=========================
WARNING: held lock freed!
syzkaller #0 Tainted: G             L     
-------------------------
syz.1.6140/15996 is freeing memory ffff888040dc7000-ffff888040dc77ff, with a lock still held there!
ffff888040dc7260 (sk_lock-AF_BLUETOOTH-BTPROTO_L2CAP){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1700 [inline]
ffff888040dc7260 (sk_lock-AF_BLUETOOTH-BTPROTO_L2CAP){+.+.}-{0:0}, at: bt_accept_dequeue+0x244/0x690 net/bluetooth/af_bluetooth.c:279
3 locks held by syz.1.6140/15996:
 #0: ffff88803df8de08 (&sb->s_type->i_mutex_key#12){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1027 [inline]
 #0: ffff88803df8de08 (&sb->s_type->i_mutex_key#12){+.+.}-{4:4}, at: __sock_release+0x86/0x260 net/socket.c:661
 #1: ffff8880564e1260 (sk_lock-AF_BLUETOOTH-BTPROTO_L2CAP/2){+.+.}-{0:0}, at: l2cap_sock_release+0x61/0x280 net/bluetooth/l2cap_sock.c:1425
 #2: ffff888040dc7260 (sk_lock-AF_BLUETOOTH-BTPROTO_L2CAP){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1700 [inline]
 #2: ffff888040dc7260 (sk_lock-AF_BLUETOOTH-BTPROTO_L2CAP){+.+.}-{0:0}, at: bt_accept_dequeue+0x244/0x690 net/bluetooth/af_bluetooth.c:279

stack backtrace:
CPU: 2 UID: 0 PID: 15996 Comm: syz.1.6140 Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120
 print_freed_lock_bug kernel/locking/lockdep.c:6693 [inline]
 debug_check_no_locks_freed+0x115/0x120 kernel/locking/lockdep.c:6728
 slab_free_hook mm/slub.c:2468 [inline]
 slab_free mm/slub.c:6674 [inline]
 kfree+0x15d/0x690 mm/slub.c:6882
 sk_prot_free net/core/sock.c:2284 [inline]
 __sk_destruct+0x8ab/0xbb0 net/core/sock.c:2384
 sk_destruct+0xc8/0xf0 net/core/sock.c:2412
 __sk_free+0xf4/0x3e0 net/core/sock.c:2423
 sk_free+0x61/0x90 net/core/sock.c:2434
 sock_put include/net/sock.h:1998 [inline]
 bt_accept_unlink+0x1e4/0x2f0 net/bluetooth/af_bluetooth.c:262
 bt_accept_dequeue+0x576/0x690 net/bluetooth/af_bluetooth.c:308
 l2cap_sock_cleanup_listen+0x5c/0x2d0 net/bluetooth/l2cap_sock.c:1454
 l2cap_sock_release+0x69/0x280 net/bluetooth/l2cap_sock.c:1426
 __sock_release+0xb3/0x260 net/socket.c:662
 sock_close+0x1c/0x30 net/socket.c:1455
 __fput+0x3ff/0xb40 fs/file_table.c:468
 task_work_run+0x150/0x240 kernel/task_work.c:233
 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
 __exit_to_user_mode_loop kernel/entry/common.c:44 [inline]
 exit_to_user_mode_loop+0x100/0x4b0 kernel/entry/common.c:75
 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline]
 syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline]
 syscall_exit_to_user_mode_work include/linux/entry-common.h:159 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:194 [inline]
 do_syscall_64+0x4fe/0xf80 arch/x86/entry/syscall_64.c:100
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f92b979acb9
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffc4c3ace78 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4
RAX: 0000000000000000 RBX: 00007f92b9a17da0 RCX: 00007f92b979acb9
RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003
RBP: 00007f92b9a17da0 R08: 00007f92b9a16128 R09: 0000000000000000
R10: 00000000003ffc64 R11: 0000000000000246 R12: 0000000000094007
R13: 00007f92b9a1618c R14: 0000000000093d94 R15: 00007f92b9a16180
 </TASK>
==================================================================
BUG: KASAN: slab-use-after-free in debug_spin_lock_before kernel/locking/spinlock_debug.c:86 [inline]
BUG: KASAN: slab-use-after-free in do_raw_spin_lock+0x23b/0x260 kernel/locking/spinlock_debug.c:115
Read of size 4 at addr ffff888040dc71cc by task syz.1.6140/15996

CPU: 2 UID: 0 PID: 15996 Comm: syz.1.6140 Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:378 [inline]
 print_report+0x156/0x4c9 mm/kasan/report.c:482
 kasan_report+0xdf/0x1a0 mm/kasan/report.c:595
 debug_spin_lock_before kernel/locking/spinlock_debug.c:86 [inline]
 do_raw_spin_lock+0x23b/0x260 kernel/locking/spinlock_debug.c:115
 spin_lock_bh include/linux/spinlock.h:356 [inline]
 release_sock+0x21/0x220 net/core/sock.c:3793
 bt_accept_dequeue+0x564/0x690 net/bluetooth/af_bluetooth.c:312
 l2cap_sock_cleanup_listen+0x5c/0x2d0 net/bluetooth/l2cap_sock.c:1454
 l2cap_sock_release+0x69/0x280 net/bluetooth/l2cap_sock.c:1426
 __sock_release+0xb3/0x260 net/socket.c:662
 sock_close+0x1c/0x30 net/socket.c:1455
 __fput+0x3ff/0xb40 fs/file_table.c:468
 task_work_run+0x150/0x240 kernel/task_work.c:233
 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
 __exit_to_user_mode_loop kernel/entry/common.c:44 [inline]
 exit_to_user_mode_loop+0x100/0x4b0 kernel/entry/common.c:75
 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline]
 syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline]
 syscall_exit_to_user_mode_work include/linux/entry-common.h:159 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:194 [inline]
 do_syscall_64+0x4fe/0xf80 arch/x86/entry/syscall_64.c:100
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f92b979acb9
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffc4c3ace78 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4
RAX: 0000000000000000 RBX: 00007f92b9a17da0 RCX: 00007f92b979acb9
RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003
RBP: 00007f92b9a17da0 R08: 00007f92b9a16128 R09: 0000000000000000
R10: 00000000003ffc64 R11: 0000000000000246 R12: 0000000000094007
R13: 00007f92b9a1618c R14: 0000000000093d94 R15: 00007f92b9a16180
 </TASK>

Allocated by task 13331:
 kasan_save_stack+0x30/0x50 mm/kasan/common.c:57
 kasan_save_track+0x14/0x30 mm/kasan/common.c:78
 poison_kmalloc_redzone mm/kasan/common.c:398 [inline]
 __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:415
 kasan_kmalloc include/linux/kasan.h:263 [inline]
 __do_kmalloc_node mm/slub.c:5657 [inline]
 __kmalloc_noprof+0x347/0x9c0 mm/slub.c:5669
 kmalloc_noprof include/linux/slab.h:961 [inline]
 sk_prot_alloc+0x10b/0x2a0 net/core/sock.c:2245
 sk_alloc+0x36/0xe80 net/core/sock.c:2301
 bt_sock_alloc+0x3b/0x3a0 net/bluetooth/af_bluetooth.c:151
 l2cap_sock_alloc.constprop.0+0x33/0x1e0 net/bluetooth/l2cap_sock.c:1897
 l2cap_sock_new_connection_cb+0x101/0x260 net/bluetooth/l2cap_sock.c:1485
 l2cap_connect_cfm+0x4e2/0x1010 net/bluetooth/l2cap_core.c:7288
 hci_connect_cfm include/net/bluetooth/hci_core.h:2131 [inline]
 hci_remote_features_evt+0x4f4/0x9b0 net/bluetooth/hci_event.c:3729
 hci_event_func net/bluetooth/hci_event.c:7719 [inline]
 hci_event_packet+0xa86/0x11c0 net/bluetooth/hci_event.c:7773
 hci_rx_work+0x451/0xfc0 net/bluetooth/hci_core.c:4076
 process_one_work+0x9c2/0x1840 kernel/workqueue.c:3257
 process_scheduled_works kernel/workqueue.c:3340 [inline]
 worker_thread+0x5da/0xe40 kernel/workqueue.c:3421
 kthread+0x3b3/0x730 kernel/kthread.c:463
 ret_from_fork+0x754/0xaf0 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246

Freed by task 15996:
 kasan_save_stack+0x30/0x50 mm/kasan/common.c:57
 kasan_save_track+0x14/0x30 mm/kasan/common.c:78
 kasan_save_free_info+0x3b/0x70 mm/kasan/generic.c:584
 poison_slab_object mm/kasan/common.c:253 [inline]
 __kasan_slab_free+0x5f/0x80 mm/kasan/common.c:285
 kasan_slab_free include/linux/kasan.h:235 [inline]
 slab_free_hook mm/slub.c:2540 [inline]
 slab_free mm/slub.c:6674 [inline]
 kfree+0x1c7/0x690 mm/slub.c:6882
 sk_prot_free net/core/sock.c:2284 [inline]
 __sk_destruct+0x8ab/0xbb0 net/core/sock.c:2384
 sk_destruct+0xc8/0xf0 net/core/sock.c:2412
 __sk_free+0xf4/0x3e0 net/core/sock.c:2423
 sk_free+0x61/0x90 net/core/sock.c:2434
 sock_put include/net/sock.h:1998 [inline]
 bt_accept_unlink+0x1e4/0x2f0 net/bluetooth/af_bluetooth.c:262
 bt_accept_dequeue+0x576/0x690 net/bluetooth/af_bluetooth.c:308
 l2cap_sock_cleanup_listen+0x5c/0x2d0 net/bluetooth/l2cap_sock.c:1454
 l2cap_sock_release+0x69/0x280 net/bluetooth/l2cap_sock.c:1426
 __sock_release+0xb3/0x260 net/socket.c:662
 sock_close+0x1c/0x30 net/socket.c:1455
 __fput+0x3ff/0xb40 fs/file_table.c:468
 task_work_run+0x150/0x240 kernel/task_work.c:233
 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
 __exit_to_user_mode_loop kernel/entry/common.c:44 [inline]
 exit_to_user_mode_loop+0x100/0x4b0 kernel/entry/common.c:75
 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline]
 syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline]
 syscall_exit_to_user_mode_work include/linux/entry-common.h:159 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:194 [inline]
 do_syscall_64+0x4fe/0xf80 arch/x86/entry/syscall_64.c:100
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

The buggy address belongs to the object at ffff888040dc7000
 which belongs to the cache kmalloc-2k of size 2048
The buggy address is located 460 bytes inside of
 freed 2048-byte region [ffff888040dc7000, ffff888040dc7800)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x40dc0
head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 00fff00000000040 ffff88801b842f00 ffffea00015b5a00 dead000000000002
raw: 0000000000000000 0000000080080008 00000000f5000000 0000000000000000
head: 00fff00000000040 ffff88801b842f00 ffffea00015b5a00 dead000000000002
head: 0000000000000000 0000000080080008 00000000f5000000 0000000000000000
head: 00fff00000000003 ffffea0001037001 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 0xd2820(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 77, tgid 77 (kworker/0:2), ts 436687253740, free_ts 436664869394
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x1e1/0x250 mm/page_alloc.c:1884
 prep_new_page mm/page_alloc.c:1892 [inline]
 get_page_from_freelist+0xe3d/0x2e10 mm/page_alloc.c:3945
 __alloc_frozen_pages_noprof+0x26c/0x2410 mm/page_alloc.c:5240
 alloc_pages_mpol+0x1fb/0x550 mm/mempolicy.c:2486
 alloc_slab_page mm/slub.c:3075 [inline]
 allocate_slab mm/slub.c:3248 [inline]
 new_slab+0x2c4/0x440 mm/slub.c:3302
 ___slab_alloc+0xda3/0x1ca0 mm/slub.c:4656
 __slab_alloc.isra.0+0x63/0x110 mm/slub.c:4779
 __slab_alloc_node mm/slub.c:4855 [inline]
 slab_alloc_node mm/slub.c:5251 [inline]
 __do_kmalloc_node mm/slub.c:5656 [inline]
 __kmalloc_node_track_caller_noprof+0x629/0x9d0 mm/slub.c:5768
 kmalloc_reserve+0xef/0x2c0 net/core/skbuff.c:608
 __alloc_skb+0x186/0x410 net/core/skbuff.c:690
 alloc_skb include/linux/skbuff.h:1383 [inline]
 igmpv3_newpack+0x1c0/0x1260 net/ipv4/igmp.c:365
 add_grhead+0x267/0x300 net/ipv4/igmp.c:446
 add_grec+0x1114/0x1570 net/ipv4/igmp.c:580
 igmpv3_send_report.isra.0+0xa8/0x5c0 net/ipv4/igmp.c:620
 igmp_send_report.isra.0+0xad5/0xd10 net/ipv4/igmp.c:744
 ip_mc_rejoin_groups net/ipv4/igmp.c:1753 [inline]
 igmp_netdev_event+0x52f/0x890 net/ipv4/igmp.c:3166
page last free pid 77 tgid 77 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1433 [inline]
 __free_frozen_pages+0x822/0x1130 mm/page_alloc.c:2973
 discard_slab mm/slub.c:3346 [inline]
 __put_partials+0x127/0x160 mm/slub.c:3886
 qlink_free mm/kasan/quarantine.c:163 [inline]
 qlist_free_all+0x47/0xe0 mm/kasan/quarantine.c:179
 kasan_quarantine_reduce+0x1a0/0x1f0 mm/kasan/quarantine.c:286
 __kasan_slab_alloc+0x69/0x90 mm/kasan/common.c:350
 kasan_slab_alloc include/linux/kasan.h:253 [inline]
 slab_post_alloc_hook mm/slub.c:4953 [inline]
 slab_alloc_node mm/slub.c:5263 [inline]
 kmem_cache_alloc_node_noprof+0x303/0x880 mm/slub.c:5315
 __alloc_skb+0x156/0x410 net/core/skbuff.c:679
 alloc_skb include/linux/skbuff.h:1383 [inline]
 nlmsg_new include/net/netlink.h:1055 [inline]
 rtmsg_ifinfo_build_skb+0x81/0x260 net/core/rtnetlink.c:4407
 rtmsg_ifinfo_event net/core/rtnetlink.c:4449 [inline]
 rtmsg_ifinfo_event net/core/rtnetlink.c:4439 [inline]
 rtnetlink_event+0x137/0x1f0 net/core/rtnetlink.c:7018
 notifier_call_chain+0x99/0x3b0 kernel/notifier.c:85
 call_netdevice_notifiers_info+0xbe/0x110 net/core/dev.c:2243
 call_netdevice_notifiers_extack net/core/dev.c:2281 [inline]
 call_netdevice_notifiers+0x7c/0xb0 net/core/dev.c:2295
 team_mcast_rejoin_work drivers/net/team/team_core.c:692 [inline]
 team_mcast_rejoin_work+0xf8/0x230 drivers/net/team/team_core.c:676
 process_one_work+0x9c2/0x1840 kernel/workqueue.c:3257
 process_scheduled_works kernel/workqueue.c:3340 [inline]
 worker_thread+0x5da/0xe40 kernel/workqueue.c:3421
 kthread+0x3b3/0x730 kernel/kthread.c:463

Memory state around the buggy address:
 ffff888040dc7080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888040dc7100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff888040dc7180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                              ^
 ffff888040dc7200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888040dc7280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================