net: qrtr: ns: Change nodes radix tree to xarray

There is a use after free scenario while iterating through the nodes
radix tree despite the ns being a single threaded process. This can
happen when the radix tree APIs are not synchronized with the
rcu_read_lock() APIs.

Convert the radix tree for nodes to xarray to take advantage of the
built in rcu lock usage provided by xarray.

Signed-off-by: Chris Lew <quic_clew@quicinc.com>
Signed-off-by: Vignesh Viswanathan <quic_viswanat@quicinc.com>
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/qrtr/ns.c b/net/qrtr/ns.c
index af28d9e..b1db0b5 100644 (file)
--- a/net/qrtr/ns.c
+++ b/net/qrtr/ns.c
@@ -16,7 +16,7 @@
 #define CREATE_TRACE_POINTS
 #include <trace/events/qrtr.h>
 
-static RADIX_TREE(nodes, GFP_KERNEL);
+static DEFINE_XARRAY(nodes);
 
 static struct {
        struct socket *sock;
@@ -73,7 +73,7 @@ static struct qrtr_node *node_get(unsigned int node_id)
 {
        struct qrtr_node *node;
 
-       node = radix_tree_lookup(&nodes, node_id);
+       node = xa_load(&nodes, node_id);
        if (node)
                return node;
 
@@ -85,7 +85,7 @@ static struct qrtr_node *node_get(unsigned int node_id)
        node->id = node_id;
        xa_init(&node->servers);
 
-       if (radix_tree_insert(&nodes, node_id, node)) {
+       if (xa_store(&nodes, node_id, node, GFP_KERNEL)) {
                kfree(node);
                return NULL;
        }