[bug report] Revert "media: staging: atomisp: Remove driver"

[Dan Carpenter <dan.carpenter@oracle.com>]

Hello Mauro Carvalho Chehab,

The patch ad85094b293e: "Revert "media: staging: atomisp: Remove
driver"" from Apr 19, 2020, leads to the following static checker
warning:

	drivers/staging/media/atomisp/pci/atomisp_acc.c:207 atomisp_acc_load_to_pipe()
	warn: pointer comes from user 'acc_fw->fw->blob.code'

drivers/staging/media/atomisp/pci/atomisp_acc.c
   168  
   169          acc_fw = acc_alloc_fw(user_fw->size);
   170          if (!acc_fw)
   171                  return -ENOMEM;
   172  
   173          if (copy_from_user(acc_fw->fw, user_fw->data, user_fw->size)) {
                                   ^^^^^^^^^^
The acc_fw->fw->blob.code pointer isn't annotated as __user data.
Eventually it gets passed as "data" to int hmm_store() and treated as
a kernel pointer.

Presumably only privileged users can load new firmware so this isn't
a serious security bug...

   174                  acc_free_fw(acc_fw);
   175                  return -EFAULT;
   176          }
   177  
   178          handle = ida_alloc(&asd->acc.ida, GFP_KERNEL);
   179          if (handle < 0) {
   180                  acc_free_fw(acc_fw);
   181                  return -ENOSPC;
   182          }
   183  
   184          user_fw->fw_handle = handle;
   185          acc_fw->handle = handle;
   186          acc_fw->flags = user_fw->flags;
   187          acc_fw->type = user_fw->type;
   188          acc_fw->fw->handle = handle;
   189  
   190          /*
   191           * correct isp firmware type in order ISP firmware can be appended
   192           * to correct pipe properly
   193           */
   194          if (acc_fw->fw->type == ia_css_isp_firmware) {
   195                  static const int type_to_css[] = {
   196                          [ATOMISP_ACC_FW_LOAD_TYPE_OUTPUT] =
   197                          IA_CSS_ACC_OUTPUT,
   198                          [ATOMISP_ACC_FW_LOAD_TYPE_VIEWFINDER] =
   199                          IA_CSS_ACC_VIEWFINDER,
   200                          [ATOMISP_ACC_FW_LOAD_TYPE_STANDALONE] =
   201                          IA_CSS_ACC_STANDALONE,
   202                  };
   203                  acc_fw->fw->info.isp.type = type_to_css[acc_fw->type];
   204          }
   205  
   206          list_add_tail(&acc_fw->list, &asd->acc.fw);
   207          return 0;
   208  }

regards,
dan carpenter