From patchwork Tue Jul 22 09:14:59 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: AKASHI Takahiro X-Patchwork-Id: 4600331 Return-Path: X-Original-To: patchwork-linux-arm@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork2.web.kernel.org (Postfix) with ESMTP id 2595DC0514 for ; Tue, 22 Jul 2014 09:19:15 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 399D020145 for ; Tue, 22 Jul 2014 09:19:14 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.9]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id C18BE200E7 for ; Tue, 22 Jul 2014 09:19:12 +0000 (UTC) Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1X9WBs-0007we-KX; Tue, 22 Jul 2014 09:16:56 +0000 Received: from mail-pd0-f176.google.com ([209.85.192.176]) by bombadil.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1X9WBo-0007Zf-6s for linux-arm-kernel@lists.infradead.org; Tue, 22 Jul 2014 09:16:52 +0000 Received: by mail-pd0-f176.google.com with SMTP id y10so10762936pdj.7 for ; Tue, 22 Jul 2014 02:16:31 -0700 (PDT) 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=/J+rYDMEfewDXTvZC2/mlCBHHxMip+0aDppZxEmuCi0=; b=l6sGIkqQHPWbirtG55xO7gqw7mTWcEAxlUNUCN9b6o6q4jDwicIaJ/c96EfTWgCuLV vo1Vzr1+1FPZR02qrJHoUkqbDA30LlmE8xkIX3s1Akn6Sx1GduAGD+s9B1KNP/3f3Wye x/Mbz5cl0e0oFsLs890VnOpYBJ3ow8EmHliSxB/b3dYYFohcJ09DkwLVzxrRSX/u6DYF iIjURVDZW0MilbeO9H8wb7WN6orfTEORa5OaD/IxZXhoE3txKoQ64uS7SOlwJ2kRlk7O pQh1C0BtaDrdQusIIXOds7j7n00PJbOI0vkeypN0Hn9qU+FDhjRKN5QUbJwqUEm9hVzR 4NMg== X-Gm-Message-State: ALoCoQnJ/CNcIIOhv+dnoOpbIeW7STtemEdC5WK1e/Qwr9T1QRiXyY2dyxTdyWKGjDYbMNxSwsiK X-Received: by 10.70.96.38 with SMTP id dp6mr9980458pdb.136.1406020588551; Tue, 22 Jul 2014 02:16:28 -0700 (PDT) Received: from localhost.localdomain (KD182249094163.au-net.ne.jp. [182.249.94.163]) by mx.google.com with ESMTPSA id v1sm12071461pbs.1.2014.07.22.02.16.04 for (version=TLSv1.2 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Tue, 22 Jul 2014 02:16:27 -0700 (PDT) From: AKASHI Takahiro To: wad@chromium.org, catalin.marinas@arm.com, will.deacon@arm.com, keescook@chromium.org Subject: [PATCH v5 3/3] arm64: Add seccomp support Date: Tue, 22 Jul 2014 18:14:59 +0900 Message-Id: <1406020499-5537-4-git-send-email-takahiro.akashi@linaro.org> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1406020499-5537-1-git-send-email-takahiro.akashi@linaro.org> References: <1406020499-5537-1-git-send-email-takahiro.akashi@linaro.org> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20140722_021652_304439_778A2A24 X-CRM114-Status: GOOD ( 14.57 ) X-Spam-Score: -0.7 (/) Cc: AKASHI Takahiro , dsaxena@linaro.org, linaro-kernel@lists.linaro.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.18-1 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Spam-Status: No, score=-1.9 required=5.0 tests=BAYES_00,RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP secure_computing() should always be called first in syscall_trace_enter(). If secure_computing() returns -1, we should stop further handling. Then that system call may eventually fail with a specified return value (errno), be trapped or the process itself be killed depending on loaded rules. In these cases, syscall_trace_enter() also returns -1, that results in skiping a normal syscall handling as well as syscall_trace_exit(). Signed-off-by: AKASHI Takahiro --- arch/arm64/Kconfig | 14 ++++++++++++++ arch/arm64/include/asm/seccomp.h | 25 +++++++++++++++++++++++++ arch/arm64/include/asm/unistd.h | 3 +++ arch/arm64/kernel/ptrace.c | 5 +++++ 4 files changed, 47 insertions(+) create mode 100644 arch/arm64/include/asm/seccomp.h diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index 3a18571..eeac003 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -32,6 +32,7 @@ config ARM64 select HAVE_ARCH_AUDITSYSCALL select HAVE_ARCH_JUMP_LABEL select HAVE_ARCH_KGDB + select HAVE_ARCH_SECCOMP_FILTER select HAVE_ARCH_TRACEHOOK select HAVE_C_RECORDMCOUNT select HAVE_DEBUG_BUGVERBOSE @@ -259,6 +260,19 @@ config ARCH_HAS_CACHE_LINE_SIZE source "mm/Kconfig" +config SECCOMP + bool "Enable seccomp to safely compute untrusted bytecode" + ---help--- + This kernel feature is useful for number crunching applications + that may need to compute untrusted bytecode during their + execution. By using pipes or other transports made available to + the process as file descriptors supporting the read/write + syscalls, it's possible to isolate those applications in + their own address space using seccomp. Once seccomp is + enabled via prctl(PR_SET_SECCOMP), it cannot be disabled + and the task is only allowed to execute a few safe syscalls + defined by each seccomp mode. + config XEN_DOM0 def_bool y depends on XEN diff --git a/arch/arm64/include/asm/seccomp.h b/arch/arm64/include/asm/seccomp.h new file mode 100644 index 0000000..c76fac9 --- /dev/null +++ b/arch/arm64/include/asm/seccomp.h @@ -0,0 +1,25 @@ +/* + * arch/arm64/include/asm/seccomp.h + * + * Copyright (C) 2014 Linaro Limited + * Author: AKASHI Takahiro + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ +#ifndef _ASM_SECCOMP_H +#define _ASM_SECCOMP_H + +#include + +#ifdef CONFIG_COMPAT +#define __NR_seccomp_read_32 __NR_compat_read +#define __NR_seccomp_write_32 __NR_compat_write +#define __NR_seccomp_exit_32 __NR_compat_exit +#define __NR_seccomp_sigreturn_32 __NR_compat_rt_sigreturn +#endif /* CONFIG_COMPAT */ + +#include + +#endif /* _ASM_SECCOMP_H */ diff --git a/arch/arm64/include/asm/unistd.h b/arch/arm64/include/asm/unistd.h index c980ab7..729c155 100644 --- a/arch/arm64/include/asm/unistd.h +++ b/arch/arm64/include/asm/unistd.h @@ -31,6 +31,9 @@ * Compat syscall numbers used by the AArch64 kernel. */ #define __NR_compat_restart_syscall 0 +#define __NR_compat_exit 1 +#define __NR_compat_read 3 +#define __NR_compat_write 4 #define __NR_compat_sigreturn 119 #define __NR_compat_rt_sigreturn 173 diff --git a/arch/arm64/kernel/ptrace.c b/arch/arm64/kernel/ptrace.c index 100d7d1..e477f6f 100644 --- a/arch/arm64/kernel/ptrace.c +++ b/arch/arm64/kernel/ptrace.c @@ -28,6 +28,7 @@ #include #include #include +#include #include #include #include @@ -1115,6 +1116,10 @@ asmlinkage int syscall_trace_enter(struct pt_regs *regs) saved_x0 = regs->regs[0]; saved_x8 = regs->regs[8]; + if (secure_computing(regs->syscallno) == -1) + /* seccomp failures shouldn't expose any additional code. */ + return -1; + if (test_thread_flag(TIF_SYSCALL_TRACE)) tracehook_report_syscall(regs, PTRACE_SYSCALL_ENTER);