From: Thomas Garnier <thgarnie@google.com>
To: "Martin Schwidefsky" <schwidefsky@de.ibm.com>,
"Heiko Carstens" <heiko.carstens@de.ibm.com>,
"David Howells" <dhowells@redhat.com>,
"Arnd Bergmann" <arnd@arndb.de>,
"Dave Hansen" <dave.hansen@intel.com>,
"Al Viro" <viro@zeniv.linux.org.uk>,
"Thomas Gleixner" <tglx@linutronix.de>,
"René Nyffenegger" <mail@renenyffenegger.ch>,
"Thomas Garnier" <thgarnie@google.com>,
"Andrew Morton" <akpm@linux-foundation.org>,
"Paul E . McKenney" <paulmck@linux.vnet.ibm.com>,
"Ingo Molnar" <mingo@kernel.org>,
"Oleg Nesterov" <oleg@redhat.com>,
"Pavel Tikhomirov" <ptikhomirov@virtuozzo.com>,
"Stephen Smalley" <sds@tycho.nsa.gov>,
"Ingo Molnar" <mingo@redhat.com>,
"H . Peter Anvin" <hpa@zytor.com>,
"Andy Lutomirski" <luto@kernel.org>,
"Paolo Bonzini" <pbonzini@redhat.com>,
"Rik van Riel" <riel@redhat.com>,
"Kees Cook" <keescook@chromium.org>,
"Josh Poimboeuf" <jpoimboe@redhat.com>, "Borislav Petkov" <bp@a>
Cc: linux-s390@vger.kernel.org, linux-kernel@vger.kernel.org,
linux-api@vger.kernel.org, x86@kernel.org,
linux-arm-kernel@lists.infradead.org,
kernel-hardening@lists.openwall.com
Subject: [PATCH v5 3/4] arm/syscalls: Specific usage of verify_pre_usermode_state
Date: Thu, 23 Mar 2017 10:25:14 -0700 [thread overview]
Message-ID: <20170323172515.27950-3-thgarnie@google.com> (raw)
In-Reply-To: <20170323172515.27950-1-thgarnie@google.com>
Implement specific usage of verify_pre_usermode_state for user-mode
returns for arm.
---
Based on next-20170322
---
arch/arm/Kconfig | 1 +
arch/arm/kernel/entry-common.S | 16 +++++++++++++++-
2 files changed, 16 insertions(+), 1 deletion(-)
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index fcbc5ef1ec69..10c6dc3dfff9 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -12,6 +12,7 @@ config ARM
select ARCH_HAVE_CUSTOM_GPIO_H
select ARCH_HAS_GCOV_PROFILE_ALL
select ARCH_MIGHT_HAVE_PC_PARPORT
+ select ARCH_NO_SYSCALL_VERIFY_PRE_USERMODE_STATE
select ARCH_OPTIONAL_KERNEL_RWX if ARCH_HAS_STRICT_KERNEL_RWX
select ARCH_OPTIONAL_KERNEL_RWX_DEFAULT if CPU_V7
select ARCH_SUPPORTS_ATOMIC_RMW
diff --git a/arch/arm/kernel/entry-common.S b/arch/arm/kernel/entry-common.S
index eb5cd77bf1d8..88c72c4e44ad 100644
--- a/arch/arm/kernel/entry-common.S
+++ b/arch/arm/kernel/entry-common.S
@@ -12,6 +12,7 @@
#include <asm/unistd.h>
#include <asm/ftrace.h>
#include <asm/unwind.h>
+#include <asm/memory.h>
#ifdef CONFIG_AEABI
#include <asm/unistd-oabi.h>
#endif
@@ -27,7 +28,6 @@
#include "entry-header.S"
-
.align 5
#if !(IS_ENABLED(CONFIG_TRACE_IRQFLAGS) || IS_ENABLED(CONFIG_CONTEXT_TRACKING))
/*
@@ -40,9 +40,12 @@ ret_fast_syscall:
UNWIND(.fnstart )
UNWIND(.cantunwind )
disable_irq_notrace @ disable interrupts
+ ldr r2, [tsk, #TI_ADDR_LIMIT]
ldr r1, [tsk, #TI_FLAGS] @ re-check for syscall tracing
tst r1, #_TIF_SYSCALL_WORK | _TIF_WORK_MASK
bne fast_work_pending
+ cmp r2, #TASK_SIZE
+ blne addr_limit_fail
/* perform architecture specific actions before user return */
arch_ret_to_user r1, lr
@@ -66,6 +69,7 @@ ret_fast_syscall:
UNWIND(.cantunwind )
str r0, [sp, #S_R0 + S_OFF]! @ save returned r0
disable_irq_notrace @ disable interrupts
+ ldr r2, [tsk, #TI_ADDR_LIMIT]
ldr r1, [tsk, #TI_FLAGS] @ re-check for syscall tracing
tst r1, #_TIF_SYSCALL_WORK | _TIF_WORK_MASK
beq no_work_pending
@@ -82,6 +86,7 @@ slow_work_pending:
mov r2, why @ 'syscall'
bl do_work_pending
cmp r0, #0
+ ldreq r2, [tsk, #TI_ADDR_LIMIT]
beq no_work_pending
movlt scno, #(__NR_restart_syscall - __NR_SYSCALL_BASE)
ldmia sp, {r0 - r6} @ have to reload r0 - r6
@@ -99,9 +104,12 @@ ret_slow_syscall:
disable_irq_notrace @ disable interrupts
ENTRY(ret_to_user_from_irq)
ldr r1, [tsk, #TI_FLAGS]
+ ldr r2, [tsk, #TI_ADDR_LIMIT]
tst r1, #_TIF_WORK_MASK
bne slow_work_pending
no_work_pending:
+ cmp r2, #TASK_SIZE
+ blne addr_limit_fail
asm_trace_hardirqs_on save = 0
/* perform architecture specific actions before user return */
@@ -125,6 +133,12 @@ ENTRY(ret_from_fork)
b ret_slow_syscall
ENDPROC(ret_from_fork)
+addr_limit_fail:
+ stmfd sp!, {r0, lr}
+ bl asm_verify_pre_usermode_state
+ ldmfd sp!, {r0, lr}
+ ret lr
+
/*=============================================================================
* SWI handler
*-----------------------------------------------------------------------------
--
2.12.1.500.gab5fba24ee-goog
next prev parent reply other threads:[~2017-03-23 17:25 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-03-23 17:25 [PATCH v5 1/4] syscalls: Restore address limit after a syscall Thomas Garnier
2017-03-23 17:25 ` [PATCH v5 2/4] x86/syscalls: Specific usage of verify_pre_usermode_state Thomas Garnier
2017-03-23 20:36 ` Thomas Garnier
2017-03-23 17:25 ` Thomas Garnier [this message]
[not found] ` <20170323172515.27950-3-thgarnie-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org>
2017-03-23 20:38 ` [PATCH v5 3/4] arm/syscalls: " Thomas Garnier
2017-03-23 17:25 ` [PATCH v5 4/4] arm64/syscalls: " Thomas Garnier
[not found] ` <20170323172515.27950-4-thgarnie-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org>
2017-03-23 20:37 ` Thomas Garnier
[not found] ` <20170323172515.27950-1-thgarnie-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org>
2017-03-23 20:15 ` [PATCH v5 1/4] syscalls: Restore address limit after a syscall Kees Cook
[not found] ` <CAGXu5jKbqOvb2TtfpXhjPQFxEShaBu=RbBQORtqhcF1bD3As6w-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2017-03-31 15:34 ` Thomas Garnier
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