bisecting fixing commit since 14b58326976de6ef3998eefec1dd7f8b38b97a75
building syzkaller on 28ac5c9e93a44c3eb145195ffb55591be58ef510
testing commit 14b58326976de6ef3998eefec1dd7f8b38b97a75 with gcc (GCC) 8.4.1 20210217
kernel signature: ac562f9f98fc595103e79186c889464df7afc151b770b7c4f5d9a7a7fc75c82b
run #0: crashed: BUG: corrupted list in l2cap_chan_put
run #1: crashed: BUG: corrupted list in l2cap_chan_put
run #2: crashed: BUG: corrupted list in l2cap_chan_put
run #3: crashed: BUG: corrupted list in l2cap_chan_put
run #4: crashed: KASAN: use-after-free Read in l2cap_sock_shutdown
run #5: crashed: KASAN: use-after-free Read in l2cap_sock_shutdown
run #6: crashed: KASAN: use-after-free Read in l2cap_sock_shutdown
run #7: crashed: KASAN: use-after-free Read in l2cap_sock_shutdown
run #8: crashed: KASAN: use-after-free Read in l2cap_sock_shutdown
run #9: crashed: KASAN: use-after-free Read in l2cap_sock_shutdown
run #10: crashed: KASAN: use-after-free Read in l2cap_sock_shutdown
run #11: crashed: KASAN: use-after-free Read in l2cap_sock_shutdown
run #12: crashed: BUG: corrupted list in l2cap_chan_put
run #13: crashed: KASAN: use-after-free Read in l2cap_chan_put
run #14: crashed: BUG: corrupted list in l2cap_chan_put
run #15: crashed: KASAN: use-after-free Read in l2cap_sock_shutdown
run #16: crashed: KASAN: use-after-free Read in l2cap_sock_shutdown
run #17: crashed: KASAN: use-after-free Read in l2cap_sock_shutdown
run #18: crashed: KASAN: use-after-free Read in l2cap_sock_shutdown
run #19: crashed: BUG: corrupted list in l2cap_chan_put
testing current HEAD cfb41ef9deb1e6572ac218ddfcec9567e5d1c101
testing commit cfb41ef9deb1e6572ac218ddfcec9567e5d1c101 with gcc (GCC) 8.4.1 20210217
kernel signature: 71e5815505b4e96def3e00a336711d7ce400ea10488e4fa985892e3d23053d49
all runs: crashed: unregister_netdevice: waiting for DEV to become free
revisions tested: 2, total time: 30m16.301963388s (build: 17m0.416693048s, test: 12m46.838156337s)
the crash still happens on HEAD
commit msg: Linux 4.14.237
crash: unregister_netdevice: waiting for DEV to become free
unregister_netdevice: waiting for ip6gre0 to become free. Usage count = -1