bisecting fixing commit since 6fbc7275c7a9ba97877050335f290341a1fd8dbf
building syzkaller on 907bf74686129436f81aa40336ee89f7cc01b0b4
testing commit 6fbc7275c7a9ba97877050335f290341a1fd8dbf with gcc (GCC) 8.1.0
kernel signature: 8e74f00a30e9a0261d26c6c95d5bbdd3fee1825c801594432b39cb2710384282
run #0: crashed: WARNING in kernfs_get
run #1: crashed: WARNING in kernfs_get
run #2: crashed: WARNING: refcount bug in hci_register_dev
run #3: crashed: WARNING: refcount bug in hci_register_dev
run #4: crashed: WARNING in kernfs_put
run #5: crashed: WARNING: refcount bug in hci_register_dev
run #6: crashed: general protection fault in kernfs_add_one
run #7: crashed: WARNING in kernfs_get
run #8: crashed: WARNING in kernfs_get
run #9: crashed: WARNING in kernfs_get
testing current HEAD fb33c6510d5595144d585aa194d377cf74d31911
testing commit fb33c6510d5595144d585aa194d377cf74d31911 with gcc (GCC) 8.1.0
kernel signature: 85e3ab97725dad17577844af2da645c63b58ee53617d3479fb9e3acadf8819f2
all runs: crashed: BUG: MAX_LOCKDEP_CHAIN_HLOCKS too low!
revisions tested: 2, total time: 20m38.484154971s (build: 11m41.887376796s, test: 8m22.759700975s)
the crash still happens on HEAD
commit msg: Linux 5.6-rc6
crash: BUG: MAX_LOCKDEP_CHAIN_HLOCKS too low!
BUG: MAX_LOCKDEP_CHAIN_HLOCKS too low!
turning off the locking correctness validator.
CPU: 0 PID: 1538 Comm: kworker/u5:0 Not tainted 5.6.0-rc6-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: hci1 wq_barrier_func
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x12d/0x187 lib/dump_stack.c:118
 add_chain_cache kernel/locking/lockdep.c:2840 [inline]
 lookup_chain_cache_add kernel/locking/lockdep.c:2914 [inline]
 validate_chain kernel/locking/lockdep.c:2935 [inline]
 __lock_acquire.cold.65+0x18/0x385 kernel/locking/lockdep.c:3954
 lock_acquire+0x194/0x410 kernel/locking/lockdep.c:4484
 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
 _raw_spin_lock_irqsave+0x99/0xd0 kernel/locking/spinlock.c:159
 try_to_wake_up+0xa6/0x1930 kernel/sched/core.c:2547
 default_wake_function+0x30/0x50 kernel/sched/core.c:4348
 __wake_up_common+0x149/0x5f0 kernel/sched/wait.c:93
 __wake_up_locked+0x11/0x20 kernel/sched/wait.c:151
 complete+0x57/0x80 kernel/sched/completion.c:36
 wq_barrier_func+0xd/0x10 kernel/workqueue.c:2620
 process_one_work+0x88b/0x1680 kernel/workqueue.c:2266
 process_scheduled_works kernel/workqueue.c:2328 [inline]
 worker_thread+0x5ad/0xb60 kernel/workqueue.c:2414
 kthread+0x331/0x3f0 kernel/kthread.c:255
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352