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>,
"Al Viro" <viro@zeniv.linux.org.uk>,
"Dave Hansen" <dave.hansen@intel.com>,
"Thomas Garnier" <thgarnie@google.com>,
"René Nyffenegger" <mail@renenyffenegger.ch>,
"Andrew Morton" <akpm@linux-foundation.org>,
"Kees Cook" <keescook@chromium.org>,
"Paul E . McKenney" <paulmck@linux.vnet.ibm.com>,
"Andy Lutomirski" <luto@kernel.org>,
"Ard Biesheuvel" <ard.biesheuvel@linaro.org>,
"Nicolas Pitre" <nicolas.pitre@linaro.org>,
"Petr Mladek" <pmladek@suse.com>,
"Sebastian Andrzej Siewior" <bigeasy@linutronix.de>,
"Sergey Senozhatsky" <sergey.senozhatsky@gmail.com>,
"Helge Deller" <deller@gmx.de>, "Rik van Riel" <riel@redhat.com>,
"Ingo Molnar" <mingo@kernel.org>,
"John Stultz" <john.stultz@linaro.org>,
"Thomas Gleixner" <tglx@linutron>
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 v3 4/4] arm64/syscalls: Specific usage of verify_pre_usermode_state
Date: Fri, 10 Mar 2017 16:05:01 -0800 [thread overview]
Message-ID: <20170311000501.46607-4-thgarnie@google.com> (raw)
In-Reply-To: <20170311000501.46607-1-thgarnie@google.com>
Implement specific usage of verify_pre_usermode_state for user-mode
returns for arm64.
---
Based on next-20170308
---
arch/arm64/Kconfig | 1 +
arch/arm64/kernel/entry.S | 25 +++++++++++++++++++++++++
2 files changed, 26 insertions(+)
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index 896eba61e5ed..da54774838d8 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -24,6 +24,7 @@ config ARM64
select ARCH_WANT_COMPAT_IPC_PARSE_VERSION
select ARCH_WANT_FRAME_POINTERS
select ARCH_HAS_UBSAN_SANITIZE_ALL
+ select ARCH_NO_SYSCALL_VERIFY_PRE_USERMODE_STATE
select ARM_AMBA
select ARM_ARCH_TIMER
select ARM_GIC
diff --git a/arch/arm64/kernel/entry.S b/arch/arm64/kernel/entry.S
index 43512d4d7df2..685b43771ac9 100644
--- a/arch/arm64/kernel/entry.S
+++ b/arch/arm64/kernel/entry.S
@@ -744,6 +744,10 @@ ENDPROC(cpu_switch_to)
ret_fast_syscall:
disable_irq // disable interrupts
str x0, [sp, #S_X0] // returned x0
+ ldr x2, [tsk, #TSK_TI_ADDR_LIMIT] // check addr limit change
+ mov x1, #TASK_SIZE_64
+ cmp x2, x1
+ b.ne addr_limit_fail
ldr x1, [tsk, #TSK_TI_FLAGS] // re-check for syscall tracing
and x2, x1, #_TIF_SYSCALL_WORK
cbnz x2, ret_fast_syscall_trace
@@ -771,6 +775,11 @@ work_pending:
*/
ret_to_user:
disable_irq // disable interrupts
+ ldr x2, [tsk, #TSK_TI_ADDR_LIMIT] // check addr limit change
+ mov x1, #TASK_SIZE_64
+ cmp x2, x1
+ b.ne addr_limit_fail
+
ldr x1, [tsk, #TSK_TI_FLAGS]
and x2, x1, #_TIF_WORK_MASK
cbnz x2, work_pending
@@ -779,6 +788,22 @@ finish_ret_to_user:
kernel_exit 0
ENDPROC(ret_to_user)
+addr_limit_fail:
+#ifdef CONFIG_BUG_ON_DATA_CORRUPTION
+ stp x0, lr, [sp,#-16]!
+ bl verify_pre_usermode_state
+ ldp x0, lr, [sp],#16
+#else
+ /*
+ * Similar to set_fs(USER_DS) in verify_pre_usermode_state without a
+ * warning.
+ */
+ mov x2, #TASK_SIZE_64
+ str x2, [tsk, #TSK_TI_ADDR_LIMIT]
+ ALTERNATIVE(nop, SET_PSTATE_UAO(0), ARM64_HAS_UAO, CONFIG_ARM64_UAO)
+#endif
+ ret lr
+
/*
* This is how we return from a fork.
*/
--
2.12.0.246.ga2ecc84866-goog
prev parent reply other threads:[~2017-03-11 0:05 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-03-11 0:04 [PATCH v3 1/4] syscalls: Restore address limit after a syscall Thomas Garnier
2017-03-11 0:04 ` [PATCH v3 2/4] x86/syscalls: Specific usage of verify_pre_usermode_state Thomas Garnier
2017-03-11 9:42 ` Ingo Molnar
2017-03-13 15:53 ` Thomas Garnier
[not found] ` <20170311094200.GA27700-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
2017-03-13 21:48 ` H. Peter Anvin
2017-03-14 0:04 ` H. Peter Anvin
2017-03-14 9:40 ` H. Peter Anvin
2017-03-14 15:17 ` Thomas Garnier
2017-03-14 15:39 ` Andy Lutomirski
2017-03-14 16:29 ` Thomas Garnier
2017-03-14 16:44 ` H. Peter Anvin
2017-03-14 16:51 ` Thomas Garnier
2017-03-14 17:53 ` H. Peter Anvin
2017-03-15 17:43 ` Thomas Garnier
2017-03-22 19:15 ` Thomas Garnier
2017-03-22 20:21 ` H. Peter Anvin
2017-03-22 20:41 ` Thomas Garnier
2017-03-22 20:49 ` H. Peter Anvin
2017-03-22 21:11 ` Thomas Garnier
[not found] ` <CAJcbSZEouZ2v+q_i-3Xiba2FNT18ipKwF09838vvfSCwEi7e4Q-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2017-03-23 19:14 ` H. Peter Anvin
2017-03-14 16:30 ` H. Peter Anvin
2017-03-11 0:05 ` [PATCH v3 3/4] arm/syscalls: " Thomas Garnier
2017-03-11 0:05 ` Thomas Garnier [this message]
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