overlayfs: unrecognized mount option "lowerdir" or missing value
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BUG: KASAN: use-after-free in __lock_acquire+0x2c57/0x3f20 kernel/locking/lockdep.c:3369
Read of size 8 at addr ffff8880a9686ae0 by task kworker/1:2/3547

CPU: 1 PID: 3547 Comm: kworker/1:2 Not tainted 4.14.215-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: events l2cap_chan_timeout
Call Trace:
 __dump_stack lib/dump_stack.c:17 [inline]
 dump_stack+0x1b2/0x283 lib/dump_stack.c:58
 print_address_description.cold+0x54/0x1d3 mm/kasan/report.c:252
 kasan_report_error.cold+0x8a/0x194 mm/kasan/report.c:351
 kasan_report mm/kasan/report.c:409 [inline]
 __asan_report_load8_noabort+0x68/0x70 mm/kasan/report.c:430
 __lock_acquire+0x2c57/0x3f20 kernel/locking/lockdep.c:3369
 lock_acquire+0x170/0x3f0 kernel/locking/lockdep.c:3998
 __raw_spin_lock_bh include/linux/spinlock_api_smp.h:135 [inline]
 _raw_spin_lock_bh+0x2f/0x40 kernel/locking/spinlock.c:176
 spin_lock_bh include/linux/spinlock.h:322 [inline]
 lock_sock_nested+0x39/0x100 net/core/sock.c:2788
 l2cap_sock_teardown_cb+0x93/0x650 net/bluetooth/l2cap_sock.c:1341
 l2cap_chan_del+0xaf/0x950 net/bluetooth/l2cap_core.c:599
 l2cap_chan_close+0x103/0x870 net/bluetooth/l2cap_core.c:757
 l2cap_chan_timeout+0x143/0x2a0 net/bluetooth/l2cap_core.c:430
 process_one_work+0x793/0x14a0 kernel/workqueue.c:2116
 worker_thread+0x5cc/0xff0 kernel/workqueue.c:2250
 kthread+0x30d/0x420 kernel/kthread.c:232
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404

Allocated by task 21990:
 save_stack mm/kasan/kasan.c:447 [inline]
 set_track mm/kasan/kasan.c:459 [inline]
 kasan_kmalloc+0xeb/0x160 mm/kasan/kasan.c:551
 __do_kmalloc mm/slab.c:3720 [inline]
 __kmalloc+0x15a/0x400 mm/slab.c:3729
 kmalloc include/linux/slab.h:493 [inline]
 kzalloc include/linux/slab.h:661 [inline]
 __register_sysctl_table+0xfd/0xf90 fs/proc/proc_sysctl.c:1304
 __devinet_sysctl_register+0x13d/0x250 net/ipv4/devinet.c:2314
 devinet_sysctl_register+0x134/0x1f0 net/ipv4/devinet.c:2354
 inetdev_init+0x202/0x410 net/ipv4/devinet.c:262
 inetdev_event+0x8b4/0x1098 net/ipv4/devinet.c:1462
 notifier_call_chain+0x108/0x1a0 kernel/notifier.c:93
 call_netdevice_notifiers_info net/core/dev.c:1667 [inline]
 call_netdevice_notifiers net/core/dev.c:1683 [inline]
 register_netdevice+0xb98/0xe40 net/core/dev.c:7691
 register_netdev+0x17/0x30 net/core/dev.c:7805
 sit_init_net+0x2cf/0x8d0 net/ipv6/sit.c:1848
 ops_init+0xaa/0x3e0 net/core/net_namespace.c:118
 setup_net+0x22f/0x530 net/core/net_namespace.c:295
 copy_net_ns+0x19b/0x440 net/core/net_namespace.c:419
 create_new_namespaces+0x375/0x720 kernel/nsproxy.c:107
 copy_namespaces+0x27b/0x310 kernel/nsproxy.c:165
 copy_process.part.0+0x25f8/0x71c0 kernel/fork.c:1793
 copy_process kernel/fork.c:1605 [inline]
 _do_fork+0x184/0xc80 kernel/fork.c:2091
 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x46/0xbb

Freed by task 21986:
 save_stack mm/kasan/kasan.c:447 [inline]
 set_track mm/kasan/kasan.c:459 [inline]
 kasan_slab_free+0xc3/0x1a0 mm/kasan/kasan.c:524
 __cache_free mm/slab.c:3496 [inline]
 kfree+0xc9/0x250 mm/slab.c:3815
 __rcu_reclaim kernel/rcu/rcu.h:190 [inline]
 rcu_do_batch kernel/rcu/tree.c:2699 [inline]
 invoke_rcu_callbacks kernel/rcu/tree.c:2962 [inline]
 __rcu_process_callbacks kernel/rcu/tree.c:2929 [inline]
 rcu_process_callbacks+0x88b/0x1180 kernel/rcu/tree.c:2946
 __do_softirq+0x254/0xa1d kernel/softirq.c:288

The buggy address belongs to the object at ffff8880a9686a40
 which belongs to the cache kmalloc-2048 of size 2048
The buggy address is located 160 bytes inside of
 2048-byte region [ffff8880a9686a40, ffff8880a9687240)
The buggy address belongs to the page:
page:ffffea0002a5a180 count:1 mapcount:0 mapping:ffff8880a96861c0 index:0xffff8880a96861c0 compound_mapcount: 0
flags: 0xfff00000008100(slab|head)
raw: 00fff00000008100 ffff8880a96861c0 ffff8880a96861c0 0000000100000001
raw: ffffea00024cbba0 ffffea0002bd0720 ffff88813fe80c40 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8880a9686980: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
 ffff8880a9686a00: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb
>ffff8880a9686a80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                                       ^
 ffff8880a9686b00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8880a9686b80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
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