@@ -35,6 +35,7 @@ config ARM
select HARDIRQS_SW_RESEND
select HAVE_ARCH_AUDITSYSCALL if (AEABI && !OABI_COMPAT)
select HAVE_ARCH_BITREVERSE if (CPU_32v7M || CPU_32v7) && !CPU_32v6
+ select HAVE_ARCH_HARDENED_USERCOPY
select HAVE_ARCH_JUMP_LABEL if !XIP_KERNEL && !CPU_ENDIAN_BE32 && MMU
select HAVE_ARCH_KGDB if !CPU_ENDIAN_BE32 && MMU
select HAVE_ARCH_MMAP_RND_BITS if MMU
@@ -496,7 +496,10 @@ arm_copy_from_user(void *to, const void __user *from, unsigned long n);
static inline unsigned long __must_check
__copy_from_user(void *to, const void __user *from, unsigned long n)
{
- unsigned int __ua_flags = uaccess_save_and_enable();
+ unsigned int __ua_flags;
+
+ check_object_size(to, n, false);
+ __ua_flags = uaccess_save_and_enable();
n = arm_copy_from_user(to, from, n);
uaccess_restore(__ua_flags);
return n;
@@ -511,11 +514,15 @@ static inline unsigned long __must_check
__copy_to_user(void __user *to, const void *from, unsigned long n)
{
#ifndef CONFIG_UACCESS_WITH_MEMCPY
- unsigned int __ua_flags = uaccess_save_and_enable();
+ unsigned int __ua_flags;
+
+ check_object_size(from, n, true);
+ __ua_flags = uaccess_save_and_enable();
n = arm_copy_to_user(to, from, n);
uaccess_restore(__ua_flags);
return n;
#else
+ check_object_size(from, n, true);
return arm_copy_to_user(to, from, n);
#endif
}
Enables CONFIG_HARDENED_USERCOPY checks on arm. Based on code from PaX and grsecurity. Signed-off-by: Kees Cook <keescook@chromium.org> --- arch/arm/Kconfig | 1 + arch/arm/include/asm/uaccess.h | 11 +++++++++-- 2 files changed, 10 insertions(+), 2 deletions(-)