==================================================================
BUG: KASAN: slab-use-after-free in __list_del_entry_valid_or_report+0x1d4/0x200 lib/list_debug.c:62
Read of size 8 at addr ffff88807d682558 by task syz.4.1097/13438

CPU: 1 UID: 0 PID: 13438 Comm: syz.4.1097 Not tainted 6.15.0-rc7-syzkaller-00002-gb36ddb9210e6 #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:408 [inline]
 print_report+0xc3/0x670 mm/kasan/report.c:521
 kasan_report+0xe0/0x110 mm/kasan/report.c:634
 __list_del_entry_valid_or_report+0x1d4/0x200 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+0x34/0x2e0 net/bluetooth/af_bluetooth.c:256
 l2cap_sock_teardown_cb+0x1a3/0x3c0 net/bluetooth/l2cap_sock.c:1613
 l2cap_chan_del+0xbd/0x8f0 net/bluetooth/l2cap_core.c:655
 l2cap_conn_del+0x37a/0x730 net/bluetooth/l2cap_core.c:1786
 l2cap_disconn_cfm net/bluetooth/l2cap_core.c:7300 [inline]
 l2cap_disconn_cfm+0x96/0xd0 net/bluetooth/l2cap_core.c:7293
 hci_disconn_cfm include/net/bluetooth/hci_core.h:2068 [inline]
 hci_conn_hash_flush+0x10e/0x260 net/bluetooth/hci_conn.c:2534
 hci_dev_close_sync+0x602/0x11d0 net/bluetooth/hci_sync.c:5225
 hci_dev_do_close+0x2e/0x90 net/bluetooth/hci_core.c:483
 hci_unregister_dev+0x213/0x620 net/bluetooth/hci_core.c:2678
 vhci_release+0x79/0xf0 drivers/bluetooth/hci_vhci.c:665
 __fput+0x402/0xb70 fs/file_table.c:465
 task_work_run+0x150/0x240 kernel/task_work.c:227
 exit_task_work include/linux/task_work.h:40 [inline]
 do_exit+0xafb/0x2c30 kernel/exit.c:953
 do_group_exit+0xd3/0x2a0 kernel/exit.c:1102
 get_signal+0x2673/0x26d0 kernel/signal.c:3034
 arch_do_signal_or_restart+0x8f/0x7d0 arch/x86/kernel/signal.c:337
 exit_to_user_mode_loop kernel/entry/common.c:111 [inline]
 exit_to_user_mode_prepare include/linux/entry-common.h:329 [inline]
 __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
 syscall_exit_to_user_mode+0x150/0x2a0 kernel/entry/common.c:218
 do_syscall_64+0xda/0x260 arch/x86/entry/syscall_64.c:100
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f8fb21907fc
Code: Unable to access opcode bytes at 0x7f8fb21907d2.
RSP: 002b:00007f8fb305bec0 EFLAGS: 00000293 ORIG_RAX: 000000000000002c
RAX: 0000000000000020 RBX: 00007f8fb305bfc0 RCX: 00007f8fb21907fc
RDX: 0000000000000020 RSI: 00007f8fb305c010 RDI: 0000000000000007
RBP: 0000000000000000 R08: 00007f8fb305bf14 R09: 000000000000000c
R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000007
R13: 00007f8fb305bf68 R14: 00007f8fb305c010 R15: 0000000000000000
 </TASK>

Allocated by task 13083:
 kasan_save_stack+0x33/0x60 mm/kasan/common.c:47
 kasan_save_track+0x14/0x30 mm/kasan/common.c:68
 poison_kmalloc_redzone mm/kasan/common.c:377 [inline]
 __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:394
 kasan_kmalloc include/linux/kasan.h:260 [inline]
 __do_kmalloc_node mm/slub.c:4327 [inline]
 __kmalloc_noprof+0x223/0x510 mm/slub.c:4339
 kmalloc_noprof include/linux/slab.h:909 [inline]
 sk_prot_alloc+0x1a8/0x2a0 net/core/sock.c:2198
 sk_alloc+0x36/0xc20 net/core/sock.c:2254
 bt_sock_alloc+0x3b/0x3a0 net/bluetooth/af_bluetooth.c:148
 l2cap_sock_alloc.constprop.0+0x33/0x1d0 net/bluetooth/l2cap_sock.c:1891
 l2cap_sock_create+0x123/0x1f0 net/bluetooth/l2cap_sock.c:1933
 bt_sock_create+0x185/0x350 net/bluetooth/af_bluetooth.c:132
 __sock_create+0x338/0x8d0 net/socket.c:1541
 sock_create net/socket.c:1599 [inline]
 __sys_socket_create net/socket.c:1636 [inline]
 __sys_socket+0x14d/0x260 net/socket.c:1683
 __do_sys_socket net/socket.c:1697 [inline]
 __se_sys_socket net/socket.c:1695 [inline]
 __x64_sys_socket+0x72/0xb0 net/socket.c:1695
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xcd/0x260 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Freed by task 13083:
 kasan_save_stack+0x33/0x60 mm/kasan/common.c:47
 kasan_save_track+0x14/0x30 mm/kasan/common.c:68
 kasan_save_free_info+0x3b/0x60 mm/kasan/generic.c:576
 poison_slab_object mm/kasan/common.c:247 [inline]
 __kasan_slab_free+0x51/0x70 mm/kasan/common.c:264
 kasan_slab_free include/linux/kasan.h:233 [inline]
 slab_free_hook mm/slub.c:2380 [inline]
 slab_free mm/slub.c:4642 [inline]
 kfree+0x2b6/0x4d0 mm/slub.c:4841
 sk_prot_free net/core/sock.c:2237 [inline]
 __sk_destruct+0x740/0x980 net/core/sock.c:2332
 sk_destruct+0xc2/0xf0 net/core/sock.c:2360
 __sk_free+0xf4/0x3e0 net/core/sock.c:2371
 sk_free+0x6a/0x90 net/core/sock.c:2382
 sock_put include/net/sock.h:1944 [inline]
 l2cap_sock_kill net/bluetooth/l2cap_sock.c:1265 [inline]
 l2cap_sock_kill+0x171/0x2d0 net/bluetooth/l2cap_sock.c:1250
 l2cap_sock_release+0x189/0x210 net/bluetooth/l2cap_sock.c:1435
 __sock_release+0xb3/0x270 net/socket.c:647
 sock_close+0x1c/0x30 net/socket.c:1391
 __fput+0x402/0xb70 fs/file_table.c:465
 task_work_run+0x150/0x240 kernel/task_work.c:227
 get_signal+0x1d1/0x26d0 kernel/signal.c:2807
 arch_do_signal_or_restart+0x8f/0x7d0 arch/x86/kernel/signal.c:337
 exit_to_user_mode_loop kernel/entry/common.c:111 [inline]
 exit_to_user_mode_prepare include/linux/entry-common.h:329 [inline]
 __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
 syscall_exit_to_user_mode+0x150/0x2a0 kernel/entry/common.c:218
 do_syscall_64+0xda/0x260 arch/x86/entry/syscall_64.c:100
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

The buggy address belongs to the object at ffff88807d682000
 which belongs to the cache kmalloc-2k of size 2048
The buggy address is located 1368 bytes inside of
 freed 2048-byte region [ffff88807d682000, ffff88807d682800)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff88807d682000 pfn:0x7d680
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 ffff88801b442000 ffffea0001644610 ffffea0001546010
raw: ffff88807d682000 0000000000080002 00000000f5000000 0000000000000000
head: 00fff00000000240 ffff88801b442000 ffffea0001644610 ffffea0001546010
head: ffff88807d682000 0000000000080002 00000000f5000000 0000000000000000
head: 00fff00000000003 ffffea0001f5a001 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 3503, tgid 3503 (kworker/u8:10), ts 124288038087, free_ts 124217847342
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x181/0x1b0 mm/page_alloc.c:1714
 prep_new_page mm/page_alloc.c:1722 [inline]
 get_page_from_freelist+0x135c/0x3920 mm/page_alloc.c:3684
 __alloc_frozen_pages_noprof+0x263/0x23a0 mm/page_alloc.c:4966
 alloc_pages_mpol+0x1fb/0x550 mm/mempolicy.c:2301
 alloc_slab_page mm/slub.c:2450 [inline]
 allocate_slab mm/slub.c:2618 [inline]
 new_slab+0x244/0x340 mm/slub.c:2672
 ___slab_alloc+0xd9c/0x1940 mm/slub.c:3858
 __slab_alloc.constprop.0+0x56/0xb0 mm/slub.c:3948
 __slab_alloc_node mm/slub.c:4023 [inline]
 slab_alloc_node mm/slub.c:4184 [inline]
 __do_kmalloc_node mm/slub.c:4326 [inline]
 __kmalloc_node_track_caller_noprof+0x2ee/0x510 mm/slub.c:4346
 kmalloc_reserve+0xef/0x2c0 net/core/skbuff.c:599
 __alloc_skb+0x166/0x380 net/core/skbuff.c:668
 alloc_skb include/linux/skbuff.h:1340 [inline]
 mld_newpack.isra.0+0x18e/0xa20 net/ipv6/mcast.c:1788
 add_grhead+0x299/0x340 net/ipv6/mcast.c:1899
 add_grec+0x112a/0x1680 net/ipv6/mcast.c:2037
 mld_send_initial_cr.part.0+0xe2/0x260 net/ipv6/mcast.c:2282
 mld_send_initial_cr include/linux/refcount.h:291 [inline]
 ipv6_mc_dad_complete+0x22c/0x2b0 net/ipv6/mcast.c:2293
 addrconf_dad_completed+0xd8a/0x10d0 net/ipv6/addrconf.c:4344
page last free pid 5856 tgid 5856 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1258 [inline]
 __free_frozen_pages+0x69d/0xff0 mm/page_alloc.c:2721
 discard_slab mm/slub.c:2716 [inline]
 __put_partials+0x16d/0x1c0 mm/slub.c:3185
 qlink_free mm/kasan/quarantine.c:163 [inline]
 qlist_free_all+0x4e/0x120 mm/kasan/quarantine.c:179
 kasan_quarantine_reduce+0x195/0x1e0 mm/kasan/quarantine.c:286
 __kasan_slab_alloc+0x69/0x90 mm/kasan/common.c:329
 kasan_slab_alloc include/linux/kasan.h:250 [inline]
 slab_post_alloc_hook mm/slub.c:4147 [inline]
 slab_alloc_node mm/slub.c:4196 [inline]
 __do_kmalloc_node mm/slub.c:4326 [inline]
 __kmalloc_noprof+0x1d4/0x510 mm/slub.c:4339
 kmalloc_noprof include/linux/slab.h:909 [inline]
 kzalloc_noprof include/linux/slab.h:1039 [inline]
 tomoyo_encode2+0x100/0x3e0 security/tomoyo/realpath.c:45
 tomoyo_encode+0x29/0x50 security/tomoyo/realpath.c:80
 tomoyo_realpath_from_path+0x18f/0x6e0 security/tomoyo/realpath.c:283
 tomoyo_get_realpath security/tomoyo/file.c:151 [inline]
 tomoyo_path_perm+0x274/0x460 security/tomoyo/file.c:822
 tomoyo_path_rmdir+0x91/0xe0 security/tomoyo/tomoyo.c:195
 security_path_rmdir+0x145/0x2b0 security/security.c:1949
 do_rmdir+0x27b/0x3c0 fs/namei.c:4506
 __do_sys_rmdir fs/namei.c:4528 [inline]
 __se_sys_rmdir fs/namei.c:4526 [inline]
 __x64_sys_rmdir+0xc5/0x110 fs/namei.c:4526
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xcd/0x260 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Memory state around the buggy address:
 ffff88807d682400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88807d682480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff88807d682500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                                    ^
 ffff88807d682580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88807d682600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================
==================================================================
BUG: KASAN: slab-use-after-free in __list_del_entry_valid_or_report+0x1e1/0x200 lib/list_debug.c:65
Read of size 8 at addr ffff88807d682560 by task syz.4.1097/13438

CPU: 1 UID: 0 PID: 13438 Comm: syz.4.1097 Tainted: G    B               6.15.0-rc7-syzkaller-00002-gb36ddb9210e6 #0 PREEMPT(full) 
Tainted: [B]=BAD_PAGE
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:408 [inline]
 print_report+0xc3/0x670 mm/kasan/report.c:521
 kasan_report+0xe0/0x110 mm/kasan/report.c:634
 __list_del_entry_valid_or_report+0x1e1/0x200 lib/list_debug.c:65
 __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+0x34/0x2e0 net/bluetooth/af_bluetooth.c:256
 l2cap_sock_teardown_cb+0x1a3/0x3c0 net/bluetooth/l2cap_sock.c:1613
 l2cap_chan_del+0xbd/0x8f0 net/bluetooth/l2cap_core.c:655
 l2cap_conn_del+0x37a/0x730 net/bluetooth/l2cap_core.c:1786
 l2cap_disconn_cfm net/bluetooth/l2cap_core.c:7300 [inline]
 l2cap_disconn_cfm+0x96/0xd0 net/bluetooth/l2cap_core.c:7293
 hci_disconn_cfm include/net/bluetooth/hci_core.h:2068 [inline]
 hci_conn_hash_flush+0x10e/0x260 net/bluetooth/hci_conn.c:2534
 hci_dev_close_sync+0x602/0x11d0 net/bluetooth/hci_sync.c:5225
 hci_dev_do_close+0x2e/0x90 net/bluetooth/hci_core.c:483
 hci_unregister_dev+0x213/0x620 net/bluetooth/hci_core.c:2678
 vhci_release+0x79/0xf0 drivers/bluetooth/hci_vhci.c:665
 __fput+0x402/0xb70 fs/file_table.c:465
 task_work_run+0x150/0x240 kernel/task_work.c:227
 exit_task_work include/linux/task_work.h:40 [inline]
 do_exit+0xafb/0x2c30 kernel/exit.c:953
 do_group_exit+0xd3/0x2a0 kernel/exit.c:1102
 get_signal+0x2673/0x26d0 kernel/signal.c:3034
 arch_do_signal_or_restart+0x8f/0x7d0 arch/x86/kernel/signal.c:337
 exit_to_user_mode_loop kernel/entry/common.c:111 [inline]
 exit_to_user_mode_prepare include/linux/entry-common.h:329 [inline]
 __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
 syscall_exit_to_user_mode+0x150/0x2a0 kernel/entry/common.c:218
 do_syscall_64+0xda/0x260 arch/x86/entry/syscall_64.c:100
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f8fb21907fc
Code: Unable to access opcode bytes at 0x7f8fb21907d2.
RSP: 002b:00007f8fb305bec0 EFLAGS: 00000293 ORIG_RAX: 000000000000002c
RAX: 0000000000000020 RBX: 00007f8fb305bfc0 RCX: 00007f8fb21907fc
RDX: 0000000000000020 RSI: 00007f8fb305c010 RDI: 0000000000000007
RBP: 0000000000000000 R08: 00007f8fb305bf14 R09: 000000000000000c
R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000007
R13: 00007f8fb305bf68 R14: 00007f8fb305c010 R15: 0000000000000000
 </TASK>

Allocated by task 13083:
 kasan_save_stack+0x33/0x60 mm/kasan/common.c:47
 kasan_save_track+0x14/0x30 mm/kasan/common.c:68
 poison_kmalloc_redzone mm/kasan/common.c:377 [inline]
 __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:394
 kasan_kmalloc include/linux/kasan.h:260 [inline]
 __do_kmalloc_node mm/slub.c:4327 [inline]
 __kmalloc_noprof+0x223/0x510 mm/slub.c:4339
 kmalloc_noprof include/linux/slab.h:909 [inline]
 sk_prot_alloc+0x1a8/0x2a0 net/core/sock.c:2198
 sk_alloc+0x36/0xc20 net/core/sock.c:2254
 bt_sock_alloc+0x3b/0x3a0 net/bluetooth/af_bluetooth.c:148
 l2cap_sock_alloc.constprop.0+0x33/0x1d0 net/bluetooth/l2cap_sock.c:1891
 l2cap_sock_create+0x123/0x1f0 net/bluetooth/l2cap_sock.c:1933
 bt_sock_create+0x185/0x350 net/bluetooth/af_bluetooth.c:132
 __sock_create+0x338/0x8d0 net/socket.c:1541
 sock_create net/socket.c:1599 [inline]
 __sys_socket_create net/socket.c:1636 [inline]
 __sys_socket+0x14d/0x260 net/socket.c:1683
 __do_sys_socket net/socket.c:1697 [inline]
 __se_sys_socket net/socket.c:1695 [inline]
 __x64_sys_socket+0x72/0xb0 net/socket.c:1695
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xcd/0x260 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Freed by task 13083:
 kasan_save_stack+0x33/0x60 mm/kasan/common.c:47
 kasan_save_track+0x14/0x30 mm/kasan/common.c:68
 kasan_save_free_info+0x3b/0x60 mm/kasan/generic.c:576
 poison_slab_object mm/kasan/common.c:247 [inline]
 __kasan_slab_free+0x51/0x70 mm/kasan/common.c:264
 kasan_slab_free include/linux/kasan.h:233 [inline]
 slab_free_hook mm/slub.c:2380 [inline]
 slab_free mm/slub.c:4642 [inline]
 kfree+0x2b6/0x4d0 mm/slub.c:4841
 sk_prot_free net/core/sock.c:2237 [inline]
 __sk_destruct+0x740/0x980 net/core/sock.c:2332
 sk_destruct+0xc2/0xf0 net/core/sock.c:2360
 __sk_free+0xf4/0x3e0 net/core/sock.c:2371
 sk_free+0x6a/0x90 net/core/sock.c:2382
 sock_put include/net/sock.h:1944 [inline]
 l2cap_sock_kill net/bluetooth/l2cap_sock.c:1265 [inline]
 l2cap_sock_kill+0x171/0x2d0 net/bluetooth/l2cap_sock.c:1250
 l2cap_sock_release+0x189/0x210 net/bluetooth/l2cap_sock.c:1435
 __sock_release+0xb3/0x270 net/socket.c:647
 sock_close+0x1c/0x30 net/socket.c:1391
 __fput+0x402/0xb70 fs/file_table.c:465
 task_work_run+0x150/0x240 kernel/task_work.c:227
 get_signal+0x1d1/0x26d0 kernel/signal.c:2807
 arch_do_signal_or_restart+0x8f/0x7d0 arch/x86/kernel/signal.c:337
 exit_to_user_mode_loop kernel/entry/common.c:111 [inline]
 exit_to_user_mode_prepare include/linux/entry-common.h:329 [inline]
 __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
 syscall_exit_to_user_mode+0x150/0x2a0 kernel/entry/common.c:218
 do_syscall_64+0xda/0x260 arch/x86/entry/syscall_64.c:100
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

The buggy address belongs to the object at ffff88807d682000
 which belongs to the cache kmalloc-2k of size 2048
The buggy address is located 1376 bytes inside of
 freed 2048-byte region [ffff88807d682000, ffff88807d682800)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff88807d682000 pfn:0x7d680
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 ffff88801b442000 ffffea0001644610 ffffea0001546010
raw: ffff88807d682000 0000000000080002 00000000f5000000 0000000000000000
head: 00fff00000000240 ffff88801b442000 ffffea0001644610 ffffea0001546010
head: ffff88807d682000 0000000000080002 00000000f5000000 0000000000000000
head: 00fff00000000003 ffffea0001f5a001 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 3503, tgid 3503 (kworker/u8:10), ts 124288038087, free_ts 124217847342
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x181/0x1b0 mm/page_alloc.c:1714
 prep_new_page mm/page_alloc.c:1722 [inline]
 get_page_from_freelist+0x135c/0x3920 mm/page_alloc.c:3684
 __alloc_frozen_pages_noprof+0x263/0x23a0 mm/page_alloc.c:4966
 alloc_pages_mpol+0x1fb/0x550 mm/mempolicy.c:2301
 alloc_slab_page mm/slub.c:2450 [inline]
 allocate_slab mm/slub.c:2618 [inline]
 new_slab+0x244/0x340 mm/slub.c:2672
 ___slab_alloc+0xd9c/0x1940 mm/slub.c:3858
 __slab_alloc.constprop.0+0x56/0xb0 mm/slub.c:3948
 __slab_alloc_node mm/slub.c:4023 [inline]
 slab_alloc_node mm/slub.c:4184 [inline]
 __do_kmalloc_node mm/slub.c:4326 [inline]
 __kmalloc_node_track_caller_noprof+0x2ee/0x510 mm/slub.c:4346
 kmalloc_reserve+0xef/0x2c0 net/core/skbuff.c:599
 __alloc_skb+0x166/0x380 net/core/skbuff.c:668
 alloc_skb include/linux/skbuff.h:1340 [inline]
 mld_newpack.isra.0+0x18e/0xa20 net/ipv6/mcast.c:1788
 add_grhead+0x299/0x340 net/ipv6/mcast.c:1899
 add_grec+0x112a/0x1680 net/ipv6/mcast.c:2037
 mld_send_initial_cr.part.0+0xe2/0x260 net/ipv6/mcast.c:2282
 mld_send_initial_cr include/linux/refcount.h:291 [inline]
 ipv6_mc_dad_complete+0x22c/0x2b0 net/ipv6/mcast.c:2293
 addrconf_dad_completed+0xd8a/0x10d0 net/ipv6/addrconf.c:4344
page last free pid 5856 tgid 5856 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1258 [inline]
 __free_frozen_pages+0x69d/0xff0 mm/page_alloc.c:2721
 discard_slab mm/slub.c:2716 [inline]
 __put_partials+0x16d/0x1c0 mm/slub.c:3185
 qlink_free mm/kasan/quarantine.c:163 [inline]
 qlist_free_all+0x4e/0x120 mm/kasan/quarantine.c:179
 kasan_quarantine_reduce+0x195/0x1e0 mm/kasan/quarantine.c:286
 __kasan_slab_alloc+0x69/0x90 mm/kasan/common.c:329
 kasan_slab_alloc include/linux/kasan.h:250 [inline]
 slab_post_alloc_hook mm/slub.c:4147 [inline]
 slab_alloc_node mm/slub.c:4196 [inline]
 __do_kmalloc_node mm/slub.c:4326 [inline]
 __kmalloc_noprof+0x1d4/0x510 mm/slub.c:4339
 kmalloc_noprof include/linux/slab.h:909 [inline]
 kzalloc_noprof include/linux/slab.h:1039 [inline]
 tomoyo_encode2+0x100/0x3e0 security/tomoyo/realpath.c:45
 tomoyo_encode+0x29/0x50 security/tomoyo/realpath.c:80
 tomoyo_realpath_from_path+0x18f/0x6e0 security/tomoyo/realpath.c:283
 tomoyo_get_realpath security/tomoyo/file.c:151 [inline]
 tomoyo_path_perm+0x274/0x460 security/tomoyo/file.c:822
 tomoyo_path_rmdir+0x91/0xe0 security/tomoyo/tomoyo.c:195
 security_path_rmdir+0x145/0x2b0 security/security.c:1949
 do_rmdir+0x27b/0x3c0 fs/namei.c:4506
 __do_sys_rmdir fs/namei.c:4528 [inline]
 __se_sys_rmdir fs/namei.c:4526 [inline]
 __x64_sys_rmdir+0xc5/0x110 fs/namei.c:4526
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xcd/0x260 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Memory state around the buggy address:
 ffff88807d682400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88807d682480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff88807d682500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                                       ^
 ffff88807d682580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88807d682600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================
==================================================================
BUG: KASAN: slab-use-after-free in __list_del include/linux/list.h:195 [inline]
BUG: KASAN: slab-use-after-free in __list_del_entry include/linux/list.h:218 [inline]
BUG: KASAN: slab-use-after-free in list_del_init include/linux/list.h:287 [inline]
BUG: KASAN: slab-use-after-free in bt_accept_unlink+0x2c5/0x2e0 net/bluetooth/af_bluetooth.c:256
Write of size 8 at addr ffff88807d682560 by task syz.4.1097/13438

CPU: 0 UID: 0 PID: 13438 Comm: syz.4.1097 Tainted: G    B               6.15.0-rc7-syzkaller-00002-gb36ddb9210e6 #0 PREEMPT(full) 
Tainted: [B]=BAD_PAGE
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:408 [inline]
 print_report+0xc3/0x670 mm/kasan/report.c:521
 kasan_report+0xe0/0x110 mm/kasan/report.c:634
 __list_del include/linux/list.h:195 [inline]
 __list_del_entry include/linux/list.h:218 [inline]
 list_del_init include/linux/list.h:287 [inline]
 bt_accept_unlink+0x2c5/0x2e0 net/bluetooth/af_bluetooth.c:256
 l2cap_sock_teardown_cb+0x1a3/0x3c0 net/bluetooth/l2cap_sock.c:1613
 l2cap_chan_del+0xbd/0x8f0 net/bluetooth/l2cap_core.c:655
 l2cap_conn_del+0x37a/0x730 net/bluetooth/l2cap_core.c:1786
 l2cap_disconn_cfm net/bluetooth/l2cap_core.c:7300 [inline]
 l2cap_disconn_cfm+0x96/0xd0 net/bluetooth/l2cap_core.c:7293
 hci_disconn_cfm include/net/bluetooth/hci_core.h:2068 [inline]
 hci_conn_hash_flush+0x10e/0x260 net/bluetooth/hci_conn.c:2534
 hci_dev_close_sync+0x602/0x11d0 net/bluetooth/hci_sync.c:5225
 hci_dev_do_close+0x2e/0x90 net/bluetooth/hci_core.c:483
 hci_unregister_dev+0x213/0x620 net/bluetooth/hci_core.c:2678
 vhci_release+0x79/0xf0 drivers/bluetooth/hci_vhci.c:665
 __fput+0x402/0xb70 fs/file_table.c:465
 task_work_run+0x150/0x240 kernel/task_work.c:227
 exit_task_work include/linux/task_work.h:40 [inline]
 do_exit+0xafb/0x2c30 kernel/exit.c:953
 do_group_exit+0xd3/0x2a0 kernel/exit.c:1102
 get_signal+0x2673/0x26d0 kernel/signal.c:3034
 arch_do_signal_or_restart+0x8f/0x7d0 arch/x86/kernel/signal.c:337
 exit_to_user_mode_loop kernel/entry/common.c:111 [inline]
 exit_to_user_mode_prepare include/linux/entry-common.h:329 [inline]
 __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
 syscall_exit_to_user_mode+0x150/0x2a0 kernel/entry/common.c:218
 do_syscall_64+0xda/0x260 arch/x86/entry/syscall_64.c:100
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f8fb21907fc
Code: Unable to access opcode bytes at 0x7f8fb21907d2.
RSP: 002b:00007f8fb305bec0 EFLAGS: 00000293 ORIG_RAX: 000000000000002c
RAX: 0000000000000020 RBX: 00007f8fb305bfc0 RCX: 00007f8fb21907fc
RDX: 0000000000000020 RSI: 00007f8fb305c010 RDI: 0000000000000007
RBP: 0000000000000000 R08: 00007f8fb305bf14 R09: 000000000000000c
R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000007
R13: 00007f8fb305bf68 R14: 00007f8fb305c010 R15: 0000000000000000
 </TASK>

Allocated by task 13083:
 kasan_save_stack+0x33/0x60 mm/kasan/common.c:47
 kasan_save_track+0x14/0x30 mm/kasan/common.c:68
 poison_kmalloc_redzone mm/kasan/common.c:377 [inline]
 __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:394
 kasan_kmalloc include/linux/kasan.h:260 [inline]
 __do_kmalloc_node mm/slub.c:4327 [inline]
 __kmalloc_noprof+0x223/0x510 mm/slub.c:4339
 kmalloc_noprof include/linux/slab.h:909 [inline]
 sk_prot_alloc+0x1a8/0x2a0 net/core/sock.c:2198
 sk_alloc+0x36/0xc20 net/core/sock.c:2254
 bt_sock_alloc+0x3b/0x3a0 net/bluetooth/af_bluetooth.c:148
 l2cap_sock_alloc.constprop.0+0x33/0x1d0 net/bluetooth/l2cap_sock.c:1891
 l2cap_sock_create+0x123/0x1f0 net/bluetooth/l2cap_sock.c:1933
 bt_sock_create+0x185/0x350 net/bluetooth/af_bluetooth.c:132
 __sock_create+0x338/0x8d0 net/socket.c:1541
 sock_create net/socket.c:1599 [inline]
 __sys_socket_create net/socket.c:1636 [inline]
 __sys_socket+0x14d/0x260 net/socket.c:1683
 __do_sys_socket net/socket.c:1697 [inline]
 __se_sys_socket net/socket.c:1695 [inline]
 __x64_sys_socket+0x72/0xb0 net/socket.c:1695
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xcd/0x260 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Freed by task 13083:
 kasan_save_stack+0x33/0x60 mm/kasan/common.c:47
 kasan_save_track+0x14/0x30 mm/kasan/common.c:68
 kasan_save_free_info+0x3b/0x60 mm/kasan/generic.c:576
 poison_slab_object mm/kasan/common.c:247 [inline]
 __kasan_slab_free+0x51/0x70 mm/kasan/common.c:264
 kasan_slab_free include/linux/kasan.h:233 [inline]
 slab_free_hook mm/slub.c:2380 [inline]
 slab_free mm/slub.c:4642 [inline]
 kfree+0x2b6/0x4d0 mm/slub.c:4841
 sk_prot_free net/core/sock.c:2237 [inline]
 __sk_destruct+0x740/0x980 net/core/sock.c:2332
 sk_destruct+0xc2/0xf0 net/core/sock.c:2360
 __sk_free+0xf4/0x3e0 net/core/sock.c:2371
 sk_free+0x6a/0x90 net/core/sock.c:2382
 sock_put include/net/sock.h:1944 [inline]
 l2cap_sock_kill net/bluetooth/l2cap_sock.c:1265 [inline]
 l2cap_sock_kill+0x171/0x2d0 net/bluetooth/l2cap_sock.c:1250
 l2cap_sock_release+0x189/0x210 net/bluetooth/l2cap_sock.c:1435
 __sock_release+0xb3/0x270 net/socket.c:647
 sock_close+0x1c/0x30 net/socket.c:1391
 __fput+0x402/0xb70 fs/file_table.c:465
 task_work_run+0x150/0x240 kernel/task_work.c:227
 get_signal+0x1d1/0x26d0 kernel/signal.c:2807
 arch_do_signal_or_restart+0x8f/0x7d0 arch/x86/kernel/signal.c:337
 exit_to_user_mode_loop kernel/entry/common.c:111 [inline]
 exit_to_user_mode_prepare include/linux/entry-common.h:329 [inline]
 __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
 syscall_exit_to_user_mode+0x150/0x2a0 kernel/entry/common.c:218
 do_syscall_64+0xda/0x260 arch/x86/entry/syscall_64.c:100
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

The buggy address belongs to the object at ffff88807d682000
 which belongs to the cache kmalloc-2k of size 2048
The buggy address is located 1376 bytes inside of
 freed 2048-byte region [ffff88807d682000, ffff88807d682800)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff88807d682000 pfn:0x7d680
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 ffff88801b442000 ffffea0001644610 ffffea0001546010
raw: ffff88807d682000 0000000000080002 00000000f5000000 0000000000000000
head: 00fff00000000240 ffff88801b442000 ffffea0001644610 ffffea0001546010
head: ffff88807d682000 0000000000080002 00000000f5000000 0000000000000000
head: 00fff00000000003 ffffea0001f5a001 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 3503, tgid 3503 (kworker/u8:10), ts 124288038087, free_ts 124217847342
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x181/0x1b0 mm/page_alloc.c:1714
 prep_new_page mm/page_alloc.c:1722 [inline]
 get_page_from_freelist+0x135c/0x3920 mm/page_alloc.c:3684
 __alloc_frozen_pages_noprof+0x263/0x23a0 mm/page_alloc.c:4966
 alloc_pages_mpol+0x1fb/0x550 mm/mempolicy.c:2301
 alloc_slab_page mm/slub.c:2450 [inline]
 allocate_slab mm/slub.c:2618 [inline]
 new_slab+0x244/0x340 mm/slub.c:2672
 ___slab_alloc+0xd9c/0x1940 mm/slub.c:3858
 __slab_alloc.constprop.0+0x56/0xb0 mm/slub.c:3948
 __slab_alloc_node mm/slub.c:4023 [inline]
 slab_alloc_node mm/slub.c:4184 [inline]
 __do_kmalloc_node mm/slub.c:4326 [inline]
 __kmalloc_node_track_caller_noprof+0x2ee/0x510 mm/slub.c:4346
 kmalloc_reserve+0xef/0x2c0 net/core/skbuff.c:599
 __alloc_skb+0x166/0x380 net/core/skbuff.c:668
 alloc_skb include/linux/skbuff.h:1340 [inline]
 mld_newpack.isra.0+0x18e/0xa20 net/ipv6/mcast.c:1788
 add_grhead+0x299/0x340 net/ipv6/mcast.c:1899
 add_grec+0x112a/0x1680 net/ipv6/mcast.c:2037
 mld_send_initial_cr.part.0+0xe2/0x260 net/ipv6/mcast.c:2282
 mld_send_initial_cr include/linux/refcount.h:291 [inline]
 ipv6_mc_dad_complete+0x22c/0x2b0 net/ipv6/mcast.c:2293
 addrconf_dad_completed+0xd8a/0x10d0 net/ipv6/addrconf.c:4344
page last free pid 5856 tgid 5856 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1258 [inline]
 __free_frozen_pages+0x69d/0xff0 mm/page_alloc.c:2721
 discard_slab mm/slub.c:2716 [inline]
 __put_partials+0x16d/0x1c0 mm/slub.c:3185
 qlink_free mm/kasan/quarantine.c:163 [inline]
 qlist_free_all+0x4e/0x120 mm/kasan/quarantine.c:179
 kasan_quarantine_reduce+0x195/0x1e0 mm/kasan/quarantine.c:286
 __kasan_slab_alloc+0x69/0x90 mm/kasan/common.c:329
 kasan_slab_alloc include/linux/kasan.h:250 [inline]
 slab_post_alloc_hook mm/slub.c:4147 [inline]
 slab_alloc_node mm/slub.c:4196 [inline]
 __do_kmalloc_node mm/slub.c:4326 [inline]
 __kmalloc_noprof+0x1d4/0x510 mm/slub.c:4339
 kmalloc_noprof include/linux/slab.h:909 [inline]
 kzalloc_noprof include/linux/slab.h:1039 [inline]
 tomoyo_encode2+0x100/0x3e0 security/tomoyo/realpath.c:45
 tomoyo_encode+0x29/0x50 security/tomoyo/realpath.c:80
 tomoyo_realpath_from_path+0x18f/0x6e0 security/tomoyo/realpath.c:283
 tomoyo_get_realpath security/tomoyo/file.c:151 [inline]
 tomoyo_path_perm+0x274/0x460 security/tomoyo/file.c:822
 tomoyo_path_rmdir+0x91/0xe0 security/tomoyo/tomoyo.c:195
 security_path_rmdir+0x145/0x2b0 security/security.c:1949
 do_rmdir+0x27b/0x3c0 fs/namei.c:4506
 __do_sys_rmdir fs/namei.c:4528 [inline]
 __se_sys_rmdir fs/namei.c:4526 [inline]
 __x64_sys_rmdir+0xc5/0x110 fs/namei.c:4526
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xcd/0x260 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Memory state around the buggy address:
 ffff88807d682400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88807d682480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff88807d682500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                                       ^
 ffff88807d682580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88807d682600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================