BUG: spinlock bad magic on CPU#0, kworker/0:5/9650
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BUG: KASAN: slab-out-of-bounds in task_pid_nr include/linux/sched.h:1408 [inline]
BUG: KASAN: slab-out-of-bounds in spin_dump kernel/locking/spinlock_debug.c:65 [inline]
BUG: KASAN: slab-out-of-bounds in spin_bug.cold+0x95/0x9e kernel/locking/spinlock_debug.c:75
Read of size 4 at addr ffff8880614b37c0 by task kworker/0:5/9650

CPU: 0 PID: 9650 Comm: kworker/0:5 Not tainted 5.11.0-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:79 [inline]
 dump_stack+0x141/0x1d7 lib/dump_stack.c:120
 print_address_description.constprop.0.cold+0x5b/0x2f8 mm/kasan/report.c:230
 __kasan_report mm/kasan/report.c:397 [inline]
 kasan_report.cold+0x79/0xd5 mm/kasan/report.c:414
 task_pid_nr include/linux/sched.h:1408 [inline]
 spin_dump kernel/locking/spinlock_debug.c:65 [inline]
 spin_bug.cold+0x95/0x9e kernel/locking/spinlock_debug.c:75
 debug_spin_lock_before kernel/locking/spinlock_debug.c:83 [inline]
 do_raw_spin_lock+0x216/0x2b0 kernel/locking/spinlock_debug.c:112
 spin_lock_bh include/linux/spinlock.h:359 [inline]
 lock_sock_nested+0x40/0x120 net/core/sock.c:3063
 l2cap_sock_teardown_cb+0xa1/0x660 net/bluetooth/l2cap_sock.c:1520
 l2cap_chan_del+0xbc/0xa80 net/bluetooth/l2cap_core.c:618
 l2cap_chan_close+0x1bc/0xaf0 net/bluetooth/l2cap_core.c:823
 l2cap_chan_timeout+0x17e/0x2f0 net/bluetooth/l2cap_core.c:436
 process_one_work+0x98d/0x1600 kernel/workqueue.c:2275
 worker_thread+0x64c/0x1120 kernel/workqueue.c:2421
 kthread+0x3b1/0x4a0 kernel/kthread.c:292
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294

Allocated by task 15610:
 kasan_save_stack+0x1b/0x40 mm/kasan/common.c:38
 kasan_set_track mm/kasan/common.c:46 [inline]
 set_alloc_info mm/kasan/common.c:400 [inline]
 ____kasan_kmalloc.constprop.0+0x82/0xa0 mm/kasan/common.c:428
 kmalloc include/linux/slab.h:559 [inline]
 kzalloc include/linux/slab.h:684 [inline]
 __register_sysctl_table+0x112/0x1090 fs/proc/proc_sysctl.c:1317
 __addrconf_sysctl_register+0x1db/0x3d0 net/ipv6/addrconf.c:6942
 addrconf_sysctl_register net/ipv6/addrconf.c:6989 [inline]
 addrconf_sysctl_register+0x139/0x1d0 net/ipv6/addrconf.c:6978
 ipv6_add_dev+0x92a/0x10e0 net/ipv6/addrconf.c:445
 addrconf_notify+0x8d7/0x23e0 net/ipv6/addrconf.c:3491
 notifier_call_chain+0xb5/0x200 kernel/notifier.c:83
 call_netdevice_notifiers_info+0xb5/0x130 net/core/dev.c:2063
 call_netdevice_notifiers_extack net/core/dev.c:2075 [inline]
 call_netdevice_notifiers net/core/dev.c:2089 [inline]
 register_netdevice+0x1030/0x14a0 net/core/dev.c:10209
 veth_newlink+0x401/0xa00 drivers/net/veth.c:1385
 __rtnl_newlink+0x1059/0x1710 net/core/rtnetlink.c:3443
 rtnl_newlink+0x64/0xa0 net/core/rtnetlink.c:3491
 rtnetlink_rcv_msg+0x44e/0xad0 net/core/rtnetlink.c:5553
 netlink_rcv_skb+0x153/0x420 net/netlink/af_netlink.c:2502
 netlink_unicast_kernel net/netlink/af_netlink.c:1312 [inline]
 netlink_unicast+0x533/0x7d0 net/netlink/af_netlink.c:1338
 netlink_sendmsg+0x856/0xd90 net/netlink/af_netlink.c:1927
 sock_sendmsg_nosec net/socket.c:654 [inline]
 sock_sendmsg+0xcf/0x120 net/socket.c:674
 ____sys_sendmsg+0x6e8/0x810 net/socket.c:2350
 ___sys_sendmsg+0xf3/0x170 net/socket.c:2404
 __sys_sendmsg+0xe5/0x1b0 net/socket.c:2437
 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xae

Last potentially related work creation:
 kasan_save_stack+0x1b/0x40 mm/kasan/common.c:38
 kasan_record_aux_stack+0xc5/0xf0 mm/kasan/generic.c:344
 __call_rcu kernel/rcu/tree.c:3039 [inline]
 call_rcu+0xb1/0x740 kernel/rcu/tree.c:3114
 netlink_release+0xd48/0x1cf0 net/netlink/af_netlink.c:810
 __sock_release+0xcd/0x280 net/socket.c:599
 sock_close+0x18/0x20 net/socket.c:1258
 __fput+0x288/0x920 fs/file_table.c:280
 task_work_run+0xdd/0x1a0 kernel/task_work.c:140
 tracehook_notify_resume include/linux/tracehook.h:189 [inline]
 exit_to_user_mode_loop kernel/entry/common.c:174 [inline]
 exit_to_user_mode_prepare+0x249/0x250 kernel/entry/common.c:208
 __syscall_exit_to_user_mode_work kernel/entry/common.c:290 [inline]
 syscall_exit_to_user_mode+0x19/0x50 kernel/entry/common.c:301
 entry_SYSCALL_64_after_hwframe+0x44/0xae

Second to last potentially related work creation:
 kasan_save_stack+0x1b/0x40 mm/kasan/common.c:38
 kasan_record_aux_stack+0xc5/0xf0 mm/kasan/generic.c:344
 kvfree_call_rcu+0x10e/0x7d0 kernel/rcu/tree.c:3577
 drop_sysctl_table+0x3c0/0x4e0 fs/proc/proc_sysctl.c:1646
 unregister_sysctl_table fs/proc/proc_sysctl.c:1684 [inline]
 unregister_sysctl_table+0xc2/0x190 fs/proc/proc_sysctl.c:1659
 __addrconf_sysctl_unregister net/ipv6/addrconf.c:6971 [inline]
 addrconf_sysctl_unregister+0xee/0x1c0 net/ipv6/addrconf.c:6999
 addrconf_ifdown.isra.0+0xfa8/0x15b0 net/ipv6/addrconf.c:3849
 addrconf_notify+0x55c/0x23e0 net/ipv6/addrconf.c:3631
 notifier_call_chain+0xb5/0x200 kernel/notifier.c:83
 call_netdevice_notifiers_info+0xb5/0x130 net/core/dev.c:2063
 call_netdevice_notifiers_extack net/core/dev.c:2075 [inline]
 call_netdevice_notifiers net/core/dev.c:2089 [inline]
 unregister_netdevice_many+0x942/0x1760 net/core/dev.c:10905
 ip6_tnl_exit_batch_net+0x477/0x6a0 net/ipv6/ip6_tunnel.c:2300
 ops_exit_list+0x10d/0x160 net/core/net_namespace.c:178
 cleanup_net+0x4ea/0xb10 net/core/net_namespace.c:595
 process_one_work+0x98d/0x1600 kernel/workqueue.c:2275
 worker_thread+0x64c/0x1120 kernel/workqueue.c:2421
 kthread+0x3b1/0x4a0 kernel/kthread.c:292
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294

The buggy address belongs to the object at ffff8880614b3000
 which belongs to the cache kmalloc-2k of size 2048
The buggy address is located 1984 bytes inside of
 2048-byte region [ffff8880614b3000, ffff8880614b3800)
The buggy address belongs to the page:
page:000000009d8f2ebe refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x614b0
head:000000009d8f2ebe order:3 compound_mapcount:0 compound_pincount:0
flags: 0xfff00000010200(slab|head)
raw: 00fff00000010200 dead000000000100 dead000000000122 ffff888010c42000
raw: 0000000000000000 0000000000080008 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8880614b3680: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 fc fc
 ffff8880614b3700: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff8880614b3780: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
                                           ^
 ffff8880614b3800: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff8880614b3880: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
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