SUNRPC: Fix use of static variable in rpcb_getport_async

[ upstream commit ec0dd267bf7d08cb30e321e45a75fd40edd7e528 ]

Because struct rpcbind_args *map was declared static, if two
threads entered this method at the same time, the values
assigned to map could be sent two two differen tasks.
This could cause all sorts of problems, include use-after-free
and double-free of memory.

Fix this by removing the static declaration so that the map
pointer is on the stack.

Signed-off-by: Ben Greear <greearb@candelatech.com>
Cc: stable@kernel.org
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Signed-off-by: Andi Kleen <ak@linux.intel.com>

diff --git a/net/sunrpc/rpcb_clnt.c b/net/sunrpc/rpcb_clnt.c
index dac219a56ae1a7dcf8df9ddff9a128b6caa89dac..4db171f672eea42b12bf58d66f5d83463e1fc2bb 100644 (file)
--- a/net/sunrpc/rpcb_clnt.c
+++ b/net/sunrpc/rpcb_clnt.c
@@ -580,7 +580,7 @@ void rpcb_getport_async(struct rpc_task *task)
        u32 bind_version;
        struct rpc_xprt *xprt;
        struct rpc_clnt *rpcb_clnt;
-       static struct rpcbind_args *map;
+       struct rpcbind_args *map;
        struct rpc_task *child;
        struct sockaddr_storage addr;
        struct sockaddr *sap = (struct sockaddr *)&addr;