asm-generic: make get_user() clear the destination on errors

commit 9ad18b75c2f6e4a78ce204e79f37781f8815c0fa upstream.

both for access_ok() failures and for faults halfway through

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Willy Tarreau <w@1wt.eu>
This commit is contained in:
Al Viro 2016-08-17 23:19:01 -04:00 committed by syphyr
parent 3ccefd6854
commit e8c99a287a
1 changed files with 7 additions and 3 deletions

View File

@ -228,14 +228,18 @@ extern int __put_user_bad(void) __attribute__((noreturn));
might_sleep(); \
access_ok(VERIFY_READ, ptr, sizeof(*ptr)) ? \
__get_user(x, ptr) : \
-EFAULT; \
((x) = (__typeof__(*(ptr)))0,-EFAULT); \
})
#ifndef __get_user_fn
static inline int __get_user_fn(size_t size, const void __user *ptr, void *x)
{
size = __copy_from_user(x, ptr, size);
return size ? -EFAULT : size;
size_t n = __copy_from_user(x, ptr, size);
if (unlikely(n)) {
memset(x + (size - n), 0, n);
return -EFAULT;
}
return 0;
}
#define __get_user_fn(sz, u, k) __get_user_fn(sz, u, k)