6.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Harry Wentland commit 4f40873f8a4107df2b9c8e68c947c4fd0cd519d2 upstream. __is_lut_linear() computes the expected value of each entry with expected = i * MAX_DRM_LUT_VALUE / (size - 1); If it is ever called with a single-entry LUT, size - 1 is zero and the kernel takes a divide error (#DE). A LUT with fewer than two entries cannot describe a linear mapping anyway, so return false early instead of dividing by zero. Fixes: 086247a4b2fb ("drm/amd/display: Use 4096 lut entries") Cc: stable@vger.kernel.org Signed-off-by: Harry Wentland Reviewed-by: Melissa Wen Tested-by: Daniel Wheeler Signed-off-by: Alex Deucher Signed-off-by: Greg Kroah-Hartman --- drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_color.c | 6 ++++++ 1 file changed, 6 insertions(+) --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_color.c +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_color.c @@ -360,6 +360,12 @@ static bool __is_lut_linear(const struct uint32_t expected; int delta; + /* A LUT with fewer than two entries can't be interpolated and would + * divide by zero below (size - 1); it can't be treated as linear. + */ + if (size < 2) + return false; + for (i = 0; i < size; i++) { /* All color values should equal */ if ((lut[i].red != lut[i].green) || (lut[i].green != lut[i].blue))