From: Trond Myklebust trondmy@gmail.com
commit cc204d01262a69218b2d0db5cdea371de85871d9 upstream.
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 Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- include/linux/sunrpc/xprt.h | 1 net/sunrpc/clnt.c | 6 ++-- net/sunrpc/xprt.c | 54 +++++++++++++++++++++++++------------------- 3 files changed, 35 insertions(+), 26 deletions(-)
--- a/include/linux/sunrpc/xprt.h +++ b/include/linux/sunrpc/xprt.h @@ -352,6 +352,7 @@ bool xprt_prepare_transmit(struct rpc_ 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); --- 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? */ @@ -2518,9 +2521,6 @@ 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); --- a/net/sunrpc/xprt.c +++ b/net/sunrpc/xprt.c @@ -1324,6 +1324,36 @@ xprt_request_dequeue_transmit(struct rpc }
/** + * 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 * @@ -1747,28 +1777,6 @@ void xprt_retry_reserve(struct rpc_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 @@ -1788,7 +1796,7 @@ 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)