SUNRPC: Dequeue the request from the receive queue while we're re-encoding
Ensure that we dequeue the request from the transport receive queue
while we're re-encoding to prevent issues like use-after-free when
we release the bvec.
Fixes: 7536908982047 ("SUNRPC: Ensure the bvecs are reset when we re-encode...")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Cc: stable@vger.kernel.org # v4.20+
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
diff --git a/include/linux/sunrpc/xprt.h b/include/linux/sunrpc/xprt.h
index 13e108b..d783e15 100644
--- a/include/linux/sunrpc/xprt.h
+++ b/include/linux/sunrpc/xprt.h
@@ -352,6 +352,7 @@ bool xprt_prepare_transmit(struct rpc_task *task);
void xprt_request_enqueue_transmit(struct rpc_task *task);
void xprt_request_enqueue_receive(struct rpc_task *task);
void xprt_request_wait_receive(struct rpc_task *task);
+void xprt_request_dequeue_xprt(struct rpc_task *task);
bool xprt_request_need_retransmit(struct rpc_task *task);
void xprt_transmit(struct rpc_task *task);
void xprt_end_transmit(struct rpc_task *task);
diff --git a/net/sunrpc/clnt.c b/net/sunrpc/clnt.c
index d8679b60..0359466 100644
--- a/net/sunrpc/clnt.c
+++ b/net/sunrpc/clnt.c
@@ -1862,6 +1862,7 @@ rpc_xdr_encode(struct rpc_task *task)
req->rq_rbuffer,
req->rq_rcvsize);
+ req->rq_reply_bytes_recvd = 0;
req->rq_snd_buf.head[0].iov_len = 0;
xdr_init_encode(&xdr, &req->rq_snd_buf,
req->rq_snd_buf.head[0].iov_base, req);
@@ -1881,6 +1882,8 @@ call_encode(struct rpc_task *task)
if (!rpc_task_need_encode(task))
goto out;
dprint_status(task);
+ /* Dequeue task from the receive queue while we're encoding */
+ xprt_request_dequeue_xprt(task);
/* Encode here so that rpcsec_gss can use correct sequence number. */
rpc_xdr_encode(task);
/* Did the encode result in an error condition? */
@@ -2501,9 +2504,6 @@ call_decode(struct rpc_task *task)
return;
case -EAGAIN:
task->tk_status = 0;
- xdr_free_bvec(&req->rq_rcv_buf);
- req->rq_reply_bytes_recvd = 0;
- req->rq_rcv_buf.len = 0;
if (task->tk_client->cl_discrtry)
xprt_conditional_disconnect(req->rq_xprt,
req->rq_connect_cookie);
diff --git a/net/sunrpc/xprt.c b/net/sunrpc/xprt.c
index 783748d..02d5b21 100644
--- a/net/sunrpc/xprt.c
+++ b/net/sunrpc/xprt.c
@@ -1324,6 +1324,36 @@ xprt_request_dequeue_transmit(struct rpc_task *task)
}
/**
+ * xprt_request_dequeue_xprt - remove a task from the transmit+receive queue
+ * @task: pointer to rpc_task
+ *
+ * Remove a task from the transmit and receive queues, and ensure that
+ * it is not pinned by the receive work item.
+ */
+void
+xprt_request_dequeue_xprt(struct rpc_task *task)
+{
+ struct rpc_rqst *req = task->tk_rqstp;
+ struct rpc_xprt *xprt = req->rq_xprt;
+
+ if (test_bit(RPC_TASK_NEED_XMIT, &task->tk_runstate) ||
+ test_bit(RPC_TASK_NEED_RECV, &task->tk_runstate) ||
+ xprt_is_pinned_rqst(req)) {
+ spin_lock(&xprt->queue_lock);
+ xprt_request_dequeue_transmit_locked(task);
+ xprt_request_dequeue_receive_locked(task);
+ while (xprt_is_pinned_rqst(req)) {
+ set_bit(RPC_TASK_MSG_PIN_WAIT, &task->tk_runstate);
+ spin_unlock(&xprt->queue_lock);
+ xprt_wait_on_pinned_rqst(req);
+ spin_lock(&xprt->queue_lock);
+ clear_bit(RPC_TASK_MSG_PIN_WAIT, &task->tk_runstate);
+ }
+ spin_unlock(&xprt->queue_lock);
+ }
+}
+
+/**
* xprt_request_prepare - prepare an encoded request for transport
* @req: pointer to rpc_rqst
*
@@ -1754,28 +1784,6 @@ void xprt_retry_reserve(struct rpc_task *task)
xprt_do_reserve(xprt, task);
}
-static void
-xprt_request_dequeue_all(struct rpc_task *task, struct rpc_rqst *req)
-{
- struct rpc_xprt *xprt = req->rq_xprt;
-
- if (test_bit(RPC_TASK_NEED_XMIT, &task->tk_runstate) ||
- test_bit(RPC_TASK_NEED_RECV, &task->tk_runstate) ||
- xprt_is_pinned_rqst(req)) {
- spin_lock(&xprt->queue_lock);
- xprt_request_dequeue_transmit_locked(task);
- xprt_request_dequeue_receive_locked(task);
- while (xprt_is_pinned_rqst(req)) {
- set_bit(RPC_TASK_MSG_PIN_WAIT, &task->tk_runstate);
- spin_unlock(&xprt->queue_lock);
- xprt_wait_on_pinned_rqst(req);
- spin_lock(&xprt->queue_lock);
- clear_bit(RPC_TASK_MSG_PIN_WAIT, &task->tk_runstate);
- }
- spin_unlock(&xprt->queue_lock);
- }
-}
-
/**
* xprt_release - release an RPC request slot
* @task: task which is finished with the slot
@@ -1795,7 +1803,7 @@ void xprt_release(struct rpc_task *task)
}
xprt = req->rq_xprt;
- xprt_request_dequeue_all(task, req);
+ xprt_request_dequeue_xprt(task);
spin_lock(&xprt->transport_lock);
xprt->ops->release_xprt(xprt, task);
if (xprt->ops->release_request)
