272@linuxfoundation.org> X-Mailer: git-send-email 2.35.2 In-Reply-To: <20220414110855.141582785@linuxfoundation.org> References: <20220414110855.141582785@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Randy Dunlap commit 05fe3c103f7e6b8b4fca8a7001dfc9ed4628085b 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 hardened_usercopy=off", 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 hardened_usercopy=off or hardened_usercopy=on but when "hardened_usercopy=foo" is used, there is no Unknown kernel command line parameter. Return 1 to indicate that the boot option has been handled. Print a warning if strtobool() returns an error on the option string, but do not mark this as in unknown command line option and do not cause init's environment to be polluted with this string. Link: https://lkml.kernel.org/r/20220222034249.14795-1-rdunlap@infradead.org Link: lore.kernel.org/r/64644a2f-4a20-bab3-1e15-3b2cdd0defe3@omprussia.ru Fixes: b5cb15d9372ab ("usercopy: Allow boot cmdline disabling of hardening") Signed-off-by: Randy Dunlap Reported-by: Igor Zhbanov Acked-by: Chris von Recklinghausen Cc: Kees Cook Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman --- mm/usercopy.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) --- a/mm/usercopy.c +++ b/mm/usercopy.c @@ -294,7 +294,10 @@ static bool enable_checks __initdata = t static int __init parse_hardened_usercopy(char *str) { - return strtobool(str, &enable_checks); + if (strtobool(str, &enable_checks)) + pr_warn("Invalid option string for hardened_usercopy: '%s'\n", + str); + return 1; } __setup("hardened_usercopy=", parse_hardened_usercopy);