[PATCH v2 08/11] sparc/uaccess: Enable hardened usercopy

Kees Cook
2016-07-13T21:58:24Z

Enables CONFIG_HARDENED_USERCOPY checks on sparc.

Based on code from PaX and grsecurity.

Signed-off-by: Kees Cook <keescook@chromium.org>
---
arch/sparc/Kconfig | 1 +
arch/sparc/include/asm/uaccess_32.h | 14 ++++++++++----
arch/sparc/include/asm/uaccess_64.h | 11 +++++++++--
3 files changed, 20 insertions(+), 6 deletions(-)

diff --git a/arch/sparc/Kconfig b/arch/sparc/Kconfig
index 546293d9e6c5..59b09600dd32 100644
--- a/arch/sparc/Kconfig
+++ b/arch/sparc/Kconfig
@@ -43,6 +43,7 @@ config SPARC
select OLD_SIGSUSPEND
select ARCH_HAS_SG_CHAIN
select CPU_NO_EFFICIENT_FFS
+ select HAVE_ARCH_HARDENED_USERCOPY

config SPARC32
def_bool !64BIT
diff --git a/arch/sparc/include/asm/uaccess_32.h b/arch/sparc/include/asm/uaccess_32.h
index 57aca2792d29..341a5a133f48 100644
--- a/arch/sparc/include/asm/uaccess_32.h
+++ b/arch/sparc/include/asm/uaccess_32.h
@@ -248,22 +248,28 @@ unsigned long __copy_user(void __user *to, const void __user *from, unsigned lon

static inline unsigned long copy_to_user(void __user *to, const void *from, unsigned long n)
{
- if (n && __access_ok((unsigned long) to, n))
+ if (n && __access_ok((unsigned long) to, n)) {
+ if (!__builtin_constant_p(n))
+ check_object_size(from, n, true);
return __copy_user(to, (__force void __user *) from, n);
- else
+ } else
return n;
}

static inline unsigned long __copy_to_user(void __user *to, const void *from, unsigned long n)
{
+ if (!__builtin_constant_p(n))
+ check_object_size(from, n, true);
return __copy_user(to, (__force void __user *) from, n);
}

static inline unsigned long copy_from_user(void *to, const void __user *from, unsigned long n)
{
- if (n && __access_ok((unsigned long) from, n))
+ if (n && __access_ok((unsigned long) from, n)) {
+ if (!__builtin_constant_p(n))
+ check_object_size(to, n, false);
return __copy_user((__force void __user *) to, from, n);
- else
+ } else
return n;
}

diff --git a/arch/sparc/include/asm/uaccess_64.h b/arch/sparc/include/asm/uaccess_64.h
index e9a51d64974d..8bda94fab8e8 100644
--- a/arch/sparc/include/asm/uaccess_64.h
+++ b/arch/sparc/include/asm/uaccess_64.h
@@ -210,8 +210,12 @@ unsigned long copy_from_user_fixup(void *to, const void __user *from,
static inline unsigned long __must_check
copy_from_user(void *to, const void __user *from, unsigned long size)
{
- unsigned long ret = ___copy_from_user(to, from, size);
+ unsigned long ret;

+ if (!__builtin_constant_p(size))
+ check_object_size(to, size, false);
+
+ ret = ___copy_from_user(to, from, size);
if (unlikely(ret))
ret = copy_from_user_fixup(to, from, size);

@@ -227,8 +231,11 @@ unsigned long copy_to_user_fixup(void __user *to, const void *from,
static inline unsigned long __must_check
copy_to_user(void __user *to, const void *from, unsigned long size)
{
- unsigned long ret = ___copy_to_user(to, from, size);
+ unsigned long ret;

+ if (!__builtin_constant_p(size))
+ check_object_size(from, size, true);
+ ret = ___copy_to_user(to, from, size);
if (unlikely(ret))
ret = copy_to_user_fixup(to, from, size);
return ret;
--
2.7.4