MIPS: Enable hardened usercopy

Enable CONFIG_HARDENED_USERCOPY checks for MIPS, calling check_object
size in all of copy_{to,from}_user(), __copy_{to,from}_user() &
__copy_{to,from}_user_inatomic().

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/14371/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

2 files changed, 19 insertions, 0 deletions

diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig
index a7d9224c2a50..7f6da2c8023d 100644
--- a/arch/mips/Kconfig
+++ b/arch/mips/Kconfig
@@ -66,6 +66,7 @@ config MIPS
         select HANDLE_DOMAIN_IRQ
         select HAVE_EXIT_THREAD
         select HAVE_REGS_AND_STACK_ACCESS_API
+        select HAVE_ARCH_HARDENED_USERCOPY
 
 menu "Machine selection"
 
diff --git a/arch/mips/include/asm/uaccess.h b/arch/mips/include/asm/uaccess.h
index 21a2aaba20d5..c65707df61f4 100644
--- a/arch/mips/include/asm/uaccess.h
+++ b/arch/mips/include/asm/uaccess.h
@@ -858,7 +858,10 @@ extern size_t __copy_user(void *__to, const void *__from, size_t __n);
         __cu_to = (to);                                                 \
         __cu_from = (from);                                             \
         __cu_len = (n);                                                 \
+                                                                        \
+        check_object_size(__cu_from, __cu_len, true);                   \
         might_fault();                                                  \
+                                                                        \
         if (eva_kernel_access())                                        \
                 __cu_len = __invoke_copy_to_kernel(__cu_to, __cu_from,  \
                                                    __cu_len);           \
@@ -879,6 +882,9 @@ extern size_t __copy_user_inatomic(void *__to, const void *__from, size_t __n);
         __cu_to = (to);                                                 \
         __cu_from = (from);                                             \
         __cu_len = (n);                                                 \
+                                                                        \
+        check_object_size(__cu_from, __cu_len, true);                   \
+                                                                        \
         if (eva_kernel_access())                                        \
                 __cu_len = __invoke_copy_to_kernel(__cu_to, __cu_from,  \
                                                    __cu_len);           \
@@ -897,6 +903,9 @@ extern size_t __copy_user_inatomic(void *__to, const void *__from, size_t __n);
         __cu_to = (to);                                                 \
         __cu_from = (from);                                             \
         __cu_len = (n);                                                 \
+                                                                        \
+        check_object_size(__cu_to, __cu_len, false);                    \
+                                                                        \
         if (eva_kernel_access())                                        \
                 __cu_len = __invoke_copy_from_kernel_inatomic(__cu_to,  \
                                                               __cu_from,\
@@ -931,6 +940,9 @@ extern size_t __copy_user_inatomic(void *__to, const void *__from, size_t __n);
         __cu_to = (to);                                                 \
         __cu_from = (from);                                             \
         __cu_len = (n);                                                 \
+                                                                        \
+        check_object_size(__cu_from, __cu_len, true);                   \
+                                                                        \
         if (eva_kernel_access()) {                                      \
                 __cu_len = __invoke_copy_to_kernel(__cu_to,             \
                                                    __cu_from,           \
@@ -1123,6 +1135,9 @@ extern size_t __copy_in_user_eva(void *__to, const void *__from, size_t __n);
         __cu_to = (to);                                                 \
         __cu_from = (from);                                             \
         __cu_len = (n);                                                 \
+                                                                        \
+        check_object_size(__cu_to, __cu_len, false);                    \
+                                                                        \
         if (eva_kernel_access()) {                                      \
                 __cu_len = __invoke_copy_from_kernel(__cu_to,           \
                                                      __cu_from,         \
@@ -1161,6 +1176,9 @@ extern size_t __copy_in_user_eva(void *__to, const void *__from, size_t __n);
         __cu_to = (to);                                                 \
         __cu_from = (from);                                             \
         __cu_len = (n);                                                 \
+                                                                        \
+        check_object_size(__cu_to, __cu_len, false);                    \
+                                                                        \
         if (eva_kernel_access()) {                                      \
                 __cu_len = __invoke_copy_from_kernel(__cu_to,           \
                                                      __cu_from,         \