In the Linux kernel, the following vulnerability has been resolved: net: dsa: sja1105: flower: reject cross-chip redirect dsa_port_from_ne

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.