==================================================================
BUG: KASAN: slab-use-after-free in hci_send_acl+0xeb7/0x1050 net/bluetooth/hci_core.c:3231
Read of size 8 at addr ffff8880612eca18 by task kworker/3:4/5207

CPU: 3 PID: 5207 Comm: kworker/3:4 Not tainted 6.6.0-syzkaller #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
Workqueue: events l2cap_info_timeout
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0xd9/0x1b0 lib/dump_stack.c:106
 print_address_description mm/kasan/report.c:364 [inline]
 print_report+0xc4/0x620 mm/kasan/report.c:475
 kasan_report+0xda/0x110 mm/kasan/report.c:588
 hci_send_acl+0xeb7/0x1050 net/bluetooth/hci_core.c:3231
 l2cap_send_cmd+0x6dd/0x920 net/bluetooth/l2cap_core.c:977
 l2cap_send_conn_req+0x1e5/0x260 net/bluetooth/l2cap_core.c:1286
 l2cap_start_connection+0x11e/0x420 net/bluetooth/l2cap_core.c:1514
 l2cap_conn_start+0x7ae/0xa40 net/bluetooth/l2cap_core.c:1661
 process_one_work+0x884/0x15c0 kernel/workqueue.c:2630
 process_scheduled_works kernel/workqueue.c:2703 [inline]
 worker_thread+0x8b9/0x1290 kernel/workqueue.c:2784
 kthread+0x33c/0x440 kernel/kthread.c:388
 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:304
 </TASK>

Allocated by task 19851:
 kasan_save_stack+0x33/0x50 mm/kasan/common.c:45
 kasan_set_track+0x25/0x30 mm/kasan/common.c:52
 ____kasan_kmalloc mm/kasan/common.c:374 [inline]
 __kasan_kmalloc+0xa2/0xb0 mm/kasan/common.c:383
 kmalloc include/linux/slab.h:599 [inline]
 kzalloc include/linux/slab.h:720 [inline]
 hci_chan_create+0xa6/0x3d0 net/bluetooth/hci_conn.c:2723
 l2cap_conn_add.part.0+0x1a/0xdf0 net/bluetooth/l2cap_core.c:7841
 l2cap_conn_add include/net/bluetooth/hci_core.h:1521 [inline]
 l2cap_chan_connect+0x15de/0x2170 net/bluetooth/l2cap_core.c:8053
 bt_6lowpan_connect net/bluetooth/6lowpan.c:894 [inline]
 lowpan_control_write+0x3d6/0x730 net/bluetooth/6lowpan.c:1129
 full_proxy_write+0x124/0x190 fs/debugfs/file.c:236
 vfs_write+0x2a4/0xe40 fs/read_write.c:582
 ksys_write+0x12f/0x250 fs/read_write.c:637
 do_syscall_32_irqs_on arch/x86/entry/common.c:112 [inline]
 __do_fast_syscall_32+0x61/0xe0 arch/x86/entry/common.c:178
 do_fast_syscall_32+0x33/0x70 arch/x86/entry/common.c:203
 entry_SYSENTER_compat_after_hwframe+0x70/0x82

Freed by task 62:
 kasan_save_stack+0x33/0x50 mm/kasan/common.c:45
 kasan_set_track+0x25/0x30 mm/kasan/common.c:52
 kasan_save_free_info+0x2b/0x40 mm/kasan/generic.c:522
 ____kasan_slab_free mm/kasan/common.c:236 [inline]
 ____kasan_slab_free+0x15b/0x1b0 mm/kasan/common.c:200
 kasan_slab_free include/linux/kasan.h:164 [inline]
 slab_free_hook mm/slub.c:1800 [inline]
 slab_free_freelist_hook+0x114/0x1e0 mm/slub.c:1826
 slab_free mm/slub.c:3809 [inline]
 __kmem_cache_free+0xb8/0x2f0 mm/slub.c:3822
 hci_chan_list_flush+0x81/0xf0 net/bluetooth/hci_conn.c:2763
 hci_conn_cleanup net/bluetooth/hci_conn.c:152 [inline]
 hci_conn_del+0x201/0xd80 net/bluetooth/hci_conn.c:1156
 hci_abort_conn_sync+0x573/0xe10 net/bluetooth/hci_sync.c:5428
 abort_conn_sync+0x187/0x390 net/bluetooth/hci_conn.c:2910
 hci_cmd_sync_work+0x1a4/0x410 net/bluetooth/hci_sync.c:306
 process_one_work+0x884/0x15c0 kernel/workqueue.c:2630
 process_scheduled_works kernel/workqueue.c:2703 [inline]
 worker_thread+0x8b9/0x1290 kernel/workqueue.c:2784
 kthread+0x33c/0x440 kernel/kthread.c:388
 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:304

Last potentially related work creation:
 kasan_save_stack+0x33/0x50 mm/kasan/common.c:45
 __kasan_record_aux_stack+0xbc/0xd0 mm/kasan/generic.c:492
 kvfree_call_rcu+0x70/0xbe0 kernel/rcu/tree.c:3372
 kernfs_unlink_open_file+0x3b6/0x4b0 fs/kernfs/file.c:633
 kernfs_fop_release+0xec/0x1e0 fs/kernfs/file.c:805
 __fput+0x3f7/0xa70 fs/file_table.c:384
 __fput_sync+0x47/0x50 fs/file_table.c:465
 __do_sys_close fs/open.c:1572 [inline]
 __se_sys_close fs/open.c:1557 [inline]
 __x64_sys_close+0x87/0xf0 fs/open.c:1557
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x38/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

Second to last potentially related work creation:
 kasan_save_stack+0x33/0x50 mm/kasan/common.c:45
 __kasan_record_aux_stack+0xbc/0xd0 mm/kasan/generic.c:492
 kvfree_call_rcu+0x70/0xbe0 kernel/rcu/tree.c:3372
 kernfs_unlink_open_file+0x3b6/0x4b0 fs/kernfs/file.c:633
 kernfs_fop_release+0xec/0x1e0 fs/kernfs/file.c:805
 __fput+0x3f7/0xa70 fs/file_table.c:384
 __fput_sync+0x47/0x50 fs/file_table.c:465
 __do_sys_close fs/open.c:1572 [inline]
 __se_sys_close fs/open.c:1557 [inline]
 __x64_sys_close+0x87/0xf0 fs/open.c:1557
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x38/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

The buggy address belongs to the object at ffff8880612eca00
 which belongs to the cache kmalloc-128 of size 128
The buggy address is located 24 bytes inside of
 freed 128-byte region [ffff8880612eca00, ffff8880612eca80)

The buggy address belongs to the physical page:
page:ffffea000184bb00 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff8880612ec800 pfn:0x612ec
flags: 0x4fff00000000800(slab|node=1|zone=1|lastcpupid=0x7ff)
page_type: 0xffffffff()
raw: 04fff00000000800 ffff888012c428c0 ffffea000184bc50 ffffea00018a4410
raw: ffff8880612ec800 0000000000100006 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 0, migratetype Unmovable, gfp_mask 0x112cc0(GFP_USER|__GFP_NOWARN|__GFP_NORETRY), pid 5161, tgid 5161 (syz-executor.2), ts 52955962301, free_ts 52955915278
 set_page_owner include/linux/page_owner.h:31 [inline]
 post_alloc_hook+0x2cf/0x340 mm/page_alloc.c:1536
 prep_new_page mm/page_alloc.c:1543 [inline]
 get_page_from_freelist+0xee0/0x2f20 mm/page_alloc.c:3170
 __alloc_pages+0x1d0/0x4a0 mm/page_alloc.c:4426
 __alloc_pages_node include/linux/gfp.h:237 [inline]
 alloc_slab_page mm/slub.c:1872 [inline]
 allocate_slab+0xa1/0x380 mm/slub.c:2017
 new_slab mm/slub.c:2070 [inline]
 ___slab_alloc+0x8c7/0x1580 mm/slub.c:3223
 __slab_alloc.constprop.0+0x56/0xa0 mm/slub.c:3322
 __slab_alloc_node mm/slub.c:3375 [inline]
 slab_alloc_node mm/slub.c:3468 [inline]
 __kmem_cache_alloc_node+0x131/0x340 mm/slub.c:3517
 __do_kmalloc_node mm/slab_common.c:1025 [inline]
 __kmalloc_node+0x52/0x110 mm/slab_common.c:1033
 kmalloc_array_node include/linux/slab.h:697 [inline]
 kcalloc_node include/linux/slab.h:702 [inline]
 memcg_alloc_slab_cgroups+0xa9/0x170 mm/memcontrol.c:2895
 memcg_slab_post_alloc_hook+0xaa/0x390 mm/slab.h:530
 slab_post_alloc_hook mm/slab.h:770 [inline]
 slab_alloc_node mm/slub.c:3478 [inline]
 __kmem_cache_alloc_node+0x1cb/0x340 mm/slub.c:3517
 __do_kmalloc_node mm/slab_common.c:1025 [inline]
 __kmalloc_node+0x52/0x110 mm/slab_common.c:1033
 kmalloc_node include/linux/slab.h:619 [inline]
 kvmalloc_node+0x99/0x1a0 mm/util.c:607
 kvmalloc include/linux/slab.h:737 [inline]
 xt_alloc_table_info+0x3e/0xa0 net/netfilter/x_tables.c:1192
 compat_do_replace.constprop.0+0x1a2/0x4b0 net/ipv6/netfilter/ip6_tables.c:1515
 do_ip6t_set_ctl+0x5e4/0xbc0 net/ipv6/netfilter/ip6_tables.c:1633
page last free stack trace:
 reset_page_owner include/linux/page_owner.h:24 [inline]
 free_pages_prepare mm/page_alloc.c:1136 [inline]
 free_unref_page_prepare+0x476/0xa40 mm/page_alloc.c:2312
 free_unref_page+0x33/0x3b0 mm/page_alloc.c:2405
 vfree+0x181/0x7a0 mm/vmalloc.c:2842
 xt_compat_flush_offsets+0x8f/0x160 net/netfilter/x_tables.c:691
 compat_get_entries+0x234/0x850 net/ipv6/netfilter/ip6_tables.c:1610
 do_ip6t_get_ctl+0x569/0xab0 net/ipv6/netfilter/ip6_tables.c:1666
 nf_getsockopt+0x76/0xe0 net/netfilter/nf_sockopt.c:116
 ipv6_getsockopt+0x1f9/0x2b0 net/ipv6/ipv6_sockglue.c:1500
 tcp_getsockopt+0x97/0xf0 net/ipv4/tcp.c:4280
 __sys_getsockopt+0x220/0x6a0 net/socket.c:2371
 __do_compat_sys_socketcall+0x428/0x700 net/compat.c:494
 do_syscall_32_irqs_on arch/x86/entry/common.c:112 [inline]
 __do_fast_syscall_32+0x61/0xe0 arch/x86/entry/common.c:178
 do_fast_syscall_32+0x33/0x70 arch/x86/entry/common.c:203
 entry_SYSENTER_compat_after_hwframe+0x70/0x82

Memory state around the buggy address:
 ffff8880612ec900: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff8880612ec980: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff8880612eca00: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                            ^
 ffff8880612eca80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff8880612ecb00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
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