SUNRPC: Fix suspicious RCU usage
We need to hold the rcu_read_lock() when calling rcu_dereference(),
otherwise we can't guarantee that the object being dereferenced still
exists.
Fixes: 39e5d2df ("SUNRPC search xprt switch for sockaddr")
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
diff --git a/net/sunrpc/clnt.c b/net/sunrpc/clnt.c
index 34dd7b2..62a4827 100644
--- a/net/sunrpc/clnt.c
+++ b/net/sunrpc/clnt.c
@@ -2753,14 +2753,18 @@
void rpc_clnt_xprt_switch_put(struct rpc_clnt *clnt)
{
+ rcu_read_lock();
xprt_switch_put(rcu_dereference(clnt->cl_xpi.xpi_xpswitch));
+ rcu_read_unlock();
}
EXPORT_SYMBOL_GPL(rpc_clnt_xprt_switch_put);
void rpc_clnt_xprt_switch_add_xprt(struct rpc_clnt *clnt, struct rpc_xprt *xprt)
{
+ rcu_read_lock();
rpc_xprt_switch_add_xprt(rcu_dereference(clnt->cl_xpi.xpi_xpswitch),
xprt);
+ rcu_read_unlock();
}
EXPORT_SYMBOL_GPL(rpc_clnt_xprt_switch_add_xprt);
@@ -2770,9 +2774,8 @@
struct rpc_xprt_switch *xps;
bool ret;
- xps = rcu_dereference(clnt->cl_xpi.xpi_xpswitch);
-
rcu_read_lock();
+ xps = rcu_dereference(clnt->cl_xpi.xpi_xpswitch);
ret = rpc_xprt_switch_has_addr(xps, sap);
rcu_read_unlock();
return ret;
