From patchwork Thu Mar 13 10:17:02 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: AKASHI Takahiro X-Patchwork-Id: 26194 Return-Path: X-Original-To: linaro@patches.linaro.org Delivered-To: linaro@patches.linaro.org Received: from mail-ve0-f198.google.com (mail-ve0-f198.google.com [209.85.128.198]) by ip-10-151-82-157.ec2.internal (Postfix) with ESMTPS id 7D9D2206A0 for ; Thu, 13 Mar 2014 10:17:34 +0000 (UTC) Received: by mail-ve0-f198.google.com with SMTP id oz11sf1867649veb.9 for ; Thu, 13 Mar 2014 03:17:34 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:mime-version:delivered-to:from:to:cc:subject :date:message-id:in-reply-to:references:x-original-sender :x-original-authentication-results:precedence:mailing-list:list-id :list-post:list-help:list-archive:list-unsubscribe; bh=gqzVWxmHSDD+sIe9a3hxnafTvV1TW6gsO99wCXY2tyU=; b=bjejiVKQlbE+KsBd5K9CPxwgBuAKjmf1n2MkTkr5+F2h1gNVH8B/5fsnNq9n+TlEfY Aq+jTZuuELAxv+eX02ED7SNkdfARv3cGvRyrOpqDTPTkYwhMdPw/Mh5JlxzOMoUPqJah Tc8nxPtsl800QsMgF+JT3b/9lkx0KtmmMwBxHDIW5N8QCsyWjqSMs3aE3NqVK7SH+LVk 2hjtqMNtOjVTS9KehnrFE6GX8J+4AcF5UUc/uTb4wl+GCMN4LoAGG2yIblL3Lc0/lYSZ SX8XlpK68YPepCnzoVyzXTAGOYtnCZTHaySWFH2UfUz87jb5ynpT3c7Obe4MVfk6+PXG 8z9A== X-Gm-Message-State: ALoCoQmcQFvRVtIMdPI/X4+9euc3rRhcmdkYOns60WdEHs23qLpiG1MePhi2fXiT+0h9C/8B0v46 X-Received: by 10.58.170.6 with SMTP id ai6mr406760vec.7.1394705854296; Thu, 13 Mar 2014 03:17:34 -0700 (PDT) MIME-Version: 1.0 X-BeenThere: patchwork-forward@linaro.org Received: by 10.140.91.131 with SMTP id z3ls224811qgd.59.gmail; Thu, 13 Mar 2014 03:17:34 -0700 (PDT) X-Received: by 10.58.57.67 with SMTP id g3mr709209veq.3.1394705854162; Thu, 13 Mar 2014 03:17:34 -0700 (PDT) Received: from mail-ve0-f182.google.com (mail-ve0-f182.google.com [209.85.128.182]) by mx.google.com with ESMTPS id wm4si611512vcb.79.2014.03.13.03.17.34 for (version=TLSv1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Thu, 13 Mar 2014 03:17:34 -0700 (PDT) Received-SPF: neutral (google.com: 209.85.128.182 is neither permitted nor denied by best guess record for domain of patch+caf_=patchwork-forward=linaro.org@linaro.org) client-ip=209.85.128.182; Received: by mail-ve0-f182.google.com with SMTP id jw12so854209veb.27 for ; Thu, 13 Mar 2014 03:17:34 -0700 (PDT) X-Received: by 10.221.37.1 with SMTP id tc1mr134779vcb.32.1394705854050; Thu, 13 Mar 2014 03:17:34 -0700 (PDT) X-Forwarded-To: patchwork-forward@linaro.org X-Forwarded-For: patch@linaro.org patchwork-forward@linaro.org Delivered-To: patches@linaro.org Received: by 10.220.78.9 with SMTP id i9csp356041vck; Thu, 13 Mar 2014 03:17:33 -0700 (PDT) X-Received: by 10.68.215.40 with SMTP id of8mr1254335pbc.15.1394705853113; Thu, 13 Mar 2014 03:17:33 -0700 (PDT) Received: from mail-pa0-f50.google.com (mail-pa0-f50.google.com [209.85.220.50]) by mx.google.com with ESMTPS id pk2si1828055pbb.119.2014.03.13.03.17.32 for (version=TLSv1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Thu, 13 Mar 2014 03:17:33 -0700 (PDT) Received-SPF: neutral (google.com: 209.85.220.50 is neither permitted nor denied by best guess record for domain of takahiro.akashi@linaro.org) client-ip=209.85.220.50; Received: by mail-pa0-f50.google.com with SMTP id kq14so907680pab.23 for ; Thu, 13 Mar 2014 03:17:32 -0700 (PDT) X-Received: by 10.66.123.5 with SMTP id lw5mr1198122pab.83.1394705852740; Thu, 13 Mar 2014 03:17:32 -0700 (PDT) Received: from localhost.localdomain (KD182249091179.au-net.ne.jp. [182.249.91.179]) by mx.google.com with ESMTPSA id qh2sm7604887pab.13.2014.03.13.03.17.28 for (version=TLSv1.1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Thu, 13 Mar 2014 03:17:31 -0700 (PDT) From: AKASHI Takahiro To: wad@chromium.org, catalin.marinas@arm.com, will.deacon@arm.com, arndb@arndb.de Cc: dsaxena@linaro.org, linux-arm-kernel@lists.infradead.org, linaro-kernel@lists.linaro.org, linux-kernel@vger.kernel.org, patches@linaro.org, AKASHI Takahiro Subject: [PATCH v3 2/3] arm64: Add seccomp support Date: Thu, 13 Mar 2014 19:17:02 +0900 Message-Id: <1394705823-12465-3-git-send-email-takahiro.akashi@linaro.org> X-Mailer: git-send-email 1.8.3.2 In-Reply-To: <1394705823-12465-1-git-send-email-takahiro.akashi@linaro.org> References: <1393320025-2855-1-git-send-email-takahiro.akashi@linaro.org> <1394705823-12465-1-git-send-email-takahiro.akashi@linaro.org> X-Removed-Original-Auth: Dkim didn't pass. X-Original-Sender: takahiro.akashi@linaro.org X-Original-Authentication-Results: mx.google.com; spf=neutral (google.com: 209.85.128.182 is neither permitted nor denied by best guess record for domain of patch+caf_=patchwork-forward=linaro.org@linaro.org) smtp.mail=patch+caf_=patchwork-forward=linaro.org@linaro.org Precedence: list Mailing-list: list patchwork-forward@linaro.org; contact patchwork-forward+owners@linaro.org List-ID: X-Google-Group-Id: 836684582541 List-Post: , List-Help: , List-Archive: List-Unsubscribe: , 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 7ca6799..21b33f4 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -27,6 +27,7 @@ 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 @@ -229,6 +230,19 @@ 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 d10c637..be2bb4c 100644 --- a/arch/arm64/kernel/ptrace.c +++ b/arch/arm64/kernel/ptrace.c @@ -20,12 +20,14 @@ */ #include +#include #include #include #include #include #include #include +#include #include #include #include @@ -1067,6 +1069,10 @@ asmlinkage int syscall_trace_enter(struct pt_regs *regs) { unsigned long saved_reg; + if (secure_computing(regs->syscallno) == -1) + /* seccomp failures shouldn't expose any additional code. */ + return -EPERM; + if (test_thread_flag(TIF_SYSCALL_TRACE)) { /* * A scrach register (ip(r12) on AArch32, x7 on AArch64) is