CVE-2023-26242: fpga: dfl-afu-region: Add overflow checks for region size and offset

@@ -151,12 +151,17 @@ int afu_mmio_region_get_by_offset(struct dfl_feature_platform_data *pdata, struct dfl_afu_mmio_region *region; struct dfl_afu *afu; int ret = 0;

• u64 region_size = 0;

  mutex_lock(&pdata->lock);

• if (check_add_overflow(offset, size, &region_size)) {

•   ret = -EINVAL;
  

•   goto exit;
  

• } afu = dfl_fpga_pdata_get_private(pdata); for_each_region(region, afu) if (region->offset <= offset && - region->offset + region->size >= offset + size) {

•       region->offset + region->size >= region\_size) {
        \*pregion = \*region;
        goto exit;
    }