net: dsa: sja1105: flower: reject cross-chip redirect

In the Linux kernel, the following vulnerability has been resolved: net: dsa: sja1105: flower: reject cross-chip redirect dsa_port_from_netdev() may return a valid port from a different switch chip. Programming another chip's port index into the local hardware causes redirection to the wrong port, or an out-of-bounds access if the index exceeds the local chip's port count. Apply a minimal fix that adds a check to catch this case and adjusts the extack message. When cls->common.skip_sw is not set, the operation could instead redirect to the upstream port and let the software or upstream switch(es) handle the forward, but that is not addressed here.

Where it's fixed