From: Harshit Mogalapalli Date: Fri, 10 Dec 2021 04:41:24 +0000 (-0800) Subject: drm/i915/display: Fix an unsigned subtraction which can never be negative. X-Git-Tag: v5.16-rc6~22^2~2^2 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=53b3495273282aa844c4613d19c3b30558c70c84;p=thirdparty%2Fkernel%2Flinux.git drm/i915/display: Fix an unsigned subtraction which can never be negative. smatch warning: drivers/gpu/drm/i915/display/intel_dmc.c:601 parse_dmc_fw() warn: unsigned 'fw->size - offset' is never less than zero Firmware size is size_t and offset is u32. So the subtraction is unsigned which can never be less than zero. Fixes: 3d5928a168a9 ("drm/i915/xelpd: Pipe A DMC plugging") Signed-off-by: Harshit Mogalapalli Reviewed-by: Lucas De Marchi Signed-off-by: Lucas De Marchi Link: https://patchwork.freedesktop.org/patch/msgid/20211210044129.12422-1-harshit.m.mogalapalli@oracle.com (cherry picked from commit 87bb2a410dcfb617b88e4695edf4beb6336dc314) Signed-off-by: Rodrigo Vivi --- diff --git a/drivers/gpu/drm/i915/display/intel_dmc.c b/drivers/gpu/drm/i915/display/intel_dmc.c index 2dc9d632969db..aef69522f0be3 100644 --- a/drivers/gpu/drm/i915/display/intel_dmc.c +++ b/drivers/gpu/drm/i915/display/intel_dmc.c @@ -596,7 +596,7 @@ 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 (offset > fw->size) { drm_err(&dev_priv->drm, "Reading beyond the fw_size\n"); continue; }