bisecting fixing commit since cbfa1702aaf69b2311ea1b35e04f113c48368c67 building syzkaller on 6bfdbe8950b22b1c832478bd397754f3108df040 testing commit cbfa1702aaf69b2311ea1b35e04f113c48368c67 compiler: gcc version 8.4.1 20210217 (GCC) kernel signature: c431f85b811df62064a65421a9064c299d727cf14bd8f5cae72f17be2c820aea all runs: crashed: KASAN: use-after-free Read in hci_chan_del testing current HEAD f96eb53cbd76415edfba99c2cfa88567a885a428 testing commit f96eb53cbd76415edfba99c2cfa88567a885a428 compiler: gcc version 8.4.1 20210217 (GCC) kernel signature: 106178575e4fe8a1341d2b8ad23839f99cfa3cedf7356430c1a5dc69db0ad88b all runs: crashed: unregister_netdevice: waiting for DEV to become free revisions tested: 2, total time: 30m38.907939775s (build: 23m19.578586458s, test: 6m28.32178756s) the crash still happens on HEAD commit msg: Linux 4.14.246 crash: unregister_netdevice: waiting for DEV to become free Bluetooth: hci0 command 0x0409 tx timeout Bluetooth: hci3 command 0x0409 tx timeout Bluetooth: hci4 command 0x0409 tx timeout Bluetooth: hci1 command 0x0409 tx timeout Bluetooth: hci5 command 0x0409 tx timeout unregister_netdevice: waiting for ip6gre0 to become free. Usage count = -1 Bluetooth: hci2 command 0x041b tx timeout Bluetooth: hci5 command 0x041b tx timeout Bluetooth: hci1 command 0x041b tx timeout Bluetooth: hci4 command 0x041b tx timeout Bluetooth: hci3 command 0x041b tx timeout Bluetooth: hci0 command 0x041b tx timeout Bluetooth: hci0 command 0x040f tx timeout Bluetooth: hci5 command 0x040f tx timeout Bluetooth: hci3 command 0x040f tx timeout Bluetooth: hci4 command 0x040f tx timeout Bluetooth: hci1 command 0x040f tx timeout Bluetooth: hci2 command 0x040f tx timeout Bluetooth: hci5 command 0x0419 tx timeout Bluetooth: hci2 command 0x0419 tx timeout Bluetooth: hci1 command 0x0419 tx timeout Bluetooth: hci4 command 0x0419 tx timeout Bluetooth: hci3 command 0x0419 tx timeout Bluetooth: hci0 command 0x0419 tx timeout