From cdf53441368cc02ee4aa8a8343a5dc25132836f0 Mon Sep 17 00:00:00 2001
From: Kay Sievers <kay@vrfy.org>
Date: Mon, 30 Jul 2012 14:40:08 -0700
Subject: [PATCH] kmsg: /dev/kmsg - properly return possible copy_from_user()
 failure

Reported-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Kay Sievers <kay@vrfy.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---
 kernel/printk.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/kernel/printk.c b/kernel/printk.c
index 50c96b5651b..852269adad2 100644
--- a/kernel/printk.c
+++ b/kernel/printk.c
@@ -389,8 +389,10 @@ static ssize_t devkmsg_writev(struct kiocb *iocb, const struct iovec *iv,
 
 	line = buf;
 	for (i = 0; i < count; i++) {
-		if (copy_from_user(line, iv[i].iov_base, iv[i].iov_len))
+		if (copy_from_user(line, iv[i].iov_base, iv[i].iov_len)) {
+			ret = -EFAULT;
 			goto out;
+		}
 		line += iv[i].iov_len;
 	}
 
-- 
2.20.1