bisecting fixing commit since 7d7d1c0ab3eb7c8d8f63a126535018007823b207
building syzkaller on bc5434be1a615eca6d901c20b026712bd9697fd4
testing commit 7d7d1c0ab3eb7c8d8f63a126535018007823b207 with gcc (GCC) 8.4.1 20210217
kernel signature: 7d2f2bbdac34af5039bc7f930bf0922e33696ca00f5391cb1cff213e8460c9df
run #0: crashed: KASAN: use-after-free Read in nbd_put
run #1: crashed: KASAN: use-after-free Read in nbd_put
run #2: crashed: KASAN: use-after-free Read in nbd_put
run #3: crashed: KASAN: use-after-free Read in nbd_put
run #4: crashed: KASAN: use-after-free Read in nbd_put
run #5: crashed: KASAN: use-after-free Read in nbd_put
run #6: crashed: KASAN: use-after-free Read in nbd_put
run #7: crashed: KASAN: use-after-free Read in nbd_put
run #8: crashed: KASAN: use-after-free Read in nbd_put
run #9: crashed: KASAN: use-after-free Write in ex_handler_refcount
run #10: crashed: KASAN: use-after-free Read in nbd_put
run #11: crashed: KASAN: use-after-free Read in nbd_put
run #12: crashed: KASAN: use-after-free Read in nbd_put
run #13: crashed: KASAN: use-after-free Read in nbd_put
run #14: crashed: KASAN: use-after-free Read in nbd_put
run #15: crashed: KASAN: use-after-free Read in nbd_put
run #16: crashed: KASAN: use-after-free Write in ex_handler_refcount
run #17: crashed: KASAN: use-after-free Read in nbd_put
run #18: crashed: KASAN: use-after-free Read in nbd_put
run #19: crashed: KASAN: use-after-free Read in nbd_put
testing current HEAD 4e68c9b0763ff55eaa69d6e519f07515f1c9037b
testing commit 4e68c9b0763ff55eaa69d6e519f07515f1c9037b with gcc (GCC) 8.4.1 20210217
kernel signature: 7ef62e904a357fc372e498aa1122b9d8492c55e0c9cb39218630157c783ecb0d
all runs: crashed: unregister_netdevice: waiting for DEV to become free
revisions tested: 2, total time: 22m14.25663278s (build: 15m8.52554522s, test: 6m41.583139672s)
the crash still happens on HEAD
commit msg: Linux 4.14.239
crash: unregister_netdevice: waiting for DEV to become free
Bluetooth: hci3 command 0x0409 tx timeout
Bluetooth: hci0 command 0x0409 tx timeout
Bluetooth: hci2 command 0x0409 tx timeout
Bluetooth: hci5 command 0x0409 tx timeout
Bluetooth: hci4 command 0x0409 tx timeout
unregister_netdevice: waiting for ip6gre0 to become free. Usage count = -1
Bluetooth: hci0 command 0x041b tx timeout
Bluetooth: hci3 command 0x041b tx timeout
Bluetooth: hci1 command 0x041b tx timeout
Bluetooth: hci4 command 0x041b tx timeout
Bluetooth: hci5 command 0x041b tx timeout
Bluetooth: hci2 command 0x041b tx timeout
Bluetooth: hci1 command 0x040f tx timeout
Bluetooth: hci3 command 0x040f tx timeout
Bluetooth: hci0 command 0x040f tx timeout
Bluetooth: hci2 command 0x040f tx timeout
Bluetooth: hci5 command 0x040f tx timeout
Bluetooth: hci4 command 0x040f tx timeout
Bluetooth: hci0 command 0x0419 tx timeout
Bluetooth: hci3 command 0x0419 tx timeout
Bluetooth: hci1 command 0x0419 tx timeout
Bluetooth: hci4 command 0x0419 tx timeout
Bluetooth: hci5 command 0x0419 tx timeout
Bluetooth: hci2 command 0x0419 tx timeout