From: Sean Hefty Date: Wed, 21 Jul 2010 23:36:52 +0000 (+0000) Subject: IB/cm: Check LAP state before sending an MRA X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=50a025c69ee749d822c301f9bf63dee13c113680;p=linux-beck.git IB/cm: Check LAP state before sending an MRA NULL pointer dereferences in ib_cm_init_qp_attr() were seen by some users. From a crash dump, I determined that we died in cm_init_qp_rts_attr() (it's inlined, so it doesn't show up in the traceback) on the line labeled below: static int cm_init_qp_rts_attr(struct cm_id_private *cm_id_priv, struct ib_qp_attr *qp_attr, int *qp_attr_mask) { ........ if (cm_id_priv->id.lap_state == IB_CM_LAP_UNINIT) { ..... } else { *qp_attr_mask = IB_QP_ALT_PATH | IB_QP_PATH_MIG_STATE; qp_attr->alt_port_num = cm_id_priv->alt_av.port->port_num; <-die The problem is that the rdma_cm can call ib_send_cm_mra() after a connection has been established. The ib_cm incorrectly assumes that the MRA is in response to a LAP (load alternate path) message, even though no LAP message has been received. The ib_cm needs to check the lap_state before sending an MRA if the cm_id state is established. Reported-by: Arthur Kepner Reported-by: Josh England Signed-off-by: Sean Hefty Signed-off-by: Roland Dreier --- diff --git a/drivers/infiniband/core/cm.c b/drivers/infiniband/core/cm.c index ad63b79afac1..64e0903091a8 100644 --- a/drivers/infiniband/core/cm.c +++ b/drivers/infiniband/core/cm.c @@ -2409,10 +2409,12 @@ int ib_send_cm_mra(struct ib_cm_id *cm_id, msg_response = CM_MSG_RESPONSE_REP; break; case IB_CM_ESTABLISHED: - cm_state = cm_id->state; - lap_state = IB_CM_MRA_LAP_SENT; - msg_response = CM_MSG_RESPONSE_OTHER; - break; + if (cm_id->lap_state == IB_CM_LAP_RCVD) { + cm_state = cm_id->state; + lap_state = IB_CM_MRA_LAP_SENT; + msg_response = CM_MSG_RESPONSE_OTHER; + break; + } default: ret = -EINVAL; goto error1;