On Wed, 22 Dec 2021, Jani Nikula <jani.nikula@xxxxxxxxx> wrote:
> If VBT size is not a multiple of 4, the last 4-byte store will be out of
> bounds of the allocated buffer. Spotted with KASAN. Round up the
> allocation size.
>
> v2: Use round_up() intead of roundup() as it's a power of 2 (Thomas)
>
> Reported-by: Thomas Hellström <thomas.hellstrom@xxxxxxxxxxxxxxx>
> Fixes: a36e7dc0af1c ("drm/i915/dg1: Read OPROM via SPI controller")
> Cc: Clint Taylor <clinton.a.taylor@xxxxxxxxx>
> Cc: Lucas De Marchi <lucas.demarchi@xxxxxxxxx>
> Reviewed-by: Thomas Hellström <thomas.hellstrom@xxxxxxxxxxxxxxx>
> Signed-off-by: Jani Nikula <jani.nikula@xxxxxxxxx>
Pushed, thanks for the report and review.
BR,
Jani.
> ---
> drivers/gpu/drm/i915/display/intel_bios.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/i915/display/intel_bios.c b/drivers/gpu/drm/i915/display/intel_bios.c
> index 76a8f001f4c4..c7a8d517ce81 100644
> --- a/drivers/gpu/drm/i915/display/intel_bios.c
> +++ b/drivers/gpu/drm/i915/display/intel_bios.c
> @@ -2369,7 +2369,7 @@ static struct vbt_header *spi_oprom_get_vbt(struct drm_i915_private *i915)
> vbt_size = intel_uncore_read(&i915->uncore, PRIMARY_SPI_TRIGGER);
> vbt_size &= 0xffff;
>
> - vbt = kzalloc(vbt_size, GFP_KERNEL);
> + vbt = kzalloc(round_up(vbt_size, 4), GFP_KERNEL);
> if (!vbt)
> goto err_not_found;
--
Jani Nikula, Intel Open Source Graphics Center
