CVE-2026-64123

In the Linux kernel, the following vulnerability has been resolved:

net: hsr: defer node table free until after RCU readers

HSR node-list and node-status generic-netlink operations run under

rcu_read_lock(). They walk hsr->node_db through hsr_get_next_node() and

hsr_get_node_data(), but RTM_DELLINK teardown removes the same node table

with plain list_del() and frees each node immediately.

That lets a generic-netlink reader hold a struct hsr_node pointer across

hsr_dellink(). In a KASAN build, widening the reader window after

hsr_get_next_node() obtains the node reproduces a slab-use-after-free

when the reader copies node->macaddress_A; the freeing stack is

hsr_del_nodes() from hsr_dellink().

Use list_del_rcu() and defer the free through the existing

hsr_free_node_rcu() callback. This matches the lifetime rule used by the

HSR prune paths, which already delete nodes with list_del_rcu() and

call_rcu().