sunrpc: fix potential race between setting use_gss_proxy and the upcall rpc_clnt

An nfsd thread can call use_gss_proxy and find it set to '1' but find
gssp_clnt still NULL, so that when it attempts the upcall the result
will be an unnecessary -EIO.

So, ensure that gssp_clnt is created first, and set the use_gss_proxy
variable only if that succeeds.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

diff --git a/net/sunrpc/auth_gss/svcauth_gss.c b/net/sunrpc/auth_gss/svcauth_gss.c
index 1b94a9c..60dc370 100644 (file)
--- a/net/sunrpc/auth_gss/svcauth_gss.c
+++ b/net/sunrpc/auth_gss/svcauth_gss.c
@@ -1317,10 +1317,10 @@ static ssize_t write_gssp(struct file *file, const char __user *buf,
                return res;
        if (i != 1)
                return -EINVAL;
-       res = set_gss_proxy(net, 1);
+       res = set_gssp_clnt(net);
        if (res)
                return res;
-       res = set_gssp_clnt(net);
+       res = set_gss_proxy(net, 1);
        if (res)
                return res;
        return count;