On Tue, Nov 05, 2024 at 02:24:57PM +0530, Vikash Garodia wrote:
> sfr->buf_size is in shared memory and can be modified by malicious user.
> OOB write is possible when the size is made higher than actual sfr data
> buffer.
>
> Cc: stable@xxxxxxxxxxxxxxx
> Fixes: d96d3f30c0f2 ("[media] media: venus: hfi: add Venus HFI files")
> Signed-off-by: Vikash Garodia <quic_vgarodia@xxxxxxxxxxx>
> ---
> drivers/media/platform/qcom/venus/hfi_venus.c | 9 +++++++--
> 1 file changed, 7 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/media/platform/qcom/venus/hfi_venus.c b/drivers/media/platform/qcom/venus/hfi_venus.c
> index 50d92214190d88eff273a5ba3f95486f758bcc05..c19d6bf686d0f31c6a2f551de3f7eb08031bde85 100644
> --- a/drivers/media/platform/qcom/venus/hfi_venus.c
> +++ b/drivers/media/platform/qcom/venus/hfi_venus.c
> @@ -1041,18 +1041,23 @@ static void venus_sfr_print(struct venus_hfi_device *hdev)
> {
> struct device *dev = hdev->core->dev;
> struct hfi_sfr *sfr = hdev->sfr.kva;
> + u32 size;
> void *p;
>
> if (!sfr)
> return;
>
> - p = memchr(sfr->data, '\0', sfr->buf_size);
> + size = sfr->buf_size;
> + if (size > ALIGNED_SFR_SIZE)
> + return;
Why can't you just limit size to ALIGNED_SFR_SIZE, still allowing the
data to be captured?
> +
> + p = memchr(sfr->data, '\0', size);
> /*
> * SFR isn't guaranteed to be NULL terminated since SYS_ERROR indicates
> * that Venus is in the process of crashing.
> */
> if (!p)
> - sfr->data[sfr->buf_size - 1] = '\0';
> + sfr->data[size - 1] = '\0';
>
> dev_err_ratelimited(dev, "SFR message from FW: %s\n", sfr->data);
> }
>
> --
> 2.34.1
>
--
With best wishes
Dmitry
