From patchwork Sat Mar 15 05:50:04 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: AKASHI Takahiro X-Patchwork-Id: 3836511 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 46D87BF540 for ; Sat, 15 Mar 2014 05:52:18 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 5D0962034E for ; Sat, 15 Mar 2014 05:52:17 +0000 (UTC) Received: from casper.infradead.org (casper.infradead.org [85.118.1.10]) (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 4F85720340 for ; Sat, 15 Mar 2014 05:52:16 +0000 (UTC) Received: from merlin.infradead.org ([2001:4978:20e::2]) by casper.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1WOhVO-0005xV-LA; Sat, 15 Mar 2014 05:51:35 +0000 Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1WOhVB-00006D-54; Sat, 15 Mar 2014 05:51:21 +0000 Received: from mail-pd0-f178.google.com ([209.85.192.178]) by merlin.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1WOhUw-0008TQ-EE for linux-arm-kernel@lists.infradead.org; Sat, 15 Mar 2014 05:51:14 +0000 Received: by mail-pd0-f178.google.com with SMTP id x10so3406443pdj.23 for ; Fri, 14 Mar 2014 22:50:43 -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=+Mk9O81odOUJDAk4SDE45/DqisdfswmK5cHK47+9bvQ=; b=LDO3TYMxEHaVUCVaKhkSaRuDLLYj6DTnkezzcMJc6cyCv0XA6qN/byqDoGIF0Qcfwh ZCaW7Fa+7vIOuUNGJZwLQ0z0ZHgW3UzLgDJT+x4/jYWvIlnNlZIE2b6GA9KGIVqP/drc 1qV++0FenIq5ALMLCdN+aNyAJ4hyol9bG78vYAizb6IRiB4GMXZIRrP3NmAyHTsOGMbU /e6OSQcNVm9kRsrXogVsK4ulbxx1a5+dA0MD5MgCNdoQb5ZuBzeXtGzj8IIgRzYa1XeR 98J5XF+hrrAx62SEQm8nQGiBG9k9bdkJMkcV+LWCuyL7qlmGegOMONeqRfGoI47KYPd4 lb2w== X-Gm-Message-State: ALoCoQlavg9pVApJX/wG8YEV8vD1uKPV/e/oGIrqPNbn5IsjY0xliMXHT0j1M6Xu3SHtIkKVvD3r X-Received: by 10.66.153.80 with SMTP id ve16mr13206261pab.143.1394862643521; Fri, 14 Mar 2014 22:50:43 -0700 (PDT) Received: from localhost.localdomain (pdddd29.tkyoac00.ap.so-net.ne.jp. [218.221.221.41]) by mx.google.com with ESMTPSA id ha11sm22375393pbd.17.2014.03.14.22.50.38 for (version=TLSv1.1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Fri, 14 Mar 2014 22:50:41 -0700 (PDT) From: AKASHI Takahiro To: wad@chromium.org, catalin.marinas@arm.com, will.deacon@arm.com, arndb@arndb.de Subject: [PATCH_v4 2/2] arm64: Add seccomp support Date: Sat, 15 Mar 2014 14:50:04 +0900 Message-Id: <1394862604-29105-3-git-send-email-takahiro.akashi@linaro.org> X-Mailer: git-send-email 1.8.3.2 In-Reply-To: <1394862604-29105-1-git-send-email-takahiro.akashi@linaro.org> References: <1394705823-12465-1-git-send-email-takahiro.akashi@linaro.org> <1394862604-29105-1-git-send-email-takahiro.akashi@linaro.org> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20140315_015106_698165_34618932 X-CRM114-Status: GOOD ( 16.83 ) X-Spam-Score: -1.9 (-) Cc: linaro-kernel@lists.linaro.org, patches@linaro.org, linux-kernel@vger.kernel.org, AKASHI Takahiro , dsaxena@linaro.org, linux-arm-kernel@lists.infradead.org X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.15 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=-4.2 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_MED, T_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 it returns non-zero, we should stop further handling. Then that system call may eventually fail, be trapped or the process itself be killed depending on loaded rules. In this case, syscall_trace_enter() returns a dedicated value in order to skip a normal syscall table lookup because a seccomp rule may have already overridden errno. 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/entry.S | 4 ++++ arch/arm64/kernel/ptrace.c | 6 ++++++ 5 files changed, 52 insertions(+) create mode 100644 arch/arm64/include/asm/seccomp.h diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index 7c1f8c7..d5167d6 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -28,6 +28,7 @@ config ARM64 select HARDIRQS_SW_RESEND select HAVE_ARCH_AUDITSYSCALL select HAVE_ARCH_JUMP_LABEL + select HAVE_ARCH_SECCOMP_FILTER select HAVE_ARCH_TRACEHOOK select HAVE_C_RECORDMCOUNT select HAVE_DEBUG_BUGVERBOSE @@ -230,6 +231,19 @@ config HAVE_ARCH_TRANSPARENT_HUGEPAGE 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 04f5d22..28bf882 100644 --- a/arch/arm64/include/asm/unistd.h +++ b/arch/arm64/include/asm/unistd.h @@ -30,6 +30,9 @@ * 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/entry.S b/arch/arm64/kernel/entry.S index f06ee35..6ef266a 100644 --- a/arch/arm64/kernel/entry.S +++ b/arch/arm64/kernel/entry.S @@ -650,6 +650,10 @@ ENDPROC(el0_svc) __sys_trace: mov x0, sp bl syscall_trace_enter +#ifdef CONFIG_SECCOMP + cmp w0, #-EPERM // check seccomp result + b.eq ret_to_user // -EPERM means 'rejected' +#endif adr lr, __sys_trace_return // return address uxtw scno, w0 // syscall number (possibly new) mov x1, sp // pointer to regs diff --git a/arch/arm64/kernel/ptrace.c b/arch/arm64/kernel/ptrace.c index f9e1339..bb89fa3 100644 --- a/arch/arm64/kernel/ptrace.c +++ b/arch/arm64/kernel/ptrace.c @@ -21,12 +21,14 @@ #include #include +#include #include #include #include #include #include #include +#include #include #include #include @@ -1093,6 +1095,10 @@ static void tracehook_report_syscall(struct pt_regs *regs, asmlinkage int syscall_trace_enter(struct pt_regs *regs) { + if (secure_computing(regs->syscallno) == -1) + /* seccomp failures shouldn't expose any additional code. */ + return -EPERM; + if (test_thread_flag(TIF_SYSCALL_TRACE)) tracehook_report_syscall(regs, PTRACE_SYSCALL_ENTER);