On Tue, Jul 20, 2021 at 04:57:26PM +0100, Colin King wrote:

From: Colin Ian King colin.king@canonical.com

The subtraction of fw->size - offset is operating on two unsigned integers and the result is unsigned and hence the less than zero comparison will always to be false. Fix this by casting fw->size from a size_t to a ssize_t to ensure the result can be signed to allow a less than zero result.

Addresses-Coverity: ("Unsigned compared against 0") Fixes: 3d5928a168a9 ("drm/i915/xelpd: Pipe A DMC plugging") Signed-off-by: Colin Ian King colin.king@canonical.com

Reviewed-by: Lucas De Marchi lucas.demarchi@intel.com

thanks Lucas De Marchi

---

drivers/gpu/drm/i915/display/intel_dmc.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/display/intel_dmc.c b/drivers/gpu/drm/i915/display/intel_dmc.c index f8789d4543bf..dde1f243d375 100644 --- a/drivers/gpu/drm/i915/display/intel_dmc.c +++ b/drivers/gpu/drm/i915/display/intel_dmc.c @@ -645,7 +645,7 @@ static void parse_dmc_fw(struct drm_i915_private *dev_priv, continue;

offset = readcount + dmc->dmc_info[id].dmc_offset * 4;

• if (fw->size - offset < 0) {
  

• if ((ssize_t)fw->size - offset < 0) {
  drm_err(&dev_priv->drm, "Reading beyond the fw_size\n");
  continue;
  

  }

-- 2.31.1