From: Al Viro <viro@zeniv.linux.org.uk>
Date: Sat, 20 Aug 2016 23:03:37 +0000 (-0400)
Subject: parisc: fix copy_from_user()
X-Git-Tag: firefly_0821_release~176^2~4^2~28^2~10
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=25581084396957ea7fc0a265c3ab4bacb07b15c1;p=firefly-linux-kernel-4.4.55.git

parisc: fix copy_from_user()

commit aace880feea38875fbc919761b77e5732a3659ef upstream.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/arch/parisc/include/asm/uaccess.h b/arch/parisc/include/asm/uaccess.h
index 1960b87c1c8b..4ad51465890b 100644
--- a/arch/parisc/include/asm/uaccess.h
+++ b/arch/parisc/include/asm/uaccess.h
@@ -10,6 +10,7 @@
 #include <asm-generic/uaccess-unaligned.h>
 
 #include <linux/bug.h>
+#include <linux/string.h>
 
 #define VERIFY_READ 0
 #define VERIFY_WRITE 1
@@ -245,13 +246,14 @@ static inline unsigned long __must_check copy_from_user(void *to,
                                           unsigned long n)
 {
         int sz = __compiletime_object_size(to);
-        int ret = -EFAULT;
+        unsigned long ret = n;
 
         if (likely(sz == -1 || !__builtin_constant_p(n) || sz >= n))
                 ret = __copy_from_user(to, from, n);
         else
                 copy_from_user_overflow();
-
+	if (unlikely(ret))
+		memset(to + (n - ret), 0, ret);
         return ret;
 }