bisecting fixing commit since 7d7d1c0ab3eb7c8d8f63a126535018007823b207 building syzkaller on 06c27ff56b460864b5195bc0668d1d582df3cbf8 testing commit 7d7d1c0ab3eb7c8d8f63a126535018007823b207 compiler: gcc version 8.4.1 20210217 (GCC) kernel signature: 66e63930f41f34e2547ff2f65a7b6bb6db5eae8a061e1f386bf2708ccc3c932f run #0: crashed: KASAN: use-after-free Read in ip_check_mc_rcu run #1: crashed: KASAN: use-after-free Read in ip_check_mc_rcu run #2: crashed: KASAN: use-after-free Read in ip_check_mc_rcu run #3: crashed: KASAN: use-after-free Read in ip_check_mc_rcu run #4: crashed: KASAN: use-after-free Read in ip_check_mc_rcu run #5: crashed: KASAN: use-after-free Read in ip_check_mc_rcu run #6: crashed: KASAN: use-after-free Read in ip_check_mc_rcu run #7: crashed: KASAN: use-after-free Read in ip_check_mc_rcu run #8: crashed: KASAN: use-after-free Read in ip_check_mc_rcu run #9: crashed: KASAN: use-after-free Read in ip_check_mc_rcu run #10: crashed: KASAN: use-after-free Read in ip_check_mc_rcu run #11: crashed: KASAN: use-after-free Read in ip_check_mc_rcu run #12: OK run #13: OK run #14: OK run #15: OK run #16: OK run #17: OK run #18: OK run #19: OK testing current HEAD cd529693461026636f76d0395a42cb2439bbd368 testing commit cd529693461026636f76d0395a42cb2439bbd368 compiler: gcc version 8.4.1 20210217 (GCC) kernel signature: c77159879c649352fa8ee74ee23535436a7a9320878584b55cfab0eb075e9c65 all runs: crashed: unregister_netdevice: waiting for DEV to become free revisions tested: 2, total time: 32m12.231706473s (build: 16m57.966900397s, test: 14m50.373742771s) the crash still happens on HEAD commit msg: Linux 4.14.253 crash: unregister_netdevice: waiting for DEV to become free Bluetooth: hci1 command 0x0409 tx timeout Bluetooth: hci0 command 0x0409 tx timeout Bluetooth: hci4 command 0x0409 tx timeout Bluetooth: hci5 command 0x0409 tx timeout Bluetooth: hci3 command 0x0409 tx timeout unregister_netdevice: waiting for ip6gre0 to become free. Usage count = -1 Bluetooth: hci2 command 0x0409 tx timeout Bluetooth: hci0 command 0x041b tx timeout Bluetooth: hci1 command 0x041b tx timeout Bluetooth: hci2 command 0x041b tx timeout Bluetooth: hci3 command 0x041b tx timeout Bluetooth: hci5 command 0x041b tx timeout Bluetooth: hci4 command 0x041b tx timeout Bluetooth: hci1 command 0x040f tx timeout Bluetooth: hci0 command 0x040f tx timeout Bluetooth: hci4 command 0x040f tx timeout Bluetooth: hci5 command 0x040f tx timeout Bluetooth: hci3 command 0x040f tx timeout Bluetooth: hci2 command 0x040f tx timeout Bluetooth: hci0 command 0x0419 tx timeout Bluetooth: hci1 command 0x0419 tx timeout Bluetooth: hci2 command 0x0419 tx timeout Bluetooth: hci3 command 0x0419 tx timeout Bluetooth: hci5 command 0x0419 tx timeout Bluetooth: hci4 command 0x0419 tx timeout