On Sat, Mar 29, 2025 at 02:53:22PM -0700, Luis Chamberlain wrote:
> On Fri, Mar 21, 2025 at 05:35:18PM +0300, Dan Carpenter wrote:
> > On Mon, Aug 06, 2018 at 11:42:57PM +0300, Dan Carpenter wrote:
> > > Hello Martin Blumenstingl,
> > >
> > > The patch 26503ad25de8: "Bluetooth: btrtl: split the device
> > > initialization into smaller parts" from Aug 2, 2018, leads to the
> > > following static checker warning:
> > >
> > > drivers/bluetooth/btrtl.c:592 btrtl_initialize()
> > > warn: passing zero to 'ERR_PTR'
> > >
> > > drivers/bluetooth/btrtl.c
> > > 559 btrtl_dev->fw_len = rtl_load_file(hdev, btrtl_dev->ic_info->fw_name,
> > > 560 &btrtl_dev->fw_data);
> > > 561 if (btrtl_dev->fw_len < 0) {
> > > 562 rtl_dev_err(hdev, "firmware file %s not found\n",
> > > 563 btrtl_dev->ic_info->fw_name);
> > > 564 ret = btrtl_dev->fw_len;
> > > 565 goto err_free;
> > > 566 }
> > > 567
> > > 568 if (btrtl_dev->ic_info->cfg_name) {
> > > 569 if (postfix) {
> > > 570 snprintf(cfg_name, sizeof(cfg_name), "%s-%s.bin",
> > > 571 btrtl_dev->ic_info->cfg_name, postfix);
> > > 572 } else {
> > > 573 snprintf(cfg_name, sizeof(cfg_name), "%s.bin",
> > > 574 btrtl_dev->ic_info->cfg_name);
> > > 575 }
> > > 576 btrtl_dev->cfg_len = rtl_load_file(hdev, cfg_name,
> > > 577 &btrtl_dev->cfg_data);
> > > 578 if (btrtl_dev->ic_info->config_needed &&
> > > 579 btrtl_dev->cfg_len <= 0) {
> > > ^^^^^^^^^^^^^^^^^^^^^^^
> > > Assume btrtl_dev->cfg_len == 0
> > >
> >
> > This is the length of the firmware file. Does it make sense for
> > request_firmware() to load empty files? Probably there is a test for
> > this in the firmware code which rejects zero length files?
>
> We don't know the size of the file until we try to read it. Although
> kernel_read_file_from_path_initns() perhaps should allow for empty
> files, I do agree it seems odd to use the firmware API for 0 length
> files.
>
> We should extend tools/testing/selftests/firmware/ to check for this.
> Care for a patch?
I was hoping that maybe the code already existed and I just hadn't seen
it. I wouldn't have the foggiest idea how to write it myself. This code
returns 0 if there is a zero length file and that results in a NULL
dereference. I've sent a fix for that.
regards,
dan carpenter
