From patchwork Tue Apr 5 07:34:33 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: 556519 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 065D4C47080 for ; Tue, 5 Apr 2022 12:34:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1383303AbiDEMZ0 (ORCPT ); Tue, 5 Apr 2022 08:25:26 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46234 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1348675AbiDEKsF (ORCPT ); Tue, 5 Apr 2022 06:48:05 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 59A0F63BF0; Tue, 5 Apr 2022 03:27:20 -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 ams.source.kernel.org (Postfix) with ESMTPS id E3FC3B81B18; Tue, 5 Apr 2022 10:27:18 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 527A1C385A0; Tue, 5 Apr 2022 10:27:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1649154437; bh=izMv/LMDq16sbMxK8dWa52dHpvXUUl3PEqt/CPB1xl4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=xpslcnrkn5jN71mI9tgTGudtnm1dzUnK1+bRFc4a1204DUVbZx/9U39Q8Tci4h8+p UM3F7BwKL2oyl1PwbCO/FUAD1Bp4jqDGS9hWdBPpeF8/URn7jbxlhlXw2jWF2LYcny f/gQHogbQiym2fWAMenOAq7kbPXP9izHz8qNXLiY= 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 5.10 579/599] mm/usercopy: return 1 from hardened_usercopy __setup() handler Date: Tue, 5 Apr 2022 09:34:33 +0200 Message-Id: <20220405070316.073093929@linuxfoundation.org> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20220405070258.802373272@linuxfoundation.org> References: <20220405070258.802373272@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);