bisecting fixing commit since 0cc244011f40280b78fc344d5c2aac5a0c659f77
building syzkaller on 6a81331a1d4c744da9204d02ec88d558f7eea9c9
testing commit 0cc244011f40280b78fc344d5c2aac5a0c659f77 with gcc (GCC) 8.4.1 20210217
kernel signature: 06251ad78feb897f1d13e81699fa61a69753c502544062e3e9f56074e8e86363
all runs: crashed: WARNING: ODEBUG bug in pppol2tp_release
testing current HEAD 7d7d1c0ab3eb7c8d8f63a126535018007823b207
testing commit 7d7d1c0ab3eb7c8d8f63a126535018007823b207 with gcc (GCC) 8.4.1 20210217
kernel signature: 6cd38793d11eb99e87f67d5637d8702eb0db9766f410ea25200fbd4dd051fb08
all runs: crashed: WARNING: ODEBUG bug in pppol2tp_release
revisions tested: 2, total time: 27m57.076826306s (build: 19m46.502849705s, test: 7m39.196022261s)
the crash still happens on HEAD
commit msg: Linux 4.14.232
crash: WARNING: ODEBUG bug in pppol2tp_release
Bluetooth: hci4 command 0x0419 tx timeout
ODEBUG: activate active (active state 1) object type: rcu_head hint:           (null)
------------[ cut here ]------------
WARNING: CPU: 0 PID: 21981 at lib/debugobjects.c:290 debug_print_object.cold.8+0xa7/0xdb lib/debugobjects.c:287
Kernel panic - not syncing: panic_on_warn set ...

CPU: 0 PID: 21981 Comm: syz-executor.5 Not tainted 4.14.232-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:17 [inline]
 dump_stack+0x14b/0x1e7 lib/dump_stack.c:58
 panic+0x1b0/0x358 kernel/panic.c:183
 __warn.cold.7+0x25/0x25 kernel/panic.c:547
 report_bug+0x1a1/0x200 lib/bug.c:186
 fixup_bug arch/x86/kernel/traps.c:177 [inline]
 fixup_bug arch/x86/kernel/traps.c:172 [inline]
 do_error_trap+0x1bd/0x310 arch/x86/kernel/traps.c:295
 do_invalid_op+0x1b/0x20 arch/x86/kernel/traps.c:314
 invalid_op+0x1b/0x40 arch/x86/entry/entry_64.S:964
RIP: 0010:debug_print_object.cold.8+0xa7/0xdb lib/debugobjects.c:287
RSP: 0018:ffff888097067958 EFLAGS: 00010082
RAX: 0000000000000055 RBX: 0000000000000003 RCX: 0000000000000000
RDX: 0000000000000055 RSI: ffffffff878b9220 RDI: ffffed1012e0cf22
RBP: ffff888097067980 R08: 0000000000000000 R09: 0000000000000000
R10: fffffbfff15ec6f0 R11: dffffc0000000000 R12: ffffffff878ae360
R13: 0000000000000000 R14: 0000000000000001 R15: ffffffff8b107708
 debug_object_activate+0x364/0x4b0 lib/debugobjects.c:446
 debug_rcu_head_queue kernel/rcu/rcu.h:152 [inline]
 __call_rcu.constprop.48+0x35/0x7d0 kernel/rcu/tree.c:3050
 call_rcu+0x12/0x20 kernel/rcu/tree_plugin.h:730
 pppol2tp_release+0x272/0x3a0 net/l2tp/l2tp_ppp.c:515
 __sock_release+0xc2/0x2a0 net/socket.c:602
 sock_close+0x10/0x20 net/socket.c:1139
 __fput+0x232/0x740 fs/file_table.c:210
 ____fput+0x9/0x10 fs/file_table.c:244
 task_work_run+0xe5/0x170 kernel/task_work.c:113
 get_signal+0x1447/0x1a90 kernel/signal.c:2234
 do_signal+0x7f/0x18b0 arch/x86/kernel/signal.c:792
 exit_to_usermode_loop+0x11e/0x190 arch/x86/entry/common.c:160
 prepare_exit_to_usermode arch/x86/entry/common.c:199 [inline]
 syscall_return_slowpath arch/x86/entry/common.c:270 [inline]
 do_syscall_64+0x416/0x5b0 arch/x86/entry/common.c:297
 entry_SYSCALL_64_after_hwframe+0x46/0xbb
RIP: 0033:0x466459
RSP: 002b:00007f97b52ff188 EFLAGS: 00000246 ORIG_RAX: 000000000000002a
RAX: 0000000000000000 RBX: 000000000056bf60 RCX: 0000000000466459
RDX: 0000000000000032 RSI: 0000000020000140 RDI: 0000000000000005
RBP: 00000000004bf9fb R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056bf60
R13: 00007ffff886e0cf R14: 00007f97b52ff300 R15: 0000000000022000

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