On Mon, Apr 26, 2021 at 04:58:58PM -0700, Bhaumik Bhatt wrote:
> MHI reads the channel ID from the event ring element sent by the
> device which can be any value between 0 and 255. In order to
> prevent any out of bound accesses, add a check against the maximum
> number of channels supported by the controller and those channels
> not configured yet so as to skip processing of that event ring
> element.
>
> Fixes: 1d3173a3bae7 ("bus: mhi: core: Add support for processing events from client device")
> Signed-off-by: Bhaumik Bhatt <bbhatt@xxxxxxxxxxxxxx>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@xxxxxxxxxx>
Thanks,
Mani
> ---
> drivers/bus/mhi/core/main.c | 15 ++++++++++-----
> 1 file changed, 10 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/bus/mhi/core/main.c b/drivers/bus/mhi/core/main.c
> index 22acde1..ed07421 100644
> --- a/drivers/bus/mhi/core/main.c
> +++ b/drivers/bus/mhi/core/main.c
> @@ -773,11 +773,16 @@ static void mhi_process_cmd_completion(struct mhi_controller *mhi_cntrl,
> cmd_pkt = mhi_to_virtual(mhi_ring, ptr);
>
> chan = MHI_TRE_GET_CMD_CHID(cmd_pkt);
> - mhi_chan = &mhi_cntrl->mhi_chan[chan];
> - write_lock_bh(&mhi_chan->lock);
> - mhi_chan->ccs = MHI_TRE_GET_EV_CODE(tre);
> - complete(&mhi_chan->completion);
> - write_unlock_bh(&mhi_chan->lock);
> + WARN_ON(chan >= mhi_cntrl->max_chan);
> +
> + if (chan < mhi_cntrl->max_chan &&
> + mhi_cntrl->mhi_chan[chan].configured) {
> + mhi_chan = &mhi_cntrl->mhi_chan[chan];
> + write_lock_bh(&mhi_chan->lock);
> + mhi_chan->ccs = MHI_TRE_GET_EV_CODE(tre);
> + complete(&mhi_chan->completion);
> + write_unlock_bh(&mhi_chan->lock);
> + }
>
> mhi_del_ring_element(mhi_cntrl, mhi_ring);
> }
> --
> The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
> a Linux Foundation Collaborative Project
>
