Re: [PATCH net] net: hsr: free learned nodes on device setup failure

[Hangbin Liu]

On Sat, Aug 08, 2026 at 01:08:14PM +0200, Xin Xie wrote:
> hsr_dev_finalize() can fail after a lower-device RX handler has
> already been registered (slave A is added before the failable slave B
> and interlink adds). RX handlers run in softirq regardless of the
> master's state, so frames received in that window can learn dynamic
> nodes into node_db, and the error unwind never releases them.
> 
> Free both owned dynamic databases in the unwind, mirroring
> hsr_dellink(). proxy_node_db is provably empty on every current error
> exit (only interlink RX feeds it, and the interlink add is the last
> failable step) and is freed for symmetry. The order is safe:
> hsr_del_port() unregisters each RX handler with synchronize_net()
> before hsr_del_nodes() runs, which removes remaining entries with
> list_del_rcu() and defers their release with call_rcu() for readers
> already under RCU.
> 
> Fixes: 81ba6afd6e64 ("net/hsr: Switch from dev_add_pack() to netdev_rx_handler_register()")

Should we use this fix tag? The proxy_node_db is added in
5055cccfc2d1 ("net: hsr: Provide RedBox support (HSR-SAN)").

Thanks
Hangbin