Messages in this thread Patch in this message | | | From | Bhaumik Bhatt <> | Subject | [PATCH] bus: mhi: core: Validate channel ID when processing command completions | Date | Mon, 26 Apr 2021 16:58:58 -0700 |
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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@codeaurora.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 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
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