powerpc/uaccess: Enable hardened usercopy
Enables CONFIG_HARDENED_USERCOPY checks on powerpc.
Based on code from PaX and grsecurity.
Signed-off-by: Kees Cook <keescook@chromium.org>
Tested-by: Michael Ellerman <mpe@ellerman.id.au>
diff --git a/arch/powerpc/include/asm/uaccess.h b/arch/powerpc/include/asm/uaccess.h
index b7c20f0..c1dc6c1 100644
--- a/arch/powerpc/include/asm/uaccess.h
+++ b/arch/powerpc/include/asm/uaccess.h
@@ -310,10 +310,15 @@
{
unsigned long over;
- if (access_ok(VERIFY_READ, from, n))
+ if (access_ok(VERIFY_READ, from, n)) {
+ if (!__builtin_constant_p(n))
+ check_object_size(to, n, false);
return __copy_tofrom_user((__force void __user *)to, from, n);
+ }
if ((unsigned long)from < TASK_SIZE) {
over = (unsigned long)from + n - TASK_SIZE;
+ if (!__builtin_constant_p(n - over))
+ check_object_size(to, n - over, false);
return __copy_tofrom_user((__force void __user *)to, from,
n - over) + over;
}
@@ -325,10 +330,15 @@
{
unsigned long over;
- if (access_ok(VERIFY_WRITE, to, n))
+ if (access_ok(VERIFY_WRITE, to, n)) {
+ if (!__builtin_constant_p(n))
+ check_object_size(from, n, true);
return __copy_tofrom_user(to, (__force void __user *)from, n);
+ }
if ((unsigned long)to < TASK_SIZE) {
over = (unsigned long)to + n - TASK_SIZE;
+ if (!__builtin_constant_p(n))
+ check_object_size(from, n - over, true);
return __copy_tofrom_user(to, (__force void __user *)from,
n - over) + over;
}
@@ -372,6 +382,10 @@
if (ret == 0)
return 0;
}
+
+ if (!__builtin_constant_p(n))
+ check_object_size(to, n, false);
+
return __copy_tofrom_user((__force void __user *)to, from, n);
}
@@ -398,6 +412,9 @@
if (ret == 0)
return 0;
}
+ if (!__builtin_constant_p(n))
+ check_object_size(from, n, true);
+
return __copy_tofrom_user(to, (__force const void __user *)from, n);
}