==================================================================
BUG: KASAN: slab-use-after-free in __list_del_entry_valid_or_report+0x92/0x190 lib/list_debug.c:62
Read of size 8 at addr ffff8880533f4578 by task syz-executor/9599

CPU: 1 UID: 0 PID: 9599 Comm: syz-executor Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:378 [inline]
 print_report+0xba/0x230 mm/kasan/report.c:482
 kasan_report+0x117/0x150 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:132 [inline]
 __list_del_entry include/linux/list.h:223 [inline]
 list_del_init include/linux/list.h:295 [inline]
 bt_accept_unlink+0x39/0x260 net/bluetooth/af_bluetooth.c:259
 l2cap_sock_teardown_cb+0x17e/0x490 net/bluetooth/l2cap_sock.c:1640
 l2cap_chan_del+0xb5/0x610 net/bluetooth/l2cap_core.c:656
 l2cap_conn_del+0x33d/0x570 net/bluetooth/l2cap_core.c:1802
 hci_disconn_cfm include/net/bluetooth/hci_core.h:2154 [inline]
 hci_conn_hash_flush+0x10d/0x260 net/bluetooth/hci_conn.c:2650
 hci_dev_close_sync+0x821/0x10e0 net/bluetooth/hci_sync.c:5368
 hci_dev_do_close net/bluetooth/hci_core.c:502 [inline]
 hci_unregister_dev+0x21a/0x5a0 net/bluetooth/hci_core.c:2716
 vhci_release+0x152/0x1a0 drivers/bluetooth/hci_vhci.c:690
 __fput+0x44f/0xa60 fs/file_table.c:510
 task_work_run+0x1d9/0x270 kernel/task_work.c:233
 exit_task_work include/linux/task_work.h:40 [inline]
 do_exit+0x70f/0x23c0 kernel/exit.c:976
 do_group_exit+0x21b/0x2d0 kernel/exit.c:1118
 __do_sys_exit_group kernel/exit.c:1129 [inline]
 __se_sys_exit_group kernel/exit.c:1127 [inline]
 __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1127
 x64_sys_call+0x221a/0x2240 arch/x86/include/generated/asm/syscalls_64.h:232
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fa037b9c819
Code: Unable to access opcode bytes at 0x7fa037b9c7ef.
RSP: 002b:00007ffce3b71dc8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 00007fa037c3206d RCX: 00007fa037b9c819
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000001
RBP: 0000000000000075 R08: 0000000000000000 R09: 00007fa037c32048
R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffce3b73080
R13: 00007fa037c32048 R14: 0000000000118657 R15: 00007ffce3b75240
 </TASK>

Allocated by task 17916:
 kasan_save_stack mm/kasan/common.c:57 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
 poison_kmalloc_redzone mm/kasan/common.c:398 [inline]
 __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:415
 kasan_kmalloc include/linux/kasan.h:263 [inline]
 __do_kmalloc_node mm/slub.c:5260 [inline]
 __kmalloc_node_track_caller_noprof+0x4db/0x7b0 mm/slub.c:5368
 kmalloc_reserve net/core/skbuff.c:635 [inline]
 __alloc_skb+0x2c1/0x7d0 net/core/skbuff.c:713
 alloc_skb include/linux/skbuff.h:1383 [inline]
 nlmsg_new include/net/netlink.h:1055 [inline]
 inet6_ifinfo_notify+0x70/0x120 net/ipv6/addrconf.c:6183
 addrconf_notify+0xca0/0x1050 net/ipv6/addrconf.c:3764
 notifier_call_chain+0x1ad/0x3d0 kernel/notifier.c:85
 call_netdevice_notifiers_extack net/core/dev.c:2287 [inline]
 call_netdevice_notifiers net/core/dev.c:2301 [inline]
 __dev_notify_flags+0x1a9/0x310 net/core/dev.c:9820
 rtnl_configure_link net/core/rtnetlink.c:3628 [inline]
 rtnl_newlink_create+0x657/0xb70 net/core/rtnetlink.c:3872
 __rtnl_newlink net/core/rtnetlink.c:3993 [inline]
 rtnl_newlink+0x166a/0x1bb0 net/core/rtnetlink.c:4108
 rtnetlink_rcv_msg+0x7d5/0xbe0 net/core/rtnetlink.c:6994
 netlink_rcv_skb+0x232/0x4b0 net/netlink/af_netlink.c:2550
 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline]
 netlink_unicast+0x80f/0x9b0 net/netlink/af_netlink.c:1344
 netlink_sendmsg+0x813/0xb40 net/netlink/af_netlink.c:1894
 sock_sendmsg_nosec net/socket.c:792 [inline]
 __sock_sendmsg net/socket.c:807 [inline]
 ____sys_sendmsg+0x972/0x9f0 net/socket.c:2657
 ___sys_sendmsg+0x2a5/0x360 net/socket.c:2711
 __sys_sendmsg net/socket.c:2743 [inline]
 __do_sys_sendmsg net/socket.c:2748 [inline]
 __se_sys_sendmsg net/socket.c:2746 [inline]
 __x64_sys_sendmsg+0x1bd/0x2a0 net/socket.c:2746
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Freed by task 17916:
 kasan_save_stack mm/kasan/common.c:57 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
 kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:584
 poison_slab_object mm/kasan/common.c:253 [inline]
 __kasan_slab_free+0x5c/0x80 mm/kasan/common.c:285
 kasan_slab_free include/linux/kasan.h:235 [inline]
 slab_free_hook mm/slub.c:2685 [inline]
 slab_free mm/slub.c:6165 [inline]
 kfree+0x1c1/0x620 mm/slub.c:6483
 skb_kfree_head net/core/skbuff.c:1086 [inline]
 skb_free_head net/core/skbuff.c:1098 [inline]
 skb_release_data+0x6c3/0x8f0 net/core/skbuff.c:1125
 skb_release_all net/core/skbuff.c:1200 [inline]
 __kfree_skb+0x5d/0x210 net/core/skbuff.c:1214
 netlink_broadcast_filtered+0xee4/0x1020 net/netlink/af_netlink.c:1535
 nlmsg_multicast_filtered include/net/netlink.h:1165 [inline]
 nlmsg_multicast include/net/netlink.h:1184 [inline]
 nlmsg_notify+0xf0/0x1a0 net/netlink/af_netlink.c:2593
 addrconf_notify+0xca0/0x1050 net/ipv6/addrconf.c:3764
 notifier_call_chain+0x1ad/0x3d0 kernel/notifier.c:85
 call_netdevice_notifiers_extack net/core/dev.c:2287 [inline]
 call_netdevice_notifiers net/core/dev.c:2301 [inline]
 __dev_notify_flags+0x1a9/0x310 net/core/dev.c:9820
 rtnl_configure_link net/core/rtnetlink.c:3628 [inline]
 rtnl_newlink_create+0x657/0xb70 net/core/rtnetlink.c:3872
 __rtnl_newlink net/core/rtnetlink.c:3993 [inline]
 rtnl_newlink+0x166a/0x1bb0 net/core/rtnetlink.c:4108
 rtnetlink_rcv_msg+0x7d5/0xbe0 net/core/rtnetlink.c:6994
 netlink_rcv_skb+0x232/0x4b0 net/netlink/af_netlink.c:2550
 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline]
 netlink_unicast+0x80f/0x9b0 net/netlink/af_netlink.c:1344
 netlink_sendmsg+0x813/0xb40 net/netlink/af_netlink.c:1894
 sock_sendmsg_nosec net/socket.c:792 [inline]
 __sock_sendmsg net/socket.c:807 [inline]
 ____sys_sendmsg+0x972/0x9f0 net/socket.c:2657
 ___sys_sendmsg+0x2a5/0x360 net/socket.c:2711
 __sys_sendmsg net/socket.c:2743 [inline]
 __do_sys_sendmsg net/socket.c:2748 [inline]
 __se_sys_sendmsg net/socket.c:2746 [inline]
 __x64_sys_sendmsg+0x1bd/0x2a0 net/socket.c:2746
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

The buggy address belongs to the object at ffff8880533f4000
 which belongs to the cache kmalloc-2k of size 2048
The buggy address is located 1400 bytes inside of
 freed 2048-byte region [ffff8880533f4000, ffff8880533f4800)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff8880533f3000 pfn:0x533f0
head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0xfff00000000240(workingset|head|node=0|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 00fff00000000240 ffff88813fea6000 ffffea0001026410 ffffea0001323c10
raw: ffff8880533f3000 0000000800080006 00000000f5000000 0000000000000000
head: 00fff00000000240 ffff88813fea6000 ffffea0001026410 ffffea0001323c10
head: ffff8880533f3000 0000000800080006 00000000f5000000 0000000000000000
head: 00fff00000000003 ffffea00014cfc01 00000000ffffffff 00000000ffffffff
head: ffffffffffffffff 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 5821, tgid 5821 (syz-executor), ts 80339957895, free_ts 20472197874
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x231/0x280 mm/page_alloc.c:1889
 prep_new_page mm/page_alloc.c:1897 [inline]
 get_page_from_freelist+0x24dc/0x2580 mm/page_alloc.c:3962
 __alloc_frozen_pages_noprof+0x18d/0x380 mm/page_alloc.c:5250
 alloc_slab_page mm/slub.c:3292 [inline]
 allocate_slab+0x77/0x660 mm/slub.c:3481
 new_slab mm/slub.c:3539 [inline]
 refill_objects+0x331/0x3c0 mm/slub.c:7175
 refill_sheaf mm/slub.c:2812 [inline]
 __pcs_replace_empty_main+0x2e6/0x730 mm/slub.c:4615
 alloc_from_pcs mm/slub.c:4717 [inline]
 slab_alloc_node mm/slub.c:4851 [inline]
 __do_kmalloc_node mm/slub.c:5259 [inline]
 __kmalloc_noprof+0x474/0x760 mm/slub.c:5272
 kmalloc_noprof include/linux/slab.h:954 [inline]
 sk_prot_alloc+0xe7/0x210 net/core/sock.c:2245
 sk_alloc+0x3a/0x390 net/core/sock.c:2301
 __netlink_create+0x65/0x260 net/netlink/af_netlink.c:626
 netlink_create+0x3ca/0x590 net/netlink/af_netlink.c:684
 __sock_create+0x4b2/0x9d0 net/socket.c:1670
 sock_create net/socket.c:1728 [inline]
 __sys_socket_create net/socket.c:1765 [inline]
 __sys_socket+0xd6/0x1b0 net/socket.c:1812
 __do_sys_socket net/socket.c:1826 [inline]
 __se_sys_socket net/socket.c:1824 [inline]
 __x64_sys_socket+0x7a/0x90 net/socket.c:1824
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
page last free pid 1 tgid 1 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 __free_pages_prepare mm/page_alloc.c:1433 [inline]
 __free_frozen_pages+0xc2b/0xdb0 mm/page_alloc.c:2978
 __free_pages mm/page_alloc.c:5369 [inline]
 free_contig_range+0xbb/0x170 mm/page_alloc.c:7374
 destroy_args+0x4e5/0x570 mm/debug_vm_pgtable.c:993
 debug_vm_pgtable+0x3f8/0x410 mm/debug_vm_pgtable.c:1368
 do_one_initcall+0x250/0x870 init/main.c:1392
 do_initcall_level+0x104/0x190 init/main.c:1454
 do_initcalls+0x59/0xa0 init/main.c:1470
 kernel_init_freeable+0x2a6/0x3e0 init/main.c:1703
 kernel_init+0x1d/0x1d0 init/main.c:1593
 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

Memory state around the buggy address:
 ffff8880533f4400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8880533f4480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff8880533f4500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                                                ^
 ffff8880533f4580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8880533f4600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================