> From: Luiz Augusto von Dentz <luiz.von.dentz@xxxxxxxxx> > > device_add shall not be called multiple times as stated in its > documentation: > > 'Do not call this routine or device_register() more than once for > any device structure' > > Syzkaller reports a bug as follows [1]: > ------------[ cut here ]------------ > kernel BUG at lib/list_debug.c:33! > invalid opcode: 0000 [#1] PREEMPT SMP KASAN > [...] > Call Trace: > <TASK> > __list_add include/linux/list.h:69 [inline] > list_add_tail include/linux/list.h:102 [inline] > kobj_kset_join lib/kobject.c:164 [inline] > kobject_add_internal+0x18f/0x8f0 lib/kobject.c:214 > kobject_add_varg lib/kobject.c:358 [inline] > kobject_add+0x150/0x1c0 lib/kobject.c:410 > device_add+0x368/0x1e90 drivers/base/core.c:3452 > hci_conn_add_sysfs+0x9b/0x1b0 net/bluetooth/hci_sysfs.c:53 > hci_le_cis_estabilished_evt+0x57c/0xae0 net/bluetooth/hci_event.c:6799 > hci_le_meta_evt+0x2b8/0x510 net/bluetooth/hci_event.c:7110 > hci_event_func net/bluetooth/hci_event.c:7440 [inline] > hci_event_packet+0x63d/0xfd0 net/bluetooth/hci_event.c:7495 > hci_rx_work+0xae7/0x1230 net/bluetooth/hci_core.c:4007 > process_one_work+0x991/0x1610 kernel/workqueue.c:2289 > worker_thread+0x665/0x1080 kernel/workqueue.c:2436 > kthread+0x2e4/0x3a0 kernel/kthread.c:376 > ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306 > </TASK> > > Link: https://syzkaller.appspot.com/bug?id=da3246e2d33afdb92d66bc166a0934c5b146404a I tried the reproducer from syzkaller, and it didn't trigger any issues. And I also tryied multiple HCI_LE_CIS_Estabilished events, still normal. Test-by: Hawkins Jiawei <yin31149@xxxxxxxxx> > Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@xxxxxxxxx> > --- > net/bluetooth/hci_sysfs.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/net/bluetooth/hci_sysfs.c b/net/bluetooth/hci_sysfs.c > index 4e3e0451b08c..08542dfc2dc5 100644 > --- a/net/bluetooth/hci_sysfs.c > +++ b/net/bluetooth/hci_sysfs.c > @@ -48,6 +48,9 @@ void hci_conn_add_sysfs(struct hci_conn *conn) > > BT_DBG("conn %p", conn); > > + if (device_is_registered(&conn->dev)) > + return; > + > dev_set_name(&conn->dev, "%s:%d", hdev->name, conn->handle); > > if (device_add(&conn->dev) < 0) { > -- > 2.37.3
