From: Al Viro <viro@ZenIV.linux.org.uk>
Date: Wed, 11 Nov 2015 02:42:49 +0000 (-0700)
Subject: dax_io(): don't let non-error value escape via retval instead of EFAULT
X-Git-Tag: v4.1.12-92~18^2^2~67
X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=5a73a635f5fcf6ed41482ef6471faaf1e84764a7;p=users%2Fjedix%2Flinux-maple.git

dax_io(): don't let non-error value escape via retval instead of EFAULT

Orabug: 22913653

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Reported-by: Sasha Levin <sasha.levin@oracle.com>
Cc: stable@vger.kernel.org # 4.0+
Signed-off-by: Jens Axboe <axboe@fb.com>
(cherry picked from commit cadfbb6ec2e55171479191046142c927a8b12d87)
Signed-off-by: Dan Duval <dan.duval@oracle.com>
---

diff --git a/fs/dax.c b/fs/dax.c
index 131fd35ae39d5..8e17b371aeb89 100644
--- a/fs/dax.c
+++ b/fs/dax.c
@@ -174,8 +174,10 @@ static ssize_t dax_io(struct inode *inode, struct iov_iter *iter,
 		else
 			len = iov_iter_zero(max - pos, iter);
 
-		if (!len)
+		if (!len) {
+			retval = -EFAULT;
 			break;
+		}
 
 		pos += len;
 		addr += len;