From: Dan Carpenter <dan.carpenter@oracle.com>
Date: Fri, 19 Feb 2021 09:54:38 +0000 (+0300)
Subject: cxl/mem: Return -EFAULT if copy_to_user() fails
X-Git-Tag: howlett/maple/20220722_2~3673^2~1
X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=58294927f468a428c7a1ba09cf986fdca14a2747;p=users%2Fjedix%2Flinux-maple.git

cxl/mem: Return -EFAULT if copy_to_user() fails

The copy_to_user() function returns the number of bytes remaining to be
copied, but we want to return -EFAULT if the copy doesn't complete.

Fixes: b754ffbbc0ee ("cxl/mem: Add basic IOCTL interface")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Link: https://lore.kernel.org/r/YC+K3kgzqm20zCWY@mwanda
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
---

diff --git a/drivers/cxl/mem.c b/drivers/cxl/mem.c
index 6d7d3870b5dab..df895bcca63a6 100644
--- a/drivers/cxl/mem.c
+++ b/drivers/cxl/mem.c
@@ -752,7 +752,10 @@ static int cxl_send_cmd(struct cxl_memdev *cxlmd,
 	if (rc)
 		return rc;
 
-	return copy_to_user(s, &send, sizeof(send));
+	if (copy_to_user(s, &send, sizeof(send)))
+		return -EFAULT;
+
+	return 0;
 }
 
 static long __cxl_memdev_ioctl(struct cxl_memdev *cxlmd, unsigned int cmd,