From: Arnd Bergmann arnd@arndb.de

The get_user()/put_user() functions are meant to check for access_ok(), while the __get_user()/__put_user() functions don't.

This broke in 4.19 for nds32, when it gained an extraneous check in __get_user(), but lost the check it needs in __put_user().

Fixes: 487913ab18c2 ("nds32: Extract the checking and getting pointer to a macro") Cc: stable@vger.kernel.org @ v4.19+ Signed-off-by: Arnd Bergmann arnd@arndb.de --- arch/nds32/include/asm/uaccess.h | 22 +++++++++++++++++----- 1 file changed, 17 insertions(+), 5 deletions(-)

diff --git a/arch/nds32/include/asm/uaccess.h b/arch/nds32/include/asm/uaccess.h index d4cbf069dc22..37a40981deb3 100644 --- a/arch/nds32/include/asm/uaccess.h +++ b/arch/nds32/include/asm/uaccess.h @@ -70,9 +70,7 @@ static inline void set_fs(mm_segment_t fs) * versions are void (ie, don't return a value as such). */

-#define get_user __get_user \ - -#define __get_user(x, ptr) \ +#define get_user(x, ptr) \ ({ \ long __gu_err = 0; \ __get_user_check((x), (ptr), __gu_err); \ @@ -85,6 +83,14 @@ static inline void set_fs(mm_segment_t fs) (void)0; \ })

+#define __get_user(x, ptr) \ +({ \ + long __gu_err = 0; \ + const __typeof__(*(ptr)) __user *__p = (ptr); \ + __get_user_err((x), __p, (__gu_err)); \ + __gu_err; \ +}) + #define __get_user_check(x, ptr, err) \ ({ \ const __typeof__(*(ptr)) __user *__p = (ptr); \ @@ -165,12 +171,18 @@ do { \ : "r"(addr), "i"(-EFAULT) \ : "cc")

-#define put_user __put_user \ +#define put_user(x, ptr) \ +({ \ + long __pu_err = 0; \ + __put_user_check((x), (ptr), __pu_err); \ + __pu_err; \ +})

#define __put_user(x, ptr) \ ({ \ long __pu_err = 0; \ - __put_user_err((x), (ptr), __pu_err); \ + __typeof__(*(ptr)) __user *__p = (ptr); \ + __put_user_err((x), __p, __pu_err); \ __pu_err; \ })