From patchwork Thu Jun 9 21:01:57 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kees Cook X-Patchwork-Id: 9167937 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 420DB607DA for ; Thu, 9 Jun 2016 21:04:58 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 1224528359 for ; Thu, 9 Jun 2016 21:04:58 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 065A62835F; Thu, 9 Jun 2016 21:04:58 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.8 required=2.0 tests=BAYES_00,DKIM_SIGNED, RCVD_IN_DNSWL_HI,T_DKIM_INVALID autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 3203328359 for ; Thu, 9 Jun 2016 21:04:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752506AbcFIVDw (ORCPT ); Thu, 9 Jun 2016 17:03:52 -0400 Received: from mail-pf0-f175.google.com ([209.85.192.175]:34757 "EHLO mail-pf0-f175.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752086AbcFIVCe (ORCPT ); Thu, 9 Jun 2016 17:02:34 -0400 Received: by mail-pf0-f175.google.com with SMTP id 62so16361573pfd.1 for ; Thu, 09 Jun 2016 14:02:34 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=hsne7rjptpK2v5g2LzbrLT5o1W9sSkv6Twx8ZgIqYAA=; b=Mdt5E4Imll7KXY0i/yXM6cWPT0062qz75ej8IxKH2fSyyd8oNS1EVlNh2pPjqnpnt2 y6fxJa9pHFNnJfNxb6bOuSqXYzjyGDKDpdM111o3LINQvnfhR1npuC340cZdTd9qm9OC IBoKwuYf1bfTu4sQqM7kNLoXzPJakN4vrW1tU= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=hsne7rjptpK2v5g2LzbrLT5o1W9sSkv6Twx8ZgIqYAA=; b=ZOHwmm0rIqdzELGtVPMYghAHov5LcQMxkSdgksYaipAZ+Q/Egbk/OhKy9wLUEtsL7m mEG2Zv89j3a9WTD0rVgYVmyl0TKQpXNG8kiqdD2szhh4b9eqyVvBEEEubdo9lImyuSb/ uC7Z+87rtYmhaxrpYb8D0ZmnVQF7MBWOPs0sHU1ytdazOeJmO4r3t8zQicpllvsCp/tb UdTSdLCvkvsu0OnpsyrHVKZjD0OZaZAI+y3iAAf+kyfrv1ilTjO0v/8NI0j2NyVb+6fz gch7uZea1dlZoQXpu6gN+e+CS5ZbQ7GXnjMg8otJNUu6bly7OYz+l5HiFhXhIa1aM4zi HJqw== X-Gm-Message-State: ALyK8tKEWCraog5otP9ch3CBFkSOW+e7pgdqhhl5TeGphHuj0HbX0mCALoOD7g6TDsydvC9F X-Received: by 10.98.8.91 with SMTP id c88mr6448526pfd.57.1465506148864; Thu, 09 Jun 2016 14:02:28 -0700 (PDT) Received: from www.outflux.net ([2002:ada4:7085:0:ae16:2dff:fe07:4fb6]) by smtp.gmail.com with ESMTPSA id zn12sm12215972pab.14.2016.06.09.14.02.26 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 09 Jun 2016 14:02:27 -0700 (PDT) From: Kees Cook To: linux-kernel@vger.kernel.org Cc: Kees Cook , Russell King , linux-arm-kernel@lists.infradead.org, Andy Lutomirski , Benjamin Herrenschmidt , Catalin Marinas , Chris Metcalf , Heiko Carstens , Helge Deller , "James E.J. Bottomley" , James Hogan , Jeff Dike , linux-arch@vger.kernel.org, linux-mips@linux-mips.org, linux-parisc@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-s390@vger.kernel.org, "Maciej W. Rozycki" , Mark Rutland , Martin Schwidefsky , Michael Ellerman , Paul Mackerras , Ralf Baechle , Richard Weinberger , user-mode-linux-devel@lists.sourceforge.net, Will Deacon , x86@kernel.org Subject: [PATCH 07/14] arm/ptrace: run seccomp after ptrace Date: Thu, 9 Jun 2016 14:01:57 -0700 Message-Id: <1465506124-21866-8-git-send-email-keescook@chromium.org> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1465506124-21866-1-git-send-email-keescook@chromium.org> References: <1465506124-21866-1-git-send-email-keescook@chromium.org> Sender: linux-parisc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-parisc@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Close the hole where ptrace can change a syscall out from under seccomp. Signed-off-by: Kees Cook Cc: Russell King Cc: linux-arm-kernel@lists.infradead.org --- arch/arm/kernel/ptrace.c | 11 ++++++----- 1 file changed, 6 insertions(+), 5 deletions(-) diff --git a/arch/arm/kernel/ptrace.c b/arch/arm/kernel/ptrace.c index ad5e90ab165c..dc7b372872ff 100644 --- a/arch/arm/kernel/ptrace.c +++ b/arch/arm/kernel/ptrace.c @@ -932,18 +932,19 @@ asmlinkage int syscall_trace_enter(struct pt_regs *regs, int scno) { current_thread_info()->syscall = scno; - /* Do the secure computing check first; failures should be fast. */ + if (test_thread_flag(TIF_SYSCALL_TRACE)) + tracehook_report_syscall(regs, PTRACE_SYSCALL_ENTER); + + /* Do seccomp after ptrace; syscall may have changed. */ #ifdef CONFIG_HAVE_ARCH_SECCOMP_FILTER if (secure_computing(NULL) == -1) return -1; #else /* XXX: remove this once OABI gets fixed */ - secure_computing_strict(scno); + secure_computing_strict(current_thread_info()->syscall); #endif - if (test_thread_flag(TIF_SYSCALL_TRACE)) - tracehook_report_syscall(regs, PTRACE_SYSCALL_ENTER); - + /* Tracer or seccomp may have changed syscall. */ scno = current_thread_info()->syscall; if (test_thread_flag(TIF_SYSCALL_TRACEPOINT))