From 1d3c1324746fed0e34a5b94d3ed303e7521ed603 Mon Sep 17 00:00:00 2001 From: Kees Cook Date: Thu, 23 Jun 2016 15:10:01 -0700 Subject: [PATCH] powerpc/uaccess: Enable hardened usercopy Enables CONFIG_HARDENED_USERCOPY checks on powerpc. Based on code from PaX and grsecurity. Signed-off-by: Kees Cook Tested-by: Michael Ellerman --- arch/powerpc/Kconfig | 1 + arch/powerpc/include/asm/uaccess.h | 21 +++++++++++++++++++-- 2 files changed, 20 insertions(+), 2 deletions(-) diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig index 0a9d439bcda6..0ac48a81632d 100644 --- a/arch/powerpc/Kconfig +++ b/arch/powerpc/Kconfig @@ -164,6 +164,7 @@ config PPC select ARCH_HAS_UBSAN_SANITIZE_ALL select ARCH_SUPPORTS_DEFERRED_STRUCT_PAGE_INIT select HAVE_LIVEPATCH if HAVE_DYNAMIC_FTRACE_WITH_REGS + select HAVE_ARCH_HARDENED_USERCOPY config GENERIC_CSUM def_bool CPU_LITTLE_ENDIAN diff --git a/arch/powerpc/include/asm/uaccess.h b/arch/powerpc/include/asm/uaccess.h index b7c20f0b8fbe..c1dc6c14deb8 100644 --- a/arch/powerpc/include/asm/uaccess.h +++ b/arch/powerpc/include/asm/uaccess.h @@ -310,10 +310,15 @@ static inline unsigned long copy_from_user(void *to, { 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 @@ static inline unsigned long copy_to_user(void __user *to, { 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 @@ static inline unsigned long __copy_from_user_inatomic(void *to, 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 @@ static inline unsigned long __copy_to_user_inatomic(void __user *to, 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); } -- 2.20.1