From 28c618abeee3380a4ead50fe9863b692dd851e07 Mon Sep 17 00:00:00 2001
From: Hailong Liu <liu.hailong6@zte.com.cn>
Date: Wed, 13 Feb 2019 16:29:36 +0000
Subject: [PATCH] uio: fix wrong return value from uio_mmap()

commit e7de2590f18a272e63732b9d519250d1b522b2c4 upstream.

uio_mmap has multiple fail paths to set return value to nonzero then
goto out. However, it always returns *0* from the *out* at end, and
this will mislead callers who check the return value of this function.

Fixes: 57c5f4df0a5a0ee ("uio: fix crash after the device is unregistered")
CC: Xiubo Li <xiubli@redhat.com>
Signed-off-by: Hailong Liu <liu.hailong6@zte.com.cn>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Jiang Biao <jiang.biao2@zte.com.cn>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Tommi Rantala <tommi.t.rantala@nokia.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/uio/uio.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/uio/uio.c b/drivers/uio/uio.c
index 262610192755..fed2d8fa4d4d 100644
--- a/drivers/uio/uio.c
+++ b/drivers/uio/uio.c
@@ -816,7 +816,7 @@ static int uio_mmap(struct file *filep, struct vm_area_struct *vma)
 
 out:
 	mutex_unlock(&idev->info_lock);
-	return 0;
+	return ret;
 }
 
 static const struct file_operations uio_fops = {
-- 
2.50.1