Hi Wei, > Fault injection test reported memory leak of hci device as follows: > > unreferenced object 0xffff88800b858000 (size 8192): > comm "kworker/0:2", pid 167, jiffies 4294955747 (age 557.148s) > hex dump (first 32 bytes): > 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ > 00 00 00 00 00 00 00 00 00 00 00 00 ad 4e ad de .............N.. > backtrace: > [<0000000070eb1059>] kmem_cache_alloc_trace mm/slub.c:3208 > [<00000000015eb521>] hci_alloc_dev_priv include/linux/slab.h:591 > [<00000000dcfc1e21>] bpa10x_probe include/net/bluetooth/hci_core.h:1240 > [<000000005d3028c7>] usb_probe_interface drivers/usb/core/driver.c:397 > [<00000000cbac9243>] really_probe drivers/base/dd.c:517 > [<0000000024cab3f0>] __driver_probe_device drivers/base/dd.c:751 > [<00000000202135cb>] driver_probe_device drivers/base/dd.c:782 > [<000000000761f2bc>] __device_attach_driver drivers/base/dd.c:899 > [<00000000f7d63134>] bus_for_each_drv drivers/base/bus.c:427 > [<00000000c9551f0b>] __device_attach drivers/base/dd.c:971 > [<000000007f79bd16>] bus_probe_device drivers/base/bus.c:487 > [<000000007bb8b95a>] device_add drivers/base/core.c:3364 > [<000000009564d9ea>] usb_set_configuration drivers/usb/core/message.c:2171 > [<00000000e4657087>] usb_generic_driver_probe drivers/usb/core/generic.c:239 > [<0000000071ede518>] usb_probe_device drivers/usb/core/driver.c:294 > [<00000000cbac9243>] really_probe drivers/base/dd.c:517 > > hci_alloc_dev() do not init the device's flag. And hci_free_dev() > using put_device() to free the memory allocated for this device, > but it calls just kfree(dev) only in case of HCI_UNREGISTER flag > is set. So any error handing before hci_register_dev() success > will cause memory leak. > > To avoid this behaviour we need to set hdev HCI_UNREGISTER flag > in hci_alloc_dev_priv(). > > Signed-off-by: Wei Yongjun <weiyongjun1@xxxxxxxxxx> > > diff --git a/net/bluetooth/hci_core.c b/net/bluetooth/hci_core.c > index 8a47a3017d61..42410f568e90 100644 > --- a/net/bluetooth/hci_core.c > +++ b/net/bluetooth/hci_core.c > @@ -3876,6 +3876,11 @@ struct hci_dev *hci_alloc_dev_priv(int sizeof_priv) > INIT_DELAYED_WORK(&hdev->cmd_timer, hci_cmd_timeout); > INIT_DELAYED_WORK(&hdev->ncmd_timer, hci_ncmd_timeout); > > + /* We need to set HCI_UNREGISTER flag to correctly release > + * the device in hci_free_dev() > + */ > + hci_dev_set_flag(hdev, HCI_UNREGISTER); > + I can see the point in the bug report, but I don’t see that the fix is correct. Can you prove that this fix is correct when hci_register_dev is actually called. Regards Marcel
