On Fri, Mar 24, 2023 at 10:13:04AM -0600, Jeffrey Hugo wrote:
> If the value read from the CHDBOFF and ERDBOFF registers is outside the
> range of the MHI register space then an invalid address might be computed
> which later causes a kernel panic. Range check the read value to prevent
> a crash due to bad data from the device.
>
> Fixes: 6cd330ae76ff ("bus: mhi: core: Add support for ringing channel/event ring doorbells")
> Cc: stable@xxxxxxxxxxxxxxx
> Signed-off-by: Jeffrey Hugo <quic_jhugo@xxxxxxxxxxx>
Reviewed-by: Manivannan Sadhasivam <mani@xxxxxxxxxx>
Thanks,
Mani
> Reviewed-by: Pranjal Ramajor Asha Kanojiya <quic_pkanojiy@xxxxxxxxxxx>
> ---
>
> v2:
> -CC stable
> -Use ERANGE for the error code
>
> drivers/bus/mhi/host/init.c | 12 ++++++++++++
> 1 file changed, 12 insertions(+)
>
> diff --git a/drivers/bus/mhi/host/init.c b/drivers/bus/mhi/host/init.c
> index 3d779ee..b46a082 100644
> --- a/drivers/bus/mhi/host/init.c
> +++ b/drivers/bus/mhi/host/init.c
> @@ -516,6 +516,12 @@ int mhi_init_mmio(struct mhi_controller *mhi_cntrl)
> return -EIO;
> }
>
> + if (val >= mhi_cntrl->reg_len - (8 * MHI_DEV_WAKE_DB)) {
> + dev_err(dev, "CHDB offset: 0x%x is out of range: 0x%zx\n",
> + val, mhi_cntrl->reg_len - (8 * MHI_DEV_WAKE_DB));
> + return -ERANGE;
> + }
> +
> /* Setup wake db */
> mhi_cntrl->wake_db = base + val + (8 * MHI_DEV_WAKE_DB);
> mhi_cntrl->wake_set = false;
> @@ -532,6 +538,12 @@ int mhi_init_mmio(struct mhi_controller *mhi_cntrl)
> return -EIO;
> }
>
> + if (val >= mhi_cntrl->reg_len - (8 * mhi_cntrl->total_ev_rings)) {
> + dev_err(dev, "ERDB offset: 0x%x is out of range: 0x%zx\n",
> + val, mhi_cntrl->reg_len - (8 * mhi_cntrl->total_ev_rings));
> + return -ERANGE;
> + }
> +
> /* Setup event db address for each ev_ring */
> mhi_event = mhi_cntrl->mhi_event;
> for (i = 0; i < mhi_cntrl->total_ev_rings; i++, val += 8, mhi_event++) {
> --
> 2.7.4
>
>
--
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