ethtool: Null-terminate filename passed to ethtool_ops::flash_device

The parameters for ETHTOOL_FLASHDEV include a filename, which ought to
be null-terminated.  Currently the only driver that implements
ethtool_ops::flash_device attempts to add a null terminator if
necessary, but does it wrongly.  Do it in the ethtool core instead.

Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 2 insertions, 0 deletions

diff --git a/net/core/ethtool.c b/net/core/ethtool.c
index 369b41894527..3f79db1b612a 100644
--- a/net/core/ethtool.c
+++ b/net/core/ethtool.c
@@ -1190,6 +1190,8 @@ static noinline_for_stack int ethtool_flash_device(struct net_device *dev,
         if (!dev->ethtool_ops->flash_device)
                 return -EOPNOTSUPP;
 
+        efl.data[ETHTOOL_FLASH_MAX_FILENAME - 1] = 0;
+
         return dev->ethtool_ops->flash_device(dev, &efl);
 }