diff options
Diffstat (limited to 'lib/strncpy_from_user.c')
| -rw-r--r-- | lib/strncpy_from_user.c | 23 |
1 files changed, 12 insertions, 11 deletions
diff --git a/lib/strncpy_from_user.c b/lib/strncpy_from_user.c index e304b54c9c7d..fc5b1e2d997d 100644 --- a/lib/strncpy_from_user.c +++ b/lib/strncpy_from_user.c @@ -29,13 +29,6 @@ static inline long do_strncpy_from_user(char *dst, const char __user *src, const struct word_at_a_time constants = WORD_AT_A_TIME_CONSTANTS; unsigned long res = 0; - /* - * Truncate 'max' to the user-specified limit, so that - * we only have one limit we need to check in the loop - */ - if (max > count) - max = count; - if (IS_UNALIGNED(src, dst)) goto byte_at_a_time; @@ -113,12 +106,20 @@ long strncpy_from_user(char *dst, const char __user *src, long count) unsigned long max = max_addr - src_addr; long retval; + /* + * Truncate 'max' to the user-specified limit, so that + * we only have one limit we need to check in the loop + */ + if (max > count) + max = count; + kasan_check_write(dst, count); check_object_size(dst, count, false); - user_access_begin(); - retval = do_strncpy_from_user(dst, src, count, max); - user_access_end(); - return retval; + if (user_access_begin(VERIFY_READ, src, max)) { + retval = do_strncpy_from_user(dst, src, count, max); + user_access_end(); + return retval; + } } return -EFAULT; } |