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

[Kees Cook]

Enables CONFIG_HARDENED_USERCOPY checks on sparc.

Based on code from PaX and grsecurity.

Signed-off-by: Kees Cook <keesc...@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

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