SUNRPC: Fix the minimal size for reply buffer allocation

We must at minimum allocate enough memory to be able to see any auth
errors in the reply from the server.

Fixes: 2c94b8eca1a26 ("SUNRPC: Use au_rslack when computing reply...")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

diff --git a/net/sunrpc/clnt.c b/net/sunrpc/clnt.c
index 4216fe33204a8e3f2634cae5ed2329335b1885da..310873895578230dd6f4a9ef892b297b9e00494f 100644 (file)
--- a/net/sunrpc/clnt.c
+++ b/net/sunrpc/clnt.c
@@ -1730,7 +1730,12 @@ call_allocate(struct rpc_task *task)
        req->rq_callsize = RPC_CALLHDRSIZE + (auth->au_cslack << 1) +
                           proc->p_arglen;
        req->rq_callsize <<= 2;
-       req->rq_rcvsize = RPC_REPHDRSIZE + auth->au_rslack + proc->p_replen;
+       /*
+        * Note: the reply buffer must at minimum allocate enough space
+        * for the 'struct accepted_reply' from RFC5531.
+        */
+       req->rq_rcvsize = RPC_REPHDRSIZE + auth->au_rslack + \
+                       max_t(size_t, proc->p_replen, 2);
        req->rq_rcvsize <<= 2;
 
        status = xprt->ops->buf_alloc(task);