| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Message-Id: <1416977391-24231-7-git-send-email-takahiro.akashi@linaro.org>
Date: Wed, 26 Nov 2014 13:49:51 +0900
From: AKASHI Takahiro <takahiro.akashi@...aro.org>
To: keescook@...omium.org, catalin.marinas@....com, will.deacon@....com
Cc: dsaxena@...aro.org, arndb@...db.de,
linux-arm-kernel@...ts.infradead.org,
linaro-kernel@...ts.linaro.org, linux-kernel@...r.kernel.org,
AKASHI Takahiro <takahiro.akashi@...aro.org>
Subject: [PATCH v9 6/6] arm64: add seccomp support
secure_computing() is called first in syscall_trace_enter() so that
a system call will be aborted quickly without doing succeeding syscall
tracing if seccomp rules want to deny that system call.
On compat task, syscall numbers for system calls allowed in seccomp mode 1
are different from those on normal tasks, and so _NR_seccomp_xxx_32's need
to be redefined.
Signed-off-by: AKASHI Takahiro <takahiro.akashi@...aro.org>
---
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 9532f8d..f495d3c 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -37,6 +37,7 @@ 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_BPF_JIT
select HAVE_C_RECORDMCOUNT
@@ -345,6 +346,19 @@ 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 <takahiro.akashi@...aro.org>
+ *
+ * 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 <asm/unistd.h>
+
+#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 <asm-generic/seccomp.h>
+
+#endif /* _ASM_SECCOMP_H */
diff --git a/arch/arm64/include/asm/unistd.h b/arch/arm64/include/asm/unistd.h
index 6d2bf41..49c9aef 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 8b98781..d894eab 100644
--- a/arch/arm64/kernel/ptrace.c
+++ b/arch/arm64/kernel/ptrace.c
@@ -27,6 +27,7 @@
#include <linux/smp.h>
#include <linux/ptrace.h>
#include <linux/user.h>
+#include <linux/seccomp.h>
#include <linux/security.h>
#include <linux/init.h>
#include <linux/signal.h>
@@ -1149,6 +1150,10 @@ static void tracehook_report_syscall(struct pt_regs *regs,
asmlinkage int syscall_trace_enter(struct pt_regs *regs)
{
+ /* Do the secure computing check first; failures should be fast. */
+ if (secure_computing() == -1)
+ return -1;
+
if (test_thread_flag(TIF_SYSCALL_TRACE))
tracehook_report_syscall(regs, PTRACE_SYSCALL_ENTER);
--
1.7.9.5
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
Powered by blists - more mailing lists