diff options
Diffstat (limited to 'lib/strncpy_from_user.c')
| -rw-r--r-- | lib/strncpy_from_user.c | 18 |
1 files changed, 14 insertions, 4 deletions
diff --git a/lib/strncpy_from_user.c b/lib/strncpy_from_user.c index 122d8d0e253c..5bb752ff7c61 100644 --- a/lib/strncpy_from_user.c +++ b/lib/strncpy_from_user.c @@ -25,7 +25,7 @@ * hit it), 'max' is the address space maximum (and we return * -EFAULT if we hit it). */ -static inline long do_strncpy_from_user(char *dst, const char __user *src, +static __always_inline long do_strncpy_from_user(char *dst, const char __user *src, unsigned long count, unsigned long max) { const struct word_at_a_time constants = WORD_AT_A_TIME_CONSTANTS; @@ -120,7 +120,19 @@ long strncpy_from_user(char *dst, const char __user *src, long count) if (unlikely(count <= 0)) return 0; - max_addr = user_addr_max(); + kasan_check_write(dst, count); + check_object_size(dst, count, false); + + if (can_do_masked_user_access()) { + long retval; + + src = masked_user_read_access_begin(src); + retval = do_strncpy_from_user(dst, src, count, count); + user_read_access_end(); + return retval; + } + + max_addr = TASK_SIZE_MAX; src_addr = (unsigned long)untagged_addr(src); if (likely(src_addr < max_addr)) { unsigned long max = max_addr - src_addr; @@ -133,8 +145,6 @@ long strncpy_from_user(char *dst, const char __user *src, long count) if (max > count) max = count; - kasan_check_write(dst, count); - check_object_size(dst, count, false); if (user_read_access_begin(src, max)) { retval = do_strncpy_from_user(dst, src, count, max); user_read_access_end(); |