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: 7536908982 ("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>
This commit is contained in:
Trond Myklebust 2019-09-10 13:01:35 -04:00 committed by Anna Schumaker
parent 98ef77d1aa
commit cc204d0126
3 changed files with 35 additions and 26 deletions

View File

@ -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);

View File

@ -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);

View File

@ -1323,6 +1323,36 @@ xprt_request_dequeue_transmit(struct rpc_task *task)
spin_unlock(&xprt->queue_lock);
}
/**
* 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)