From e33d1f6f72cc82fcfc3d1fb20c9e3ad83b1928fa Mon Sep 17 00:00:00 2001 From: Al Viro Date: Sat, 20 Aug 2016 16:36:36 -0400 Subject: [PATCH] nios2: copy_from_user() should zero the tail of destination Cc: stable@vger.kernel.org Signed-off-by: Al Viro --- arch/nios2/include/asm/uaccess.h | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) diff --git a/arch/nios2/include/asm/uaccess.h b/arch/nios2/include/asm/uaccess.h index caa51ff85a3c..2b4b9e919675 100644 --- a/arch/nios2/include/asm/uaccess.h +++ b/arch/nios2/include/asm/uaccess.h @@ -102,9 +102,12 @@ extern long __copy_to_user(void __user *to, const void *from, unsigned long n); static inline long copy_from_user(void *to, const void __user *from, unsigned long n) { - if (!access_ok(VERIFY_READ, from, n)) - return n; - return __copy_from_user(to, from, n); + unsigned long res = n; + if (access_ok(VERIFY_READ, from, n)) + res = __copy_from_user(to, from, n); + if (unlikely(res)) + memset(to + (n - res), 0, res); + return res; } static inline long copy_to_user(void __user *to, const void *from, -- 2.25.1