Ping. Let me add the bluetooth mailing list as well to see if anyone knows. regards, dan carpenter On Mon, Jul 03, 2023 at 04:21:32PM +0300, Dan Carpenter wrote: > Hello Jing Cai, > > The patch 872f8c253cb9: "Bluetooth: btusb: mediatek: add MediaTek > devcoredump support" from Jun 29, 2023, leads to the following Smatch > static checker warning: > > drivers/bluetooth/btmtk.c:409 btmtk_process_coredump() > error: double free of 'skb' > > drivers/bluetooth/btmtk.c > 381 if (err < 0) > 382 break; > 383 data->cd_info.cnt = 0; > 384 > 385 /* It is supposed coredump can be done within 5 seconds */ > 386 schedule_delayed_work(&hdev->dump.dump_timeout, > 387 msecs_to_jiffies(5000)); > 388 fallthrough; > 389 case HCI_DEVCOREDUMP_ACTIVE: > 390 default: > 391 err = hci_devcd_append(hdev, skb); > > hci_devcd_append() free skb on error > > 392 if (err < 0) > 393 break; > 394 data->cd_info.cnt++; > 395 > 396 /* Mediatek coredump data would be more than MTK_COREDUMP_NUM */ > 397 if (data->cd_info.cnt > MTK_COREDUMP_NUM && > 398 skb->len > sizeof(MTK_COREDUMP_END) && > 399 !memcmp((char *)&skb->data[skb->len - sizeof(MTK_COREDUMP_END)], > 400 MTK_COREDUMP_END, sizeof(MTK_COREDUMP_END) - 1)) { > 401 bt_dev_info(hdev, "Mediatek coredump end"); > 402 hci_devcd_complete(hdev); > 403 } > 404 > 405 break; > 406 } > 407 > 408 if (err < 0) > 409 kfree_skb(skb); > > double free > > 410 > 411 return err; > 412 } > > regards, > dan carpenter >