[media.git/next] media: venus: hfi: add check to handle incorrect queue size

[media-ci]

On Thu Feb 20 22:50:10 2025 +0530, Vikash Garodia wrote:
> qsize represents size of shared queued between driver and video
> firmware. Firmware can modify this value to an invalid large value. In
> such situation, empty_space will be bigger than the space actually
> available. Since new_wr_idx is not checked, so the following code will
> result in an OOB write.
> ...
> qsize = qhdr->q_size
> 
> if (wr_idx >= rd_idx)
>  empty_space = qsize - (wr_idx - rd_idx)
> ....
> if (new_wr_idx < qsize) {
>  memcpy(wr_ptr, packet, dwords << 2) --> OOB write
> 
> Add check to ensure qsize is within the allocated size while
> reading and writing packets into the queue.
> 
> Cc: sta...@vger.kernel.org
> Fixes: d96d3f30c0f2 ("[media] media: venus: hfi: add Venus HFI files")
> Reviewed-by: Bryan O'Donoghue <bryan.odonog...@linaro.org>
> Signed-off-by: Vikash Garodia <quic_vgaro...@quicinc.com>
> Signed-off-by: Hans Verkuil <hverk...@xs4all.nl>

Patch committed.

Thanks,
Hans Verkuil

 drivers/media/platform/qcom/venus/hfi_venus.c | 6 ++++++
 1 file changed, 6 insertions(+)

---

diff --git a/drivers/media/platform/qcom/venus/hfi_venus.c 
b/drivers/media/platform/qcom/venus/hfi_venus.c
index a9167867063c..36d3a37db4e8 100644
--- a/drivers/media/platform/qcom/venus/hfi_venus.c
+++ b/drivers/media/platform/qcom/venus/hfi_venus.c
@@ -187,6 +187,9 @@ static int venus_write_queue(struct venus_hfi_device *hdev,
        /* ensure rd/wr indices's are read from memory */
        rmb();
 
+       if (qsize > IFACEQ_QUEUE_SIZE / 4)
+               return -EINVAL;
+
        if (wr_idx >= rd_idx)
                empty_space = qsize - (wr_idx - rd_idx);
        else
@@ -255,6 +258,9 @@ static int venus_read_queue(struct venus_hfi_device *hdev,
        wr_idx = qhdr->write_idx;
        qsize = qhdr->q_size;
 
+       if (qsize > IFACEQ_QUEUE_SIZE / 4)
+               return -EINVAL;
+
        /* make sure data is valid before using it */
        rmb();