sh: fix copy_from_user()

[ Upstream commit 6e050503a150b2126620c1a1e9b3a368fcd51eac ]

Cc: stable@vger.kernel.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>

diff --git a/arch/sh/include/asm/uaccess.h b/arch/sh/include/asm/uaccess.h
index a49635c512665ddc6b9e70e5d944c57e26d349d6..92ade79ac4272ea22657b3aac6adfb90b1d4105f 100644 (file)
--- a/arch/sh/include/asm/uaccess.h
+++ b/arch/sh/include/asm/uaccess.h
@@ -151,7 +151,10 @@ copy_from_user(void *to, const void __user *from, unsigned long n)
        __kernel_size_t __copy_size = (__kernel_size_t) n;
 
        if (__copy_size && __access_ok(__copy_from, __copy_size))
-               return __copy_user(to, from, __copy_size);
+               __copy_size = __copy_user(to, from, __copy_size);
+
+       if (unlikely(__copy_size))
+               memset(to + (n - __copy_size), 0, __copy_size);
 
        return __copy_size;
 }