bisecting fixing commit since 6fbc7275c7a9ba97877050335f290341a1fd8dbf building syzkaller on 907bf74686129436f81aa40336ee89f7cc01b0b4 testing commit 6fbc7275c7a9ba97877050335f290341a1fd8dbf with gcc (GCC) 8.1.0 kernel signature: 054df4114147ae654b61838d15926ea3731369aa847faf43cbf487c85c355602 run #0: crashed: WARNING in kernfs_get run #1: crashed: WARNING in kernfs_get run #2: crashed: general protection fault in kernfs_add_one run #3: crashed: WARNING in kernfs_get run #4: crashed: WARNING: refcount bug in hci_register_dev run #5: crashed: WARNING in kernfs_get run #6: crashed: WARNING in kernfs_get run #7: crashed: WARNING in kernfs_get run #8: crashed: WARNING in rfkill_unregister run #9: crashed: BUG: MAX_LOCKDEP_CHAIN_HLOCKS too low! testing current HEAD fdfa3a6778b194974df77b384cc71eb2e503639a testing commit fdfa3a6778b194974df77b384cc71eb2e503639a with gcc (GCC) 8.1.0 kernel signature: b92dfe3749e1d45b23554427b3286b3695c7be9b222613aaa7dc357804504f5b all runs: crashed: BUG: MAX_LOCKDEP_CHAIN_HLOCKS too low! revisions tested: 2, total time: 22m2.770428716s (build: 12m31.455518239s, test: 9m1.551289209s) the crash still happens on HEAD commit msg: Merge tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi crash: BUG: MAX_LOCKDEP_CHAIN_HLOCKS too low! BUG: MAX_LOCKDEP_CHAIN_HLOCKS too low! turning off the locking correctness validator. CPU: 0 PID: 8170 Comm: kworker/u5:2 Not tainted 5.5.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: hci3 hci_power_on 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 process_one_work+0x7fa/0x1680 kernel/workqueue.c:2239 worker_thread+0x85/0xb60 kernel/workqueue.c:2410 kthread+0x331/0x3f0 kernel/kthread.c:255 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352