On Wed, Dec 25, 2019 at 12:55:35PM +0800, Frank Huang wrote:
> hi, there is a panic on rdma_rxe module when the restart
> network.service or shutdown the switch.
>
> it looks like a use-after-free error.
>
> everytime it happens, there is the log "rdma_rxe: Unknown layer 3 protocol: 0"
The error print itself is harmless.
>
> is it a known error?
>
> my kernel version is 4.14.97
Your kernel is old enough and doesn't include refcount,
so I can't say for sure that it is the case, but the
following code is not correct and with refcount debug
it will be seen immediately.
1213 int rxe_responder(void *arg)
1214 {
1215 struct rxe_qp *qp = (struct rxe_qp *)arg;
1216 struct rxe_dev *rxe = to_rdev(qp->ibqp.device);
1217 enum resp_states state;
1218 struct rxe_pkt_info *pkt = NULL;
1219 int ret = 0;
1220
1221 rxe_add_ref(qp); <------ USE-AFTER-FREE
1222
1223 qp->resp.aeth_syndrome = AETH_ACK_UNLIMITED;
1224
1225 if (!qp->valid) {
1226 ret = -EINVAL;
1227 goto done;
1228 }
Thanks
