s390/uaccess: Enable hardened usercopy

Enables CONFIG_HARDENED_USERCOPY checks on s390.

Signed-off-by: Kees Cook <keescook@chromium.org>

diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig
index a8c259059adf0e7b6af3587d59d2d370e0b0cd5d..9f694311c9ede7591ec0bbda944bc685590ca1de 100644 (file)
--- a/arch/s390/Kconfig
+++ b/arch/s390/Kconfig
@@ -122,6 +122,7 @@ config S390
        select HAVE_ALIGNED_STRUCT_PAGE if SLUB
        select HAVE_ARCH_AUDITSYSCALL
        select HAVE_ARCH_EARLY_PFN_TO_NID
+       select HAVE_ARCH_HARDENED_USERCOPY
        select HAVE_ARCH_JUMP_LABEL
        select CPU_NO_EFFICIENT_FFS if !HAVE_MARCH_Z9_109_FEATURES
        select HAVE_ARCH_SECCOMP_FILTER

diff --git a/arch/s390/lib/uaccess.c b/arch/s390/lib/uaccess.c
index ae4de559e3a04288c6be111de684b3355f35109b..6986c20166f028bd859fa38af033d076a93eb3f3 100644 (file)
--- a/arch/s390/lib/uaccess.c
+++ b/arch/s390/lib/uaccess.c
@@ -104,6 +104,7 @@ static inline unsigned long copy_from_user_mvcp(void *x, const void __user *ptr,
 
 unsigned long __copy_from_user(void *to, const void __user *from, unsigned long n)
 {
+       check_object_size(to, n, false);
        if (static_branch_likely(&have_mvcos))
                return copy_from_user_mvcos(to, from, n);
        return copy_from_user_mvcp(to, from, n);
@@ -177,6 +178,7 @@ static inline unsigned long copy_to_user_mvcs(void __user *ptr, const void *x,
 
 unsigned long __copy_to_user(void __user *to, const void *from, unsigned long n)
 {
+       check_object_size(from, n, true);
        if (static_branch_likely(&have_mvcos))
                return copy_to_user_mvcos(to, from, n);
        return copy_to_user_mvcs(to, from, n);