[PATCH 3/3] xtensa: add missing __user annotations to asm/uaccess.h

Max Filippov
2020-05-22T21:42:24Z

clear_user, strncpy_user, strnlen_user and their helpers operate on user
pointers, but don't have their arguments marked as __user.
Add __user annotation to userspace pointers of those functions.
Fix open-coded access check in the strnlen_user while at it.

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
---
arch/xtensa/include/asm/uaccess.h | 18 ++++++++----------
1 file changed, 8 insertions(+), 10 deletions(-)

diff --git a/arch/xtensa/include/asm/uaccess.h b/arch/xtensa/include/asm/uaccess.h
index 445bb4cf3c28..e933ded0d07b 100644
--- a/arch/xtensa/include/asm/uaccess.h
+++ b/arch/xtensa/include/asm/uaccess.h
@@ -270,15 +270,15 @@ raw_copy_to_user(void __user *to, const void *from, unsigned long n)
*/

static inline unsigned long
-__xtensa_clear_user(void *addr, unsigned long size)
+__xtensa_clear_user(void __user *addr, unsigned long size)
{
- if (!__memset(addr, 0, size))
+ if (!__memset((void __force *)addr, 0, size))
return size;
return 0;
}

static inline unsigned long
-clear_user(void *addr, unsigned long size)
+clear_user(void __user *addr, unsigned long size)
{
if (access_ok(addr, size))
return __xtensa_clear_user(addr, size);
@@ -290,10 +290,10 @@ clear_user(void *addr, unsigned long size)

#ifndef CONFIG_GENERIC_STRNCPY_FROM_USER

-extern long __strncpy_user(char *, const char *, long);
+extern long __strncpy_user(char *dst, const char __user *src, long count);

static inline long
-strncpy_from_user(char *dst, const char *src, long count)
+strncpy_from_user(char *dst, const char __user *src, long count)
{
if (access_ok(src, 1))
return __strncpy_user(dst, src, count);
@@ -306,13 +306,11 @@ long strncpy_from_user(char *dst, const char *src, long count);
/*
* Return the size of a string (including the ending 0!)
*/
-extern long __strnlen_user(const char *, long);
+extern long __strnlen_user(const char __user *str, long len);

-static inline long strnlen_user(const char *str, long len)
+static inline long strnlen_user(const char __user *str, long len)
{
- unsigned long top = __kernel_ok ? ~0UL : TASK_SIZE - 1;
-
- if ((unsigned long)str > top)
+ if (!access_ok(str, 1))
return 0;
return __strnlen_user(str, len);
}
--
2.20.1