On 05/11/2024 08:54, 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: stable@vger.kernel.org
> Fixes: d96d3f30c0f2 ("[media] media: venus: hfi: add Venus HFI files")
> Signed-off-by: Vikash Garodia <quic_vgarodia@quicinc.com>
> ---
> 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 f9437b6412b91c2483670a2b11f4fd43f3206404..50d92214190d88eff273a5ba3f95486f758bcc05 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();
>
>
You have this same calculation in venus_set_qhdr_defaults() really needs
a macro or something to stop repeating the same code in another patch later.
Reviewed-by: Bryan O'Donoghue <bryan.odonoghue@linaro.org>