On Monday, 12 February 2024 11:41:38 CET Eric Dumazet wrote:
This patch [1] looks suspicious
Shouldn't be caused by this - but this might be another way to trigger the problem. The problem would be visible even without it when a mtu is explicitly set. But the reproducer is not available so I can't actually check what is going on.
I think batman-adv should reject too small MTU values.
You are refering to the size calculated by batadv_tt_local_table_transmit_size(), right? And yes, I would agree that it looks suspicious and might not have been correctly integrated in batadv_max_header_len() when commit a19d3d85e1b8 ("batman-adv: limit local translation table max size") introduced the code. But I think we also need to remove interfaces again when receiving NETDEV_CHANGEMTU and an interface is not having the correctly sized anymore. So have to check how to do this the best way.
Kind regards, Sven