diff options
Diffstat (limited to 'arch/s390/include')
| -rw-r--r-- | arch/s390/include/asm/uaccess.h | 12 |
1 files changed, 12 insertions, 0 deletions
diff --git a/arch/s390/include/asm/uaccess.h b/arch/s390/include/asm/uaccess.h index cbf0a8745bf..d6b1ed0ec52 100644 --- a/arch/s390/include/asm/uaccess.h +++ b/arch/s390/include/asm/uaccess.h @@ -265,6 +265,12 @@ __copy_from_user(void *to, const void __user *from, unsigned long n) return uaccess.copy_from_user(n, from, to); } +extern void copy_from_user_overflow(void) +#ifdef CONFIG_DEBUG_STRICT_USER_COPY_CHECKS +__compiletime_warning("copy_from_user() buffer size is not provably correct") +#endif +; + /** * copy_from_user: - Copy a block of data from user space. * @to: Destination address, in kernel space. @@ -284,7 +290,13 @@ __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 sz = __compiletime_object_size(to); + might_fault(); + if (unlikely(sz != -1 && sz < n)) { + copy_from_user_overflow(); + return n; + } if (access_ok(VERIFY_READ, from, n)) n = __copy_from_user(to, from, n); else |