[PATCH] RDMA/rxe: Fix responder length checking for UD request packets

Honggang LI
2024-05-23T09:47:12Z

According to the IBA specification:
If a UD request packet is detected with an invalid length, the request
shall be an invalid request and it shall be silently dropped by
the responder. The responder then waits for a new request packet.

commit 689c5421bfe0 ("RDMA/rxe: Fix incorrect responder length checking")
defers responder length check for UD QPs in function `copy_data`.
But it introduces a regression issue for UD QPs.

When the packet size is too large to fit in the receive buffer.
`copy_data` will return error code -EINVAL. Then `send_data_in`
will return RESPST_ERR_MALFORMED_WQE. UD QP will transfer into
ERROR state.

Fixes: 689c5421bfe0 ("RDMA/rxe: Fix incorrect responder length checking")
Signed-off-by: Honggang LI <honggangli@163.com>
---
drivers/infiniband/sw/rxe/rxe_resp.c | 12 ++++++++++++
1 file changed, 12 insertions(+)

diff --git a/drivers/infiniband/sw/rxe/rxe_resp.c b/drivers/infiniband/sw/rxe/rxe_resp.c
index 963382f625d7..a74f29dcfdc9 100644
--- a/drivers/infiniband/sw/rxe/rxe_resp.c
+++ b/drivers/infiniband/sw/rxe/rxe_resp.c
@@ -354,6 +354,18 @@ static enum resp_states rxe_resp_check_length(struct rxe_qp *qp,
* receive buffer later. For rmda operations additional
* length checks are performed in check_rkey.
*/
+ if ((qp_type(qp) == IB_QPT_GSI) || (qp_type(qp) == IB_QPT_UD)) {
+ unsigned int recv_buffer_len = 0;
+ unsigned int payload = payload_size(pkt);
+
+ for (int i = 0; i < qp->resp.wqe->dma.num_sge; i++)
+ recv_buffer_len += qp->resp.wqe->dma.sge[i].length;
+ if (payload + 40 > recv_buffer_len) {
+ rxe_dbg_qp(qp, "The receive buffer is too small for this UD packet.\n");
+ return RESPST_ERR_LENGTH;
+ }
+ }
+
if (pkt->mask & RXE_PAYLOAD_MASK && ((qp_type(qp) == IB_QPT_RC) ||
(qp_type(qp) == IB_QPT_UC))) {
unsigned int mtu = qp->mtu;
--
2.45.1