[PATCH -next v3] staging: greybus: camera: Switch to memdup_user_nul()

[Yang Yingliang]

Use memdup_user_nul() helper instead of open-coding to
simplify the code.

Reported-by: Hulk Robot <hulkci@xxxxxxxxxx>
Signed-off-by: Yang Yingliang <yangyingliang@xxxxxxxxxx>
---
v3:
  remove duplicate ';'
v2:
  delete unnecessary blank line
  use return PTR_ERR(kbuf) instead
---
 drivers/staging/greybus/camera.c | 13 +++----------
 1 file changed, 3 insertions(+), 10 deletions(-)

diff --git a/drivers/staging/greybus/camera.c b/drivers/staging/greybus/camera.c
index b570e13394ac..2ecdc1bc5092 100644
--- a/drivers/staging/greybus/camera.c
+++ b/drivers/staging/greybus/camera.c
@@ -1120,16 +1120,9 @@ static ssize_t gb_camera_debugfs_write(struct file *file,
 	if (len > 1024)
 		return -EINVAL;
 
-	kbuf = kmalloc(len + 1, GFP_KERNEL);
-	if (!kbuf)
-		return -ENOMEM;
-
-	if (copy_from_user(kbuf, buf, len)) {
-		ret = -EFAULT;
-		goto done;
-	}
-
-	kbuf[len] = '\0';
+	kbuf = memdup_user_nul(buf, len);
+	if (IS_ERR(kbuf))
+		return PTR_ERR(kbuf);
 
 	ret = op->execute(gcam, kbuf, len);
 
-- 
2.25.1