Commit 384816051ca9125cd54750e59c780c2a2655fa4f (SUNRPC: fix races on
PipeFS MOUNT notifications) introduces a regression when we call
rpc_setup_pipedir() with RPCSEC_GSS as the auth flavour.
By calling rpcauth_create() while holding the sn->pipefs_sb_lock, we
end up deadlocking in gss_pipes_dentries_create_net().
Fix is to register the client and release the mutex before calling
rpcauth_create().
Reported-by: Weston Andros Adamson <dros@xxxxxxxxxx>
Tested-by: Weston Andros Adamson <dros@xxxxxxxxxx>
Cc: Stanislav Kinsbursky <skinsbursky@xxxxxxxxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx> # : 3848160: SUNRPC: fix races on PipeFS MOUNT
Cc: <stable@xxxxxxxxxxxxxxx> # : e73f4cc: SUNRPC: split client creation
Signed-off-by: Trond Myklebust <Trond.Myklebust@xxxxxxxxxx>
---
net/sunrpc/clnt.c | 16 +++++++++-------
1 file changed, 9 insertions(+), 7 deletions(-)
diff --git a/net/sunrpc/clnt.c b/net/sunrpc/clnt.c
index f0339ae9..aa40156 100644
--- a/net/sunrpc/clnt.c
+++ b/net/sunrpc/clnt.c
@@ -290,7 +290,7 @@ static int rpc_client_register(const struct rpc_create_args *args,
struct rpc_auth *auth;
struct net *net = rpc_net_ns(clnt);
struct super_block *pipefs_sb;
- int err = 0;
+ int err;
pipefs_sb = rpc_get_sb_net(net);
if (pipefs_sb) {
@@ -299,6 +299,10 @@ static int rpc_client_register(const struct rpc_create_args *args,
goto out;
}
+ rpc_register_client(clnt);
+ if (pipefs_sb)
+ rpc_put_sb_net(net);
+
auth = rpcauth_create(args->authflavor, clnt);
if (IS_ERR(auth)) {
dprintk("RPC: Couldn't create auth handle (flavor %u)\n",
@@ -306,16 +310,14 @@ static int rpc_client_register(const struct rpc_create_args *args,
err = PTR_ERR(auth);
goto err_auth;
}
-
- rpc_register_client(clnt);
+ return 0;
+err_auth:
+ pipefs_sb = rpc_get_sb_net(net);
+ __rpc_clnt_remove_pipedir(clnt);
out:
if (pipefs_sb)
rpc_put_sb_net(net);
return err;
-
-err_auth:
- __rpc_clnt_remove_pipedir(clnt);
- goto out;
}
static struct rpc_clnt * rpc_new_client(const struct rpc_create_args *args, struct rpc_xprt *xprt)
--
1.8.3.1
--
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