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=-8.8 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,SPF_HELO_NONE,SPF_PASS autolearn=unavailable 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 E11C3C433E5 for ; Wed, 15 Jul 2020 06:42:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B09FC2068F for ; Wed, 15 Jul 2020 06:42:52 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="SI0lmEAh" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728785AbgGOGmv (ORCPT ); Wed, 15 Jul 2020 02:42:51 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35738 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727931AbgGOGmv (ORCPT ); Wed, 15 Jul 2020 02:42:51 -0400 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 21059C061755; Tue, 14 Jul 2020 23:42:51 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=iiqlg7cTMEEh/98unAkrIf26PUMXeeNcPlUx1yAhp14=; b=SI0lmEAhe6+jdUykJJbbeGfMrp drBSmZEhyCV/54C6ocS8LX4JV4aUnx0mzv66YzEMI4Dnt2JVYFYr7InMRqdNkrm4M1gPToMPhwJzM BdVI+QwIgit2XFWYHGyM7+oWVfyH9G6CNJBFQv5OdNvN3UxsCHbuQkLB9nwH32xrZ2C6xTMnvsuiA Wu02DiIjtAWMnXJblrZGTKRLHU2CHMfaM/zVRf0gynSmHTMmGjqbyEM1ZZ4dsewDrfLGEmDV+AHdS 6/BS9UiJmePMczg76GSwOX30yDfmGKjUDGhkVQpWVg5YYjmqIPJntXGXpSDiZhBnqSK3t9FawFunX F8ciAzTA==; Received: from hch by casper.infradead.org with local (Exim 4.92.3 #3 (Red Hat Linux)) id 1jvb7x-0001AT-0R; Wed, 15 Jul 2020 06:42:49 +0000 Date: Wed, 15 Jul 2020 07:42:48 +0100 From: Christoph Hellwig To: Kees Cook Cc: "Eric W. Biederman" , linux-kernel@vger.kernel.org, Linus Torvalds , Andy Lutomirski , "H. Peter Anvin" , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Al Viro , Luis Chamberlain , linux-fsdevel@vger.kernel.org, Tetsuo Handa , linux-security-module@vger.kernel.org, "Serge E. Hallyn" , James Morris , Kentaro Takeda , Casey Schaufler , John Johansen , Christoph Hellwig Subject: Re: [PATCH 7/7] exec: Implement kernel_execve Message-ID: <20200715064248.GH32470@infradead.org> References: <871rle8bw2.fsf@x220.int.ebiederm.org> <87wo365ikj.fsf@x220.int.ebiederm.org> <202007141446.A72A4437C@keescook> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <202007141446.A72A4437C@keescook> X-SRS-Rewrite: SMTP reverse-path rewritten from by casper.infradead.org. See http://www.infradead.org/rpr.html Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Jul 14, 2020 at 02:49:23PM -0700, Kees Cook wrote: > On Tue, Jul 14, 2020 at 08:31:40AM -0500, Eric W. Biederman wrote: > > +static int count_strings_kernel(const char *const *argv) > > +{ > > + int i; > > + > > + if (!argv) > > + return 0; > > + > > + for (i = 0; argv[i]; ++i) { > > + if (i >= MAX_ARG_STRINGS) > > + return -E2BIG; > > + if (fatal_signal_pending(current)) > > + return -ERESTARTNOHAND; > > + cond_resched(); > > + } > > + return i; > > +} > > I notice count() is only ever called with MAX_ARG_STRINGS. Perhaps > refactor that too? (And maybe rename it to count_strings_user()?) Liks this? http://git.infradead.org/users/hch/misc.git/commitdiff/35a3129dab5b712b018c30681d15de42d9509731