On Fri, Dec 9, 2022 6:10 AM Bob Pearson wrote:
> The code in rxe_resp.c at check_length() is incorrect as it
> compares pkt->opcode an 8 bit value against various mask bits
> which are all higher than 256 so nothing is ever reported.
>
> This patch rewrites this to compare against pkt->mask which is
> correct. However this now exposes another error. For UD send
> packets the value of the pmtu cannot be determined from qp->mtu.
> All that is required here is to later check if the payload fits
> into the posted receive buffer in that case.
>
> Fixes: 837a55847ead ("RDMA/rxe: Implement packet length validation on responder")
> Signed-off-by: Bob Pearson <rpearsonhpe@xxxxxxxxx>
Looks good. Thank you for the fix.
Reviewed-by: Daisuke Matsuda <matsuda-daisuke@xxxxxxxxxxx>
> ---
> drivers/infiniband/sw/rxe/rxe_resp.c | 62 ++++++++++++++++------------
> 1 file changed, 36 insertions(+), 26 deletions(-)
>
> diff --git a/drivers/infiniband/sw/rxe/rxe_resp.c b/drivers/infiniband/sw/rxe/rxe_resp.c
> index 6ac544477f3f..42261537772c 100644
> --- a/drivers/infiniband/sw/rxe/rxe_resp.c
> +++ b/drivers/infiniband/sw/rxe/rxe_resp.c
> @@ -392,36 +392,46 @@ static enum resp_states check_resource(struct rxe_qp *qp,
> return RESPST_CHK_LENGTH;
> }
>
> -static enum resp_states check_length(struct rxe_qp *qp,
> - struct rxe_pkt_info *pkt)
> +static enum resp_states rxe_resp_check_length(struct rxe_qp *qp,
> + struct rxe_pkt_info *pkt)
> {
> - int mtu = qp->mtu;
> - u32 payload = payload_size(pkt);
> - u32 dmalen = reth_len(pkt);
> -
> - /* RoCEv2 packets do not have LRH.
> - * Let's skip checking it.
> + /*
> + * See IBA C9-92
> + * For UD QPs we only check if the packet will fit in the
> + * receive buffer later. For rmda operations additional
> + * length checks are performed in check_rkey.
> */
> -
> - if ((pkt->opcode & RXE_START_MASK) &&
> - (pkt->opcode & RXE_END_MASK)) {
> - /* "only" packets */
> - if (payload > mtu)
> - return RESPST_ERR_LENGTH;
> - } else if ((pkt->opcode & RXE_START_MASK) ||
> - (pkt->opcode & RXE_MIDDLE_MASK)) {
> - /* "first" or "middle" packets */
> - if (payload != mtu)
> - return RESPST_ERR_LENGTH;
> - } else if (pkt->opcode & RXE_END_MASK) {
> - /* "last" packets */
> - if ((payload == 0) || (payload > mtu))
> - 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;
> + unsigned int payload = payload_size(pkt);
> +
> + if ((pkt->mask & RXE_START_MASK) &&
> + (pkt->mask & RXE_END_MASK)) {
> + if (unlikely(payload > mtu)) {
> + rxe_dbg_qp(qp, "only packet too long");
> + return RESPST_ERR_LENGTH;
> + }
> + } else if ((pkt->mask & RXE_START_MASK) ||
> + (pkt->mask & RXE_MIDDLE_MASK)) {
> + if (unlikely(payload != mtu)) {
> + rxe_dbg_qp(qp, "first or middle packet not mtu");
> + return RESPST_ERR_LENGTH;
> + }
> + } else if (pkt->mask & RXE_END_MASK) {
> + if (unlikely((payload == 0) || (payload > mtu))) {
> + rxe_dbg_qp(qp, "last packet zero or too long");
> + return RESPST_ERR_LENGTH;
> + }
> + }
> }
>
> - if (pkt->opcode & (RXE_WRITE_MASK | RXE_READ_MASK)) {
> - if (dmalen > (1 << 31))
> + /* See IBA C9-94 */
> + if (pkt->mask & RXE_RETH_MASK) {
> + if (reth_len(pkt) > (1U << 31)) {
> + rxe_dbg_qp(qp, "dma length too long");
> return RESPST_ERR_LENGTH;
> + }
> }
>
> return RESPST_CHK_RKEY;
> @@ -1397,7 +1407,7 @@ int rxe_responder(void *arg)
> state = check_resource(qp, pkt);
> break;
> case RESPST_CHK_LENGTH:
> - state = check_length(qp, pkt);
> + state = rxe_resp_check_length(qp, pkt);
> break;
> case RESPST_CHK_RKEY:
> state = check_rkey(qp, pkt);
> --
> 2.37.2
