From: Hemant Kumar <[email protected]> MHI data completion handler function reads channel id from event ring element. Value is under the control of MHI devices and can be any value between 0 and 255. In order to prevent out of bound access add a bound check against the max channel supported by controller and skip processing of that event ring element.
Signed-off-by: Hemant Kumar <[email protected]> Signed-off-by: Bhaumik Bhatt <[email protected]> Reviewed-by: Jeffrey Hugo <[email protected]> --- drivers/bus/mhi/core/main.c | 40 +++++++++++++++++++++++++++++----------- 1 file changed, 29 insertions(+), 11 deletions(-) diff --git a/drivers/bus/mhi/core/main.c b/drivers/bus/mhi/core/main.c index 605640c..30798ec 100644 --- a/drivers/bus/mhi/core/main.c +++ b/drivers/bus/mhi/core/main.c @@ -775,9 +775,18 @@ int mhi_process_ctrl_ev_ring(struct mhi_controller *mhi_cntrl, } case MHI_PKT_TYPE_TX_EVENT: chan = MHI_TRE_GET_EV_CHID(local_rp); - mhi_chan = &mhi_cntrl->mhi_chan[chan]; - parse_xfer_event(mhi_cntrl, local_rp, mhi_chan); - event_quota--; + + WARN_ON(chan >= mhi_cntrl->max_chan); + + /* + * Only process the event ring elements whose channel + * ID is within the maximum supported range. + */ + if (chan < mhi_cntrl->max_chan) { + mhi_chan = &mhi_cntrl->mhi_chan[chan]; + parse_xfer_event(mhi_cntrl, local_rp, mhi_chan); + event_quota--; + } break; default: dev_err(dev, "Unhandled event type: %d\n", type); @@ -820,14 +829,23 @@ int mhi_process_data_event_ring(struct mhi_controller *mhi_cntrl, enum mhi_pkt_type type = MHI_TRE_GET_EV_TYPE(local_rp); chan = MHI_TRE_GET_EV_CHID(local_rp); - mhi_chan = &mhi_cntrl->mhi_chan[chan]; - - if (likely(type == MHI_PKT_TYPE_TX_EVENT)) { - parse_xfer_event(mhi_cntrl, local_rp, mhi_chan); - event_quota--; - } else if (type == MHI_PKT_TYPE_RSC_TX_EVENT) { - parse_rsc_event(mhi_cntrl, local_rp, mhi_chan); - event_quota--; + + WARN_ON(chan >= mhi_cntrl->max_chan); + + /* + * Only process the event ring elements whose channel + * ID is within the maximum supported range. + */ + if (chan < mhi_cntrl->max_chan) { + mhi_chan = &mhi_cntrl->mhi_chan[chan]; + + if (likely(type == MHI_PKT_TYPE_TX_EVENT)) { + parse_xfer_event(mhi_cntrl, local_rp, mhi_chan); + event_quota--; + } else if (type == MHI_PKT_TYPE_RSC_TX_EVENT) { + parse_rsc_event(mhi_cntrl, local_rp, mhi_chan); + event_quota--; + } } mhi_recycle_ev_ring_element(mhi_cntrl, ev_ring); -- The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum, a Linux Foundation Collaborative Project
