[PATCH net-next] ethtool: propagate get_coalesce return value

[Heiner Kallweit]

get_coalesce returns 0 or ERRNO, but the return value isn't checked.
The returned coalesce data may be invalid if an ERRNO is set,
therefore better check and propagate the return value.

Signed-off-by: Heiner Kallweit <hkallwe...@gmail.com>
---
 net/ethtool/ioctl.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/net/ethtool/ioctl.c b/net/ethtool/ioctl.c
index eeb1137a3..923e220ff 100644
--- a/net/ethtool/ioctl.c
+++ b/net/ethtool/ioctl.c
@@ -1510,11 +1510,14 @@ static noinline_for_stack int 
ethtool_get_coalesce(struct net_device *dev,
                                                   void __user *useraddr)
 {
        struct ethtool_coalesce coalesce = { .cmd = ETHTOOL_GCOALESCE };
+       int ret;
 
        if (!dev->ethtool_ops->get_coalesce)
                return -EOPNOTSUPP;
 
-       dev->ethtool_ops->get_coalesce(dev, &coalesce);
+       ret = dev->ethtool_ops->get_coalesce(dev, &coalesce);
+       if (ret)
+               return ret;
 
        if (copy_to_user(useraddr, &coalesce, sizeof(coalesce)))
                return -EFAULT;
-- 
2.26.2