On Mon, Jun 21, 2021 at 09:46:09PM +0530, Manivannan Sadhasivam wrote:
From: Bhaumik Bhatt bbhatt@codeaurora.org
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.
Cc: stable@vger.kernel.org Fixes: 1d3173a3bae7 ("bus: mhi: core: Add support for processing events from client device") Signed-off-by: Bhaumik Bhatt bbhatt@codeaurora.org Reviewed-by: Hemant Kumar hemantk@codeaurora.org Reviewed-by: Manivannan Sadhasivam manivannan.sadhasivam@linaro.org Reviewed-by: Jeffrey Hugo quic_jhugo@quicinc.com Link: https://lore.kernel.org/r/1619481538-4435-1-git-send-email-bbhatt@codeaurora... Signed-off-by: Manivannan Sadhasivam manivannan.sadhasivam@linaro.org
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 22acde118bc3..ed07421c4870 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);
What can ever trigger this WARN_ON()? Do you mean to reboot a machine if panic-on-warn is set?
If this can actually happen, then check for it and recover properly, don't just blindly warn and then keep on going.
thanks,
greg k-h