======================================================
WARNING: possible circular locking dependency detected
5.14.0-rc4-syzkaller #0 Not tainted
------------------------------------------------------
syz-executor.2/14867 is trying to acquire lock:
ffff88803e3c1120 (sk_lock-AF_BLUETOOTH-BTPROTO_SCO){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1613 [inline]
ffff88803e3c1120 (sk_lock-AF_BLUETOOTH-BTPROTO_SCO){+.+.}-{0:0}, at: sco_conn_del+0x12a/0x2a0 net/bluetooth/sco.c:191

but task is already holding lock:
ffffffff8d2dc7c8 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_disconn_cfm include/net/bluetooth/hci_core.h:1497 [inline]
ffffffff8d2dc7c8 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_conn_hash_flush+0xda/0x260 net/bluetooth/hci_conn.c:1608

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #2 (hci_cb_list_lock){+.+.}-{3:3}:
       __mutex_lock_common kernel/locking/mutex.c:959 [inline]
       __mutex_lock+0x12a/0x10a0 kernel/locking/mutex.c:1104
       hci_connect_cfm include/net/bluetooth/hci_core.h:1482 [inline]
       hci_remote_features_evt net/bluetooth/hci_event.c:3263 [inline]
       hci_event_packet+0x2f4d/0x7c50 net/bluetooth/hci_event.c:6240
       hci_rx_work+0x4f8/0xd30 net/bluetooth/hci_core.c:5122
       process_one_work+0x98d/0x1630 kernel/workqueue.c:2276
       worker_thread+0x658/0x11f0 kernel/workqueue.c:2422
       kthread+0x3e5/0x4d0 kernel/kthread.c:319
       ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295

-> #1 (&hdev->lock){+.+.}-{3:3}:
       __mutex_lock_common kernel/locking/mutex.c:959 [inline]
       __mutex_lock+0x12a/0x10a0 kernel/locking/mutex.c:1104
       sco_connect net/bluetooth/sco.c:245 [inline]
       sco_sock_connect+0x227/0xa10 net/bluetooth/sco.c:601
       __sys_connect_file+0x155/0x1a0 net/socket.c:1879
       __sys_connect+0x161/0x190 net/socket.c:1896
       __do_sys_connect net/socket.c:1906 [inline]
       __se_sys_connect net/socket.c:1903 [inline]
       __x64_sys_connect+0x6f/0xb0 net/socket.c:1903
       do_syscall_x64 arch/x86/entry/common.c:50 [inline]
       do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
       entry_SYSCALL_64_after_hwframe+0x44/0xae

-> #0 (sk_lock-AF_BLUETOOTH-BTPROTO_SCO){+.+.}-{0:0}:
       check_prev_add kernel/locking/lockdep.c:3051 [inline]
       check_prevs_add kernel/locking/lockdep.c:3174 [inline]
       validate_chain kernel/locking/lockdep.c:3789 [inline]
       __lock_acquire+0x2a07/0x54a0 kernel/locking/lockdep.c:5015
       lock_acquire kernel/locking/lockdep.c:5625 [inline]
       lock_acquire+0x1ab/0x510 kernel/locking/lockdep.c:5590
       lock_sock_nested+0xca/0x120 net/core/sock.c:3170
       lock_sock include/net/sock.h:1613 [inline]
       sco_conn_del+0x12a/0x2a0 net/bluetooth/sco.c:191
       sco_disconn_cfm+0x71/0xb0 net/bluetooth/sco.c:1202
       hci_disconn_cfm include/net/bluetooth/hci_core.h:1500 [inline]
       hci_conn_hash_flush+0x127/0x260 net/bluetooth/hci_conn.c:1608
       hci_dev_do_close+0x528/0x1130 net/bluetooth/hci_core.c:1778
       hci_unregister_dev+0x1c0/0x5a0 net/bluetooth/hci_core.c:4015
       vhci_release+0x70/0xe0 drivers/bluetooth/hci_vhci.c:340
       __fput+0x288/0x920 fs/file_table.c:280
       task_work_run+0xdd/0x1a0 kernel/task_work.c:164
       exit_task_work include/linux/task_work.h:32 [inline]
       do_exit+0xbd4/0x2a60 kernel/exit.c:825
       do_group_exit+0x125/0x310 kernel/exit.c:922
       get_signal+0x47f/0x2160 kernel/signal.c:2808
       arch_do_signal_or_restart+0x2a9/0x1c40 arch/x86/kernel/signal.c:865
       handle_signal_work kernel/entry/common.c:148 [inline]
       exit_to_user_mode_loop kernel/entry/common.c:172 [inline]
       exit_to_user_mode_prepare+0x17d/0x290 kernel/entry/common.c:209
       __syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline]
       syscall_exit_to_user_mode+0x19/0x60 kernel/entry/common.c:302
       ret_from_fork+0x15/0x30 arch/x86/entry/entry_64.S:288

other info that might help us debug this:

Chain exists of:
  sk_lock-AF_BLUETOOTH-BTPROTO_SCO --> &hdev->lock --> hci_cb_list_lock

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(hci_cb_list_lock);
                               lock(&hdev->lock);
                               lock(hci_cb_list_lock);
  lock(sk_lock-AF_BLUETOOTH-BTPROTO_SCO);

 *** DEADLOCK ***

3 locks held by syz-executor.2/14867:
 #0: ffff8880353ccff0 (&hdev->req_lock){+.+.}-{3:3}, at: hci_dev_do_close+0xb7/0x1130 net/bluetooth/hci_core.c:1728
 #1: ffff8880353cc078 (&hdev->lock){+.+.}-{3:3}, at: hci_dev_do_close+0x22e/0x1130 net/bluetooth/hci_core.c:1765
 #2: ffffffff8d2dc7c8 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_disconn_cfm include/net/bluetooth/hci_core.h:1497 [inline]
 #2: ffffffff8d2dc7c8 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_conn_hash_flush+0xda/0x260 net/bluetooth/hci_conn.c:1608

stack backtrace:
CPU: 1 PID: 14867 Comm: syz-executor.2 Not tainted 5.14.0-rc4-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:105
 check_noncircular+0x25f/0x2e0 kernel/locking/lockdep.c:2131
 check_prev_add kernel/locking/lockdep.c:3051 [inline]
 check_prevs_add kernel/locking/lockdep.c:3174 [inline]
 validate_chain kernel/locking/lockdep.c:3789 [inline]
 __lock_acquire+0x2a07/0x54a0 kernel/locking/lockdep.c:5015
 lock_acquire kernel/locking/lockdep.c:5625 [inline]
 lock_acquire+0x1ab/0x510 kernel/locking/lockdep.c:5590
 lock_sock_nested+0xca/0x120 net/core/sock.c:3170
 lock_sock include/net/sock.h:1613 [inline]
 sco_conn_del+0x12a/0x2a0 net/bluetooth/sco.c:191
 sco_disconn_cfm+0x71/0xb0 net/bluetooth/sco.c:1202
 hci_disconn_cfm include/net/bluetooth/hci_core.h:1500 [inline]
 hci_conn_hash_flush+0x127/0x260 net/bluetooth/hci_conn.c:1608
 hci_dev_do_close+0x528/0x1130 net/bluetooth/hci_core.c:1778
 hci_unregister_dev+0x1c0/0x5a0 net/bluetooth/hci_core.c:4015
 vhci_release+0x70/0xe0 drivers/bluetooth/hci_vhci.c:340
 __fput+0x288/0x920 fs/file_table.c:280
 task_work_run+0xdd/0x1a0 kernel/task_work.c:164
 exit_task_work include/linux/task_work.h:32 [inline]
 do_exit+0xbd4/0x2a60 kernel/exit.c:825
 do_group_exit+0x125/0x310 kernel/exit.c:922
 get_signal+0x47f/0x2160 kernel/signal.c:2808
 arch_do_signal_or_restart+0x2a9/0x1c40 arch/x86/kernel/signal.c:865
 handle_signal_work kernel/entry/common.c:148 [inline]
 exit_to_user_mode_loop kernel/entry/common.c:172 [inline]
 exit_to_user_mode_prepare+0x17d/0x290 kernel/entry/common.c:209
 __syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline]
 syscall_exit_to_user_mode+0x19/0x60 kernel/entry/common.c:302
 ret_from_fork+0x15/0x30 arch/x86/entry/entry_64.S:288
RIP: 0033:0x4665d9
Code: Unable to access opcode bytes at RIP 0x4665af.
RSP: 002b:00007f6d191c4188 EFLAGS: 00000246 ORIG_RAX: 0000000000000038
RAX: 0000000000000000 RBX: 000000000056bf80 RCX: 00000000004665d9
RDX: 9999999999999999 RSI: 0000000000000000 RDI: 00040000000007fc
RBP: 00000000004bfcb9 R08: ffffffffffffffff R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056bf80
R13: 00007ffcc98fb13f R14: 00007f6d191c4300 R15: 0000000000022000
==================================================================
BUG: KASAN: use-after-free in instrument_atomic_read_write include/linux/instrumented.h:101 [inline]
BUG: KASAN: use-after-free in atomic_fetch_sub_release include/asm-generic/atomic-instrumented.h:167 [inline]
BUG: KASAN: use-after-free in __refcount_sub_and_test include/linux/refcount.h:272 [inline]
BUG: KASAN: use-after-free in __refcount_dec_and_test include/linux/refcount.h:315 [inline]
BUG: KASAN: use-after-free in refcount_dec_and_test include/linux/refcount.h:333 [inline]
BUG: KASAN: use-after-free in sock_put include/net/sock.h:1815 [inline]
BUG: KASAN: use-after-free in sco_conn_del+0x161/0x2a0 net/bluetooth/sco.c:196
Write of size 4 at addr ffff88803e3c1080 by task syz-executor.2/14867

CPU: 1 PID: 14867 Comm: syz-executor.2 Not tainted 5.14.0-rc4-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:105
 print_address_description.constprop.0.cold+0x6c/0x309 mm/kasan/report.c:233
 __kasan_report mm/kasan/report.c:419 [inline]
 kasan_report.cold+0x83/0xdf mm/kasan/report.c:436
 check_region_inline mm/kasan/generic.c:183 [inline]
 kasan_check_range+0x13d/0x180 mm/kasan/generic.c:189
 instrument_atomic_read_write include/linux/instrumented.h:101 [inline]
 atomic_fetch_sub_release include/asm-generic/atomic-instrumented.h:167 [inline]
 __refcount_sub_and_test include/linux/refcount.h:272 [inline]
 __refcount_dec_and_test include/linux/refcount.h:315 [inline]
 refcount_dec_and_test include/linux/refcount.h:333 [inline]
 sock_put include/net/sock.h:1815 [inline]
 sco_conn_del+0x161/0x2a0 net/bluetooth/sco.c:196
 sco_disconn_cfm+0x71/0xb0 net/bluetooth/sco.c:1202
 hci_disconn_cfm include/net/bluetooth/hci_core.h:1500 [inline]
 hci_conn_hash_flush+0x127/0x260 net/bluetooth/hci_conn.c:1608
 hci_dev_do_close+0x528/0x1130 net/bluetooth/hci_core.c:1778
 hci_unregister_dev+0x1c0/0x5a0 net/bluetooth/hci_core.c:4015
 vhci_release+0x70/0xe0 drivers/bluetooth/hci_vhci.c:340
 __fput+0x288/0x920 fs/file_table.c:280
 task_work_run+0xdd/0x1a0 kernel/task_work.c:164
 exit_task_work include/linux/task_work.h:32 [inline]
 do_exit+0xbd4/0x2a60 kernel/exit.c:825
 do_group_exit+0x125/0x310 kernel/exit.c:922
 get_signal+0x47f/0x2160 kernel/signal.c:2808
 arch_do_signal_or_restart+0x2a9/0x1c40 arch/x86/kernel/signal.c:865
 handle_signal_work kernel/entry/common.c:148 [inline]
 exit_to_user_mode_loop kernel/entry/common.c:172 [inline]
 exit_to_user_mode_prepare+0x17d/0x290 kernel/entry/common.c:209
 __syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline]
 syscall_exit_to_user_mode+0x19/0x60 kernel/entry/common.c:302
 ret_from_fork+0x15/0x30 arch/x86/entry/entry_64.S:288
RIP: 0033:0x4665d9
Code: Unable to access opcode bytes at RIP 0x4665af.
RSP: 002b:00007f6d191c4188 EFLAGS: 00000246 ORIG_RAX: 0000000000000038
RAX: 0000000000000000 RBX: 000000000056bf80 RCX: 00000000004665d9
RDX: 9999999999999999 RSI: 0000000000000000 RDI: 00040000000007fc
RBP: 00000000004bfcb9 R08: ffffffffffffffff R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056bf80
R13: 00007ffcc98fb13f R14: 00007f6d191c4300 R15: 0000000000022000

Allocated by task 14822:
 kasan_save_stack+0x1b/0x40 mm/kasan/common.c:38
 kasan_set_track mm/kasan/common.c:46 [inline]
 set_alloc_info mm/kasan/common.c:434 [inline]
 ____kasan_kmalloc mm/kasan/common.c:513 [inline]
 ____kasan_kmalloc mm/kasan/common.c:472 [inline]
 __kasan_kmalloc+0x9b/0xd0 mm/kasan/common.c:522
 kmalloc include/linux/slab.h:596 [inline]
 sk_prot_alloc+0x110/0x290 net/core/sock.c:1808
 sk_alloc+0x32/0xbc0 net/core/sock.c:1861
 sco_sock_alloc.constprop.0+0x31/0x220 net/bluetooth/sco.c:501
 sco_sock_create+0xd5/0x1b0 net/bluetooth/sco.c:536
 bt_sock_create+0x17c/0x340 net/bluetooth/af_bluetooth.c:130
 __sock_create+0x353/0x790 net/socket.c:1450
 sock_create net/socket.c:1501 [inline]
 __sys_socket+0xef/0x200 net/socket.c:1543
 __do_sys_socket net/socket.c:1552 [inline]
 __se_sys_socket net/socket.c:1550 [inline]
 __x64_sys_socket+0x6f/0xb0 net/socket.c:1550
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

Freed by task 14867:
 kasan_save_stack+0x1b/0x40 mm/kasan/common.c:38
 kasan_set_track+0x1c/0x30 mm/kasan/common.c:46
 kasan_set_free_info+0x20/0x30 mm/kasan/generic.c:360
 ____kasan_slab_free mm/kasan/common.c:366 [inline]
 ____kasan_slab_free mm/kasan/common.c:328 [inline]
 __kasan_slab_free+0xfb/0x130 mm/kasan/common.c:374
 kasan_slab_free include/linux/kasan.h:230 [inline]
 slab_free_hook mm/slub.c:1625 [inline]
 slab_free_freelist_hook+0xdf/0x240 mm/slub.c:1650
 slab_free mm/slub.c:3210 [inline]
 kfree+0xe4/0x530 mm/slub.c:4264
 sk_prot_free net/core/sock.c:1844 [inline]
 __sk_destruct+0x6a8/0x900 net/core/sock.c:1929
 sk_destruct+0xbd/0xe0 net/core/sock.c:1944
 __sk_free+0xef/0x3d0 net/core/sock.c:1955
 sk_free+0x78/0xa0 net/core/sock.c:1966
 sock_put include/net/sock.h:1816 [inline]
 sco_sock_kill+0x18d/0x1b0 net/bluetooth/sco.c:422
 sco_conn_del+0x153/0x2a0 net/bluetooth/sco.c:195
 sco_disconn_cfm+0x71/0xb0 net/bluetooth/sco.c:1202
 hci_disconn_cfm include/net/bluetooth/hci_core.h:1500 [inline]
 hci_conn_hash_flush+0x127/0x260 net/bluetooth/hci_conn.c:1608
 hci_dev_do_close+0x528/0x1130 net/bluetooth/hci_core.c:1778
 hci_unregister_dev+0x1c0/0x5a0 net/bluetooth/hci_core.c:4015
 vhci_release+0x70/0xe0 drivers/bluetooth/hci_vhci.c:340
 __fput+0x288/0x920 fs/file_table.c:280
 task_work_run+0xdd/0x1a0 kernel/task_work.c:164
 exit_task_work include/linux/task_work.h:32 [inline]
 do_exit+0xbd4/0x2a60 kernel/exit.c:825
 do_group_exit+0x125/0x310 kernel/exit.c:922
 get_signal+0x47f/0x2160 kernel/signal.c:2808
 arch_do_signal_or_restart+0x2a9/0x1c40 arch/x86/kernel/signal.c:865
 handle_signal_work kernel/entry/common.c:148 [inline]
 exit_to_user_mode_loop kernel/entry/common.c:172 [inline]
 exit_to_user_mode_prepare+0x17d/0x290 kernel/entry/common.c:209
 __syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline]
 syscall_exit_to_user_mode+0x19/0x60 kernel/entry/common.c:302
 ret_from_fork+0x15/0x30 arch/x86/entry/entry_64.S:288

The buggy address belongs to the object at ffff88803e3c1000
 which belongs to the cache kmalloc-2k of size 2048
The buggy address is located 128 bytes inside of
 2048-byte region [ffff88803e3c1000, ffff88803e3c1800)
The buggy address belongs to the page:
page:ffffea0000f8f000 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x3e3c0
head:ffffea0000f8f000 order:3 compound_mapcount:0 compound_pincount:0
flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000010200 dead000000000100 dead000000000122 ffff888010842000
raw: 0000000000000000 0000000080080008 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 3, migratetype Unmovable, gfp_mask 0xd28c0(GFP_NOWAIT|__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 5, ts 73813642786, free_ts 61784687158
 prep_new_page mm/page_alloc.c:2436 [inline]
 get_page_from_freelist+0xa72/0x2f80 mm/page_alloc.c:4169
 __alloc_pages+0x1b2/0x500 mm/page_alloc.c:5391
 alloc_pages+0x18c/0x2a0 mm/mempolicy.c:2244
 alloc_slab_page mm/slub.c:1688 [inline]
 allocate_slab+0x32e/0x4b0 mm/slub.c:1828
 new_slab mm/slub.c:1891 [inline]
 new_slab_objects mm/slub.c:2637 [inline]
 ___slab_alloc+0x4ba/0x820 mm/slub.c:2800
 __slab_alloc.constprop.0+0xa7/0xf0 mm/slub.c:2840
 slab_alloc_node mm/slub.c:2922 [inline]
 __kmalloc_node_track_caller+0x2e3/0x360 mm/slub.c:4650
 kmalloc_reserve net/core/skbuff.c:355 [inline]
 pskb_expand_head+0x15e/0x1060 net/core/skbuff.c:1696
 netlink_trim+0x1ea/0x240 net/netlink/af_netlink.c:1296
 netlink_broadcast_filtered+0x65/0xdc0 net/netlink/af_netlink.c:1501
 netlink_broadcast net/netlink/af_netlink.c:1546 [inline]
 nlmsg_multicast include/net/netlink.h:1033 [inline]
 nlmsg_notify+0x90/0x250 net/netlink/af_netlink.c:2547
 rtnl_notify net/core/rtnetlink.c:741 [inline]
 rtmsg_ifinfo_send net/core/rtnetlink.c:3835 [inline]
 rtmsg_ifinfo_event net/core/rtnetlink.c:3850 [inline]
 rtmsg_ifinfo_event net/core/rtnetlink.c:3838 [inline]
 rtmsg_ifinfo+0xf0/0x120 net/core/rtnetlink.c:3856
 netdev_state_change net/core/dev.c:1516 [inline]
 netdev_state_change+0x114/0x130 net/core/dev.c:1507
 linkwatch_do_dev+0x151/0x1b0 net/core/link_watch.c:167
 __linkwatch_run_queue+0x1ea/0x630 net/core/link_watch.c:212
 linkwatch_event+0x4a/0x60 net/core/link_watch.c:251
page last free stack trace:
 reset_page_owner include/linux/page_owner.h:24 [inline]
 free_pages_prepare mm/page_alloc.c:1346 [inline]
 free_pcp_prepare+0x2c5/0x780 mm/page_alloc.c:1397
 free_unref_page_prepare mm/page_alloc.c:3332 [inline]
 free_unref_page+0x19/0x690 mm/page_alloc.c:3411
 __vunmap+0x783/0xb70 mm/vmalloc.c:2587
 __vfree+0x3c/0xd0 mm/vmalloc.c:2635
 vfree+0x5a/0x90 mm/vmalloc.c:2666
 kcov_put kernel/kcov.c:408 [inline]
 kcov_put+0x26/0x40 kernel/kcov.c:404
 kcov_close+0xc/0x10 kernel/kcov.c:510
 __fput+0x288/0x920 fs/file_table.c:280
 task_work_run+0xdd/0x1a0 kernel/task_work.c:164
 exit_task_work include/linux/task_work.h:32 [inline]
 do_exit+0xbd4/0x2a60 kernel/exit.c:825
 do_group_exit+0x125/0x310 kernel/exit.c:922
 get_signal+0x47f/0x2160 kernel/signal.c:2808
 arch_do_signal_or_restart+0x2a9/0x1c40 arch/x86/kernel/signal.c:865
 handle_signal_work kernel/entry/common.c:148 [inline]
 exit_to_user_mode_loop kernel/entry/common.c:172 [inline]
 exit_to_user_mode_prepare+0x17d/0x290 kernel/entry/common.c:209
 __syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline]
 syscall_exit_to_user_mode+0x19/0x60 kernel/entry/common.c:302
 do_syscall_64+0x42/0xb0 arch/x86/entry/common.c:86

Memory state around the buggy address:
 ffff88803e3c0f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff88803e3c1000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff88803e3c1080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                   ^
 ffff88803e3c1100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88803e3c1180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================