From: Manivannan Sadhasivam <mani@kernel.org>
To: Bhaumik Bhatt <bbhatt@codeaurora.org>
Cc: linux-arm-msm@vger.kernel.org, linux-kernel@vger.kernel.org,
hemantk@codeaurora.org, jhugo@codeaurora.org
Subject: Re: [PATCH v6 3/8] bus: mhi: core: Add range check for channel id received in event ring
Date: Fri, 8 May 2020 11:15:18 +0530 [thread overview]
Message-ID: <20200508054518.GA2696@Mani-XPS-13-9360> (raw)
In-Reply-To: <1588718832-4891-4-git-send-email-bbhatt@codeaurora.org>
On Tue, May 05, 2020 at 03:47:07PM -0700, Bhaumik Bhatt wrote:
> From: Hemant Kumar <hemantk@codeaurora.org>
>
> 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 <hemantk@codeaurora.org>
> Signed-off-by: Bhaumik Bhatt <bbhatt@codeaurora.org>
> Reviewed-by: Jeffrey Hugo <jhugo@codeaurora.org>
> ---
> drivers/bus/mhi/core/main.c | 8 ++++++++
> 1 file changed, 8 insertions(+)
>
> diff --git a/drivers/bus/mhi/core/main.c b/drivers/bus/mhi/core/main.c
> index 605640c..e60ab21 100644
> --- a/drivers/bus/mhi/core/main.c
> +++ b/drivers/bus/mhi/core/main.c
> @@ -776,6 +776,9 @@ 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];
Check should be done before this statement, isn't it?
> + if (WARN_ON(chan >= mhi_cntrl->max_chan))
> + goto next_event;
> +
I don't prefer using gotos for non exit paths but I don't have a better solution
here. But you can try to wrap 'WARN_ON' inside the 'MHI_TRE_GET_EV_CHID'
definition and the just use:
/*
* 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;
This looks more clean.
> parse_xfer_event(mhi_cntrl, local_rp, mhi_chan);
> event_quota--;
> break;
> @@ -784,6 +787,7 @@ int mhi_process_ctrl_ev_ring(struct mhi_controller *mhi_cntrl,
> break;
> }
>
> +next_event:
> mhi_recycle_ev_ring_element(mhi_cntrl, ev_ring);
> local_rp = ev_ring->rp;
> dev_rp = mhi_to_virtual(ev_ring, er_ctxt->rp);
So you want the count to get increased for skipped element also?
Thanks,
Mani
> @@ -820,6 +824,9 @@ 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);
> + if (WARN_ON(chan >= mhi_cntrl->max_chan))
> + goto next_event;
> +
> mhi_chan = &mhi_cntrl->mhi_chan[chan];
>
> if (likely(type == MHI_PKT_TYPE_TX_EVENT)) {
> @@ -830,6 +837,7 @@ int mhi_process_data_event_ring(struct mhi_controller *mhi_cntrl,
> event_quota--;
> }
>
> +next_event:
> mhi_recycle_ev_ring_element(mhi_cntrl, ev_ring);
> local_rp = ev_ring->rp;
> dev_rp = mhi_to_virtual(ev_ring, er_ctxt->rp);
> --
> The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
> a Linux Foundation Collaborative Project
>
next prev parent reply other threads:[~2020-05-08 5:45 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-05-05 22:47 [PATCH v6 0/8] Bug fixes and improved logging in MHI Bhaumik Bhatt
2020-05-05 22:47 ` [PATCH v6 1/8] bus: mhi: core: Refactor mhi queue APIs Bhaumik Bhatt
2020-05-05 22:47 ` [PATCH v6 2/8] bus: mhi: core: Cache intmod from mhi event to mhi channel Bhaumik Bhatt
2020-05-05 22:47 ` [PATCH v6 3/8] bus: mhi: core: Add range check for channel id received in event ring Bhaumik Bhatt
2020-05-08 5:45 ` Manivannan Sadhasivam [this message]
2020-05-08 17:34 ` Hemant Kumar
2020-05-08 18:06 ` Manivannan Sadhasivam
2020-05-05 22:47 ` [PATCH v6 4/8] bus: mhi: core: Read transfer length from an event properly Bhaumik Bhatt
2020-05-05 22:47 ` [PATCH v6 5/8] bus: mhi: core: Handle firmware load using state worker Bhaumik Bhatt
2020-05-05 22:47 ` [PATCH v6 6/8] bus: mhi: core: Return appropriate error codes for AMSS load failure Bhaumik Bhatt
2020-05-08 6:13 ` Manivannan Sadhasivam
2020-05-05 22:47 ` [PATCH v6 7/8] bus: mhi: core: Improve debug logs for loading firmware Bhaumik Bhatt
2020-05-05 22:47 ` [PATCH v6 8/8] bus: mhi: core: Ensure non-zero session or sequence ID values are used Bhaumik Bhatt
2020-05-06 0:33 ` Jeffrey Hugo
2020-05-08 6:22 ` Manivannan Sadhasivam
2020-05-08 6:24 ` [PATCH v6 0/8] Bug fixes and improved logging in MHI Manivannan Sadhasivam
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