BUG: MAX_LOCKDEP_CHAIN_HLOCKS too low!
turning off the locking correctness validator.
CPU: 1 PID: 23206 Comm: syz-executor.2 Not tainted 5.6.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x188/0x20d 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+0x263/0x288 kernel/locking/lockdep.c:3954
 lock_acquire+0x197/0x420 kernel/locking/lockdep.c:4484
 __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline]
 _raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:151
 rq_lock kernel/sched/sched.h:1215 [inline]
 __schedule+0x232/0x1f90 kernel/sched/core.c:4028
 preempt_schedule_common+0x4a/0xc0 kernel/sched/core.c:4235
 ___preempt_schedule+0x16/0x18 arch/x86/entry/thunk_64.S:50
 __mutex_lock_common kernel/locking/mutex.c:1095 [inline]
 __mutex_lock+0xf73/0x13c0 kernel/locking/mutex.c:1103
 dropmon_net_event+0x308/0x470 net/core/drop_monitor.c:1516
 notifier_call_chain+0xc0/0x230 kernel/notifier.c:83
 call_netdevice_notifiers_info net/core/dev.c:1948 [inline]
 call_netdevice_notifiers_info+0xb5/0x130 net/core/dev.c:1933
 call_netdevice_notifiers_extack net/core/dev.c:1960 [inline]
 call_netdevice_notifiers net/core/dev.c:1974 [inline]
 register_netdevice+0xce6/0x1020 net/core/dev.c:9421
 ppp_unit_register drivers/net/ppp/ppp_generic.c:1075 [inline]
 ppp_dev_configure+0x968/0xcd0 drivers/net/ppp/ppp_generic.c:1131
 ppp_create_interface drivers/net/ppp/ppp_generic.c:3139 [inline]
 ppp_unattached_ioctl drivers/net/ppp/ppp_generic.c:927 [inline]
 ppp_ioctl+0x190f/0x25f0 drivers/net/ppp/ppp_generic.c:626
 vfs_ioctl fs/ioctl.c:47 [inline]
 ksys_ioctl+0x11a/0x180 fs/ioctl.c:763
 __do_sys_ioctl fs/ioctl.c:772 [inline]
 __se_sys_ioctl fs/ioctl.c:770 [inline]
 __x64_sys_ioctl+0x6f/0xb0 fs/ioctl.c:770
 do_syscall_64+0xf6/0x7d0 arch/x86/entry/common.c:294
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x45c849
Code: ad b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 7b b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007faea3646c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007faea36476d4 RCX: 000000000045c849
RDX: 0000000020000680 RSI: 00000000c004743e RDI: 0000000000000003
RBP: 000000000076c0e0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 0000000000000416 R14: 00000000004d36c0 R15: 000000000076c0ec