base/node.c: initialize the accessor list before registering

[ Upstream commit 48b5928e18dc27e05cab3dc4c78cd8a15baaf1e5 ]

The current code registers the node as available in the node array
before initializing the accessor list.  This makes it so that
anything which might access the accessor list as a result of
allocations will cause an undefined memory access.

In one example, an extension to access hmat data during interleave
caused this undefined access as a result of a bulk allocation
that occurs during node initialization but before the accessor
list is initialized.

Initialize the accessor list before making the node generally
available to the global system.

Fixes: 08d9dbe72b1f ("node: Link memory nodes to their compute nodes")
Signed-off-by: Gregory Price <gregory.price@memverge.com>
Link: https://lore.kernel.org/r/20231030044239.971756-1-gregory.price@memverge.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/base/node.c b/drivers/base/node.c
index 493d533..4d588f4 100644 (file)
--- a/drivers/base/node.c
+++ b/drivers/base/node.c
@@ -868,11 +868,15 @@ int __register_one_node(int nid)
 {
        int error;
        int cpu;
+       struct node *node;
 
-       node_devices[nid] = kzalloc(sizeof(struct node), GFP_KERNEL);
-       if (!node_devices[nid])
+       node = kzalloc(sizeof(struct node), GFP_KERNEL);
+       if (!node)
                return -ENOMEM;
 
+       INIT_LIST_HEAD(&node->access_list);
+       node_devices[nid] = node;
+
        error = register_node(node_devices[nid], nid);
 
        /* link cpu under this node */
@@ -881,7 +885,6 @@ int __register_one_node(int nid)
                        register_cpu_under_node(cpu, nid);
        }
 
-       INIT_LIST_HEAD(&node_devices[nid]->access_list);
        node_init_caches(nid);
 
        return error;