The copy_from_user() function returns the number of bytes remaining which we weren't able to copy. This should return -EFAULT to the user. Fixes: 86609baa4217 ("soc: aspeed: xdma: Add user interface") Signed-off-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx> --- drivers/soc/aspeed/aspeed-xdma.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) diff --git a/drivers/soc/aspeed/aspeed-xdma.c b/drivers/soc/aspeed/aspeed-xdma.c index 91b51a3de8df..e6b4744bda64 100644 --- a/drivers/soc/aspeed/aspeed-xdma.c +++ b/drivers/soc/aspeed/aspeed-xdma.c @@ -569,9 +569,8 @@ static ssize_t aspeed_xdma_write(struct file *file, const char __user *buf, if (len != sizeof(op)) return -EINVAL; - rc = copy_from_user(&op, buf, len); - if (rc) - return rc; + if (copy_from_user(&op, buf, len)) + return -EFAULT; if (!op.len || op.len > client->size || op.direction > ASPEED_XDMA_DIRECTION_UPSTREAM) -- 2.28.0