Received-SPF: pass (google.com: domain of linux-nfs-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
From:   Thiago Rafael Becker <trbecker@gmail.com>
To:     linux-nfs@vger.kernel.org
Cc:     Thiago Rafael Becker <tbecker@redhat.com>,
        Trond Myklebust <trond.myklebust@hammerspace.com>,
        Anna Schumaker <anna.schumaker@netapp.com>,
        "J . Bruce Fields" <bfields@fieldses.org>,
        Chuck Lever <chuck.lever@oracle.com>,
        "David S . Miller" <davem@davemloft.net>,
        Jakub Kicinski <kuba@kernel.org>, netdev@vger.kernel.org,
        linux-kernel@vger.kernel.org,
        Thiago Rafael Becker <trbecker@gmail.com>
Subject: [PATCH] sunrpc: bug on rpc_task_set_client when no client is present.
Date:   Mon, 18 Oct 2021 09:38:12 -0300
Message-Id: <20211018123812.71482-1-trbecker@gmail.com>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

If we pass a NULL client to rpc_task_set_client and no client is
attached to the task, then the kernel will crash later. Antecipate the
crash by checking if a client is available for the task.

Signed-off-by: Thiago Rafael Becker <trbecker@gmail.com>
---
 net/sunrpc/clnt.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/sunrpc/clnt.c b/net/sunrpc/clnt.c
index f056ff931444..ccbc9a9715da 100644
--- a/net/sunrpc/clnt.c
+++ b/net/sunrpc/clnt.c
@@ -1076,7 +1076,7 @@ void rpc_task_set_transport(struct rpc_task *task, struct rpc_clnt *clnt)
 static
 void rpc_task_set_client(struct rpc_task *task, struct rpc_clnt *clnt)
 {
-
+	BUG_ON(clnt == NULL && task->tk_client == NULL);
 	if (clnt != NULL) {
 		rpc_task_set_transport(task, clnt);
 		task->tk_client = clnt;
-- 
2.31.1