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Michael BommaritoandGreg Kroah-Hartman
c5580114e0
[ Upstream commitaaec7096f9] 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(). Fixes:b9a1e62740("hsr: implement dellink to clean up resources") Cc: stable@vger.kernel.org # v5.3+ Signed-off-by: Michael Bommarito <michael.bommarito@gmail.com> Link: https://patch.msgid.link/20260513233838.3064715-2-michael.bommarito@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> [ replaced `list_del`+`call_rcu(hsr_free_node_rcu)` with `list_del_rcu`+`kfree_rcu(node, rcu_head)` ] Signed-off-by: Sasha Levin <sashal@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>