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BUG: KASAN: slab-out-of-bounds in __list_del_entry_valid_or_report+0x92/0x190 lib/list_debug.c:62
Read of size 8 at addr ffff888058866760 by task syz.5.1391/9928

CPU: 1 UID: 0 PID: 9928 Comm: syz.5.1391 Not tainted syzkaller #0 PREEMPT_{RT,(full)} 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
Call Trace:
 <TASK>
 dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:378 [inline]
 print_report+0xca/0x240 mm/kasan/report.c:482
 kasan_report+0x118/0x150 mm/kasan/report.c:595
 __list_del_entry_valid_or_report+0x92/0x190 lib/list_debug.c:62
 __list_del_entry_valid include/linux/list.h:124 [inline]
 __list_del_entry include/linux/list.h:215 [inline]
 list_del_init include/linux/list.h:287 [inline]
 bt_accept_unlink+0x39/0x240 net/bluetooth/af_bluetooth.c:259
 l2cap_sock_teardown_cb+0x17e/0x460 net/bluetooth/l2cap_sock.c:1613
 l2cap_chan_del+0xb5/0x5e0 net/bluetooth/l2cap_core.c:655
 l2cap_conn_del+0x388/0x680 net/bluetooth/l2cap_core.c:1787
 hci_disconn_cfm include/net/bluetooth/hci_core.h:2097 [inline]
 hci_conn_hash_flush+0x10a/0x230 net/bluetooth/hci_conn.c:2575
 hci_dev_close_sync+0xaef/0x1330 net/bluetooth/hci_sync.c:5294
 hci_dev_do_close net/bluetooth/hci_core.c:501 [inline]
 hci_unregister_dev+0x21a/0x510 net/bluetooth/hci_core.c:2715
 vhci_release+0x83/0xe0 drivers/bluetooth/hci_vhci.c:665
 __fput+0x45b/0xa80 fs/file_table.c:468
 task_work_run+0x1d4/0x260 kernel/task_work.c:227
 exit_task_work include/linux/task_work.h:40 [inline]
 do_exit+0x6b5/0x2300 kernel/exit.c:961
 do_group_exit+0x21c/0x2d0 kernel/exit.c:1102
 get_signal+0x125e/0x1310 kernel/signal.c:3034
 arch_do_signal_or_restart+0x9a/0x750 arch/x86/kernel/signal.c:337
 exit_to_user_mode_loop+0x75/0x110 kernel/entry/common.c:40
 exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline]
 syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline]
 do_syscall_64+0x2bd/0x3b0 arch/x86/entry/syscall_64.c:100
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f67888514a5
Code: Unable to access opcode bytes at 0x7f678885147b.
RSP: 002b:00007f6786a7df80 EFLAGS: 00000293 ORIG_RAX: 00000000000000e6
RAX: fffffffffffffdfc RBX: 00007f6788a45fa0 RCX: 00007f67888514a5
RDX: 00007f6786a7dfc0 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007f67888a1e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000000
R13: 00007f6788a46038 R14: 00007f6788a45fa0 R15: 00007fff0e80a938
 </TASK>

Allocated by task 1365:
 kasan_save_stack mm/kasan/common.c:47 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:68
 poison_kmalloc_redzone mm/kasan/common.c:388 [inline]
 __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:405
 kasan_kmalloc include/linux/kasan.h:260 [inline]
 __do_kmalloc_node mm/slub.c:4365 [inline]
 __kmalloc_noprof+0x1ef/0x430 mm/slub.c:4377
 kmalloc_noprof include/linux/slab.h:909 [inline]
 kzalloc_noprof include/linux/slab.h:1039 [inline]
 neigh_alloc net/core/neighbour.c:522 [inline]
 ___neigh_create+0x722/0x2360 net/core/neighbour.c:656
 ip6_finish_output2+0xb51/0x1720 net/ipv6/ip6_output.c:132
 NF_HOOK include/linux/netfilter.h:318 [inline]
 ndisc_send_skb+0xb54/0x1440 net/ipv6/ndisc.c:512
 ndisc_send_ns+0xcb/0x150 net/ipv6/ndisc.c:670
 addrconf_dad_work+0xb7b/0x15a0 net/ipv6/addrconf.c:4282
 process_one_work kernel/workqueue.c:3236 [inline]
 process_scheduled_works+0xade/0x17b0 kernel/workqueue.c:3319
 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3400
 kthread+0x711/0x8a0 kernel/kthread.c:463
 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

The buggy address belongs to the object at ffff888058866000
 which belongs to the cache kmalloc-2k of size 2048
The buggy address is located 784 bytes to the right of
 allocated 1104-byte region [ffff888058866000, ffff888058866450)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x58860
head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0x80000000000040(head|node=0|zone=1)
page_type: f5(slab)
raw: 0080000000000040 ffff888019842000 ffffea0000a48200 dead000000000002
raw: 0000000000000000 0000000000080008 00000000f5000000 0000000000000000
head: 0080000000000040 ffff888019842000 ffffea0000a48200 dead000000000002
head: 0000000000000000 0000000000080008 00000000f5000000 0000000000000000
head: 0080000000000003 ffffea0001621801 00000000ffffffff 00000000ffffffff
head: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000008
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 3, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 5836, tgid 5836 (syz-executor), ts 88314312539, free_ts 0
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x240/0x2a0 mm/page_alloc.c:1851
 prep_new_page mm/page_alloc.c:1859 [inline]
 get_page_from_freelist+0x2119/0x21b0 mm/page_alloc.c:3858
 __alloc_frozen_pages_noprof+0x181/0x370 mm/page_alloc.c:5148
 alloc_pages_mpol+0xd1/0x380 mm/mempolicy.c:2416
 alloc_slab_page mm/slub.c:2487 [inline]
 allocate_slab+0x8a/0x370 mm/slub.c:2655
 new_slab mm/slub.c:2709 [inline]
 ___slab_alloc+0x8d1/0xdd0 mm/slub.c:3891
 __slab_alloc mm/slub.c:3981 [inline]
 __slab_alloc_node mm/slub.c:4056 [inline]
 slab_alloc_node mm/slub.c:4217 [inline]
 __kmalloc_cache_noprof+0xe6/0x320 mm/slub.c:4391
 kmalloc_noprof include/linux/slab.h:905 [inline]
 rtnl_newlink+0xed/0x1c70 net/core/rtnetlink.c:3957
 rtnetlink_rcv_msg+0x7cc/0xb70 net/core/rtnetlink.c:6946
 netlink_rcv_skb+0x205/0x470 net/netlink/af_netlink.c:2552
 netlink_unicast_kernel net/netlink/af_netlink.c:1320 [inline]
 netlink_unicast+0x843/0xa10 net/netlink/af_netlink.c:1346
 netlink_sendmsg+0x805/0xb30 net/netlink/af_netlink.c:1896
 sock_sendmsg_nosec net/socket.c:714 [inline]
 __sock_sendmsg+0x219/0x270 net/socket.c:729
 __sys_sendto+0x3c7/0x520 net/socket.c:2228
 __do_sys_sendto net/socket.c:2235 [inline]
 __se_sys_sendto net/socket.c:2231 [inline]
 __x64_sys_sendto+0xde/0x100 net/socket.c:2231
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
page_owner free stack trace missing

Memory state around the buggy address:
 ffff888058866600: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff888058866680: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff888058866700: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
                                                       ^
 ffff888058866780: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff888058866800: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
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