[syzbot] INFO: task hung in hci_power_on

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 9d004b2f4fea Merge tag 'cxl-for-5.19' of git://git.kernel...
git tree: upstream
console+strace: https://syzkaller.appspot.com/x/log.txt?x=1644de7bf00000
kernel config: https://syzkaller.appspot.com/x/.config?x=3c367f7c347f1679
dashboard link: https://syzkaller.appspot.com/bug?extid=8d7b9ced2a99394b0a50
compiler: Debian clang version 13.0.1-++20220126092033+75e33f71c2da-1~exp1~20220126212112.63, GNU ld (GNU Binutils for Debian) 2.35.2
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=103f3755f00000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=17f4cf3df00000

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+8d7b9c...@syzkaller.appspotmail.com

INFO: task kworker/u5:0:47 blocked for more than 143 seconds.
Not tainted 5.18.0-syzkaller-10643-g9d004b2f4fea #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u5:0 state:D stack:26752 pid: 47 ppid: 2 flags:0x00004000
Workqueue: hci2 hci_power_on
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5116 [inline]
__schedule+0x957/0xec0 kernel/sched/core.c:6431
schedule+0xeb/0x1b0 kernel/sched/core.c:6503
schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6562
__mutex_lock_common+0xecf/0x26c0 kernel/locking/mutex.c:679
__mutex_lock kernel/locking/mutex.c:747 [inline]
mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:799
hci_dev_do_open net/bluetooth/hci_core.c:480 [inline]
hci_power_on+0x178/0x650 net/bluetooth/hci_core.c:963
process_one_work+0x81c/0xd10 kernel/workqueue.c:2289
worker_thread+0xb14/0x1330 kernel/workqueue.c:2436
kthread+0x266/0x300 kernel/kthread.c:376
ret_from_fork+0x1f/0x30
</TASK>
INFO: task kworker/u5:8:3667 blocked for more than 143 seconds.
Not tainted 5.18.0-syzkaller-10643-g9d004b2f4fea #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u5:8 state:D stack:26752 pid: 3667 ppid: 2 flags:0x00004000
Workqueue: hci3 hci_power_on
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5116 [inline]
__schedule+0x957/0xec0 kernel/sched/core.c:6431
schedule+0xeb/0x1b0 kernel/sched/core.c:6503
schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6562
__mutex_lock_common+0xecf/0x26c0 kernel/locking/mutex.c:679
__mutex_lock kernel/locking/mutex.c:747 [inline]
mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:799
hci_dev_do_open net/bluetooth/hci_core.c:480 [inline]
hci_power_on+0x178/0x650 net/bluetooth/hci_core.c:963
process_one_work+0x81c/0xd10 kernel/workqueue.c:2289
worker_thread+0xb14/0x1330 kernel/workqueue.c:2436
kthread+0x266/0x300 kernel/kthread.c:376
ret_from_fork+0x1f/0x30
</TASK>
INFO: task syz-executor174:3932 blocked for more than 143 seconds.
Not tainted 5.18.0-syzkaller-10643-g9d004b2f4fea #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor174 state:D stack:26584 pid: 3932 ppid: 3611 flags:0x00004002
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5116 [inline]
__schedule+0x957/0xec0 kernel/sched/core.c:6431
schedule+0xeb/0x1b0 kernel/sched/core.c:6503
schedule_timeout+0xac/0x300 kernel/time/timer.c:1911
do_wait_for_common+0x3ea/0x560 kernel/sched/completion.c:85
__wait_for_common kernel/sched/completion.c:106 [inline]
wait_for_common kernel/sched/completion.c:117 [inline]
wait_for_completion+0x46/0x60 kernel/sched/completion.c:138
__flush_work kernel/workqueue.c:3075 [inline]
__cancel_work_timer+0x585/0x740 kernel/workqueue.c:3162
hci_dev_close_sync+0x31/0xcc0 net/bluetooth/hci_sync.c:4091
hci_dev_do_close net/bluetooth/hci_core.c:553 [inline]
hci_unregister_dev+0x1b1/0x460 net/bluetooth/hci_core.c:2685
hci_uart_tty_close+0x1a7/0x280 drivers/bluetooth/hci_ldisc.c:548
tty_ldisc_kill drivers/tty/tty_ldisc.c:608 [inline]
tty_ldisc_release+0x23c/0x510 drivers/tty/tty_ldisc.c:776
tty_release_struct+0x27/0xd0 drivers/tty/tty_io.c:1694
tty_release+0xc06/0xe60 drivers/tty/tty_io.c:1865
__fput+0x3b9/0x820 fs/file_table.c:317
task_work_run+0x146/0x1c0 kernel/task_work.c:177
exit_task_work include/linux/task_work.h:38 [inline]
do_exit+0x547/0x1ed0 kernel/exit.c:795
do_group_exit+0x23b/0x2f0 kernel/exit.c:925
__do_sys_exit_group kernel/exit.c:936 [inline]
__se_sys_exit_group kernel/exit.c:934 [inline]
__x64_sys_exit_group+0x3b/0x40 kernel/exit.c:934
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x46/0xb0
RIP: 0033:0x7f934cf16ab9
RSP: 002b:00007fff38b78f88 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 00007f934cf8a330 RCX: 00007f934cf16ab9
RDX: 000000000000003c RSI: 00000000000000e7 RDI: 0000000000000000
RBP: 0000000000000000 R08: ffffffffffffffc0 R09: 0000000000000001
R10: 0000000000000001 R11: 0000000000000246 R12: 00007f934cf8a330
R13: 0000000000000001 R14: 0000000000000000 R15: 0000000000000001
</TASK>
INFO: task syz-executor174:4073 blocked for more than 144 seconds.
Not tainted 5.18.0-syzkaller-10643-g9d004b2f4fea #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor174 state:D stack:26584 pid: 4073 ppid: 3615 flags:0x00004002
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5116 [inline]
__schedule+0x957/0xec0 kernel/sched/core.c:6431
schedule+0xeb/0x1b0 kernel/sched/core.c:6503
schedule_timeout+0xac/0x300 kernel/time/timer.c:1911
do_wait_for_common+0x3ea/0x560 kernel/sched/completion.c:85
__wait_for_common kernel/sched/completion.c:106 [inline]
wait_for_common kernel/sched/completion.c:117 [inline]
wait_for_completion+0x46/0x60 kernel/sched/completion.c:138
__flush_work kernel/workqueue.c:3075 [inline]
__cancel_work_timer+0x585/0x740 kernel/workqueue.c:3162
hci_dev_close_sync+0x31/0xcc0 net/bluetooth/hci_sync.c:4091
hci_dev_do_close net/bluetooth/hci_core.c:553 [inline]
hci_unregister_dev+0x1b1/0x460 net/bluetooth/hci_core.c:2685
hci_uart_tty_close+0x1a7/0x280 drivers/bluetooth/hci_ldisc.c:548
tty_ldisc_kill drivers/tty/tty_ldisc.c:608 [inline]
tty_ldisc_release+0x23c/0x510 drivers/tty/tty_ldisc.c:776
tty_release_struct+0x27/0xd0 drivers/tty/tty_io.c:1694
tty_release+0xc06/0xe60 drivers/tty/tty_io.c:1865
__fput+0x3b9/0x820 fs/file_table.c:317
task_work_run+0x146/0x1c0 kernel/task_work.c:177
exit_task_work include/linux/task_work.h:38 [inline]
do_exit+0x547/0x1ed0 kernel/exit.c:795
do_group_exit+0x23b/0x2f0 kernel/exit.c:925
__do_sys_exit_group kernel/exit.c:936 [inline]
__se_sys_exit_group kernel/exit.c:934 [inline]
__x64_sys_exit_group+0x3b/0x40 kernel/exit.c:934
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x46/0xb0
RIP: 0033:0x7f934cf16ab9
RSP: 002b:00007fff38b78f88 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 00007f934cf8a330 RCX: 00007f934cf16ab9
RDX: 000000000000003c RSI: 00000000000000e7 RDI: 0000000000000000
RBP: 0000000000000000 R08: ffffffffffffffc0 R09: 0000000000000001
R10: 0000000000000001 R11: 0000000000000246 R12: 00007f934cf8a330
R13: 0000000000000001 R14: 0000000000000000 R15: 0000000000000001
</TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/29:
#0: ffffffff8cb1ebe0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30
3 locks held by kworker/u5:0/47:
#0: ffff88801fdcd938 ((wq_completion)hci2){+.+.}-{0:0}, at: process_one_work+0x796/0xd10 kernel/workqueue.c:2262
#1: ffffc90000b87d00 ((work_completion)(&hdev->power_on)){+.+.}-{0:0}, at: process_one_work+0x7d0/0xd10 kernel/workqueue.c:2264
#2: ffff88801d935048 (&hdev->req_lock){+.+.}-{3:3}, at: hci_dev_do_open net/bluetooth/hci_core.c:480 [inline]
#2: ffff88801d935048 (&hdev->req_lock){+.+.}-{3:3}, at: hci_power_on+0x178/0x650 net/bluetooth/hci_core.c:963
2 locks held by getty/3280:
#0: ffff888025914098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:244
#1: ffffc90002cd62e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6ad/0x1c90 drivers/tty/n_tty.c:2075
3 locks held by kworker/u5:5/3630:
#0: ffff88801a8ed938 ((wq_completion)hci0){+.+.}-{0:0}, at: process_one_work+0x796/0xd10 kernel/workqueue.c:2262
#1: ffffc9000315fd00 ((work_completion)(&hdev->power_on)){+.+.}-{0:0}, at: process_one_work+0x7d0/0xd10 kernel/workqueue.c:2264
#2: ffff88801a7d1048 (&hdev->req_lock){+.+.}-{3:3}, at: hci_dev_do_open net/bluetooth/hci_core.c:480 [inline]
#2: ffff88801a7d1048 (&hdev->req_lock){+.+.}-{3:3}, at: hci_power_on+0x178/0x650 net/bluetooth/hci_core.c:963
3 locks held by kworker/u5:6/3631:
#0: ffff8880772d6138 ((wq_completion)hci4){+.+.}-{0:0}, at: process_one_work+0x796/0xd10 kernel/workqueue.c:2262
#1: ffffc9000316fd00 ((work_completion)(&hdev->power_on)){+.+.}-{0:0}, at: process_one_work+0x7d0/0xd10 kernel/workqueue.c:2264
#2: ffff8880778cd048 (&hdev->req_lock){+.+.}-{3:3}, at: hci_dev_do_open net/bluetooth/hci_core.c:480 [inline]
#2: ffff8880778cd048 (&hdev->req_lock){+.+.}-{3:3}, at: hci_power_on+0x178/0x650 net/bluetooth/hci_core.c:963
2 locks held by kworker/0:4/3634:
#0: ffff888011466538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x796/0xd10 kernel/workqueue.c:2262
#1: ffffc900031afd00 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_one_work+0x7d0/0xd10 kernel/workqueue.c:2264
3 locks held by kworker/u5:7/3652:
#0: ffff88801b1bd938 ((wq_completion)hci5){+.+.}-{0:0}, at: process_one_work+0x796/0xd10 kernel/workqueue.c:2262
#1: ffffc900031efd00 ((work_completion)(&hdev->power_on)){+.+.}-{0:0}, at: process_one_work+0x7d0/0xd10 kernel/workqueue.c:2264
#2: ffff888075651048 (&hdev->req_lock){+.+.}-{3:3}, at: hci_dev_do_open net/bluetooth/hci_core.c:480 [inline]
#2: ffff888075651048 (&hdev->req_lock){+.+.}-{3:3}, at: hci_power_on+0x178/0x650 net/bluetooth/hci_core.c:963
3 locks held by kworker/u5:8/3667:
#0: ffff88807b17b138 ((wq_completion)hci3){+.+.}-{0:0}, at: process_one_work+0x796/0xd10 kernel/workqueue.c:2262
#1: ffffc9000309fd00 ((work_completion)(&hdev->power_on)){+.+.}-{0:0}, at: process_one_work+0x7d0/0xd10 kernel/workqueue.c:2264
#2: ffff88807ae29048 (&hdev->req_lock){+.+.}-{3:3}, at: hci_dev_do_open net/bluetooth/hci_core.c:480 [inline]
#2: ffff88807ae29048 (&hdev->req_lock){+.+.}-{3:3}, at: hci_power_on+0x178/0x650 net/bluetooth/hci_core.c:963
3 locks held by syz-executor174/3932:
#0: ffff88801ec0d098 (&tty->ldisc_sem){++++}-{0:0}, at: __tty_ldisc_lock drivers/tty/tty_ldisc.c:290 [inline]
#0: ffff88801ec0d098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_lock_pair_timeout drivers/tty/tty_ldisc.c:336 [inline]
#0: ffff88801ec0d098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_lock_pair drivers/tty/tty_ldisc.c:367 [inline]
#0: ffff88801ec0d098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_release+0x5b/0x510 drivers/tty/tty_ldisc.c:775
#1: ffff88801ec0e098 (&tty->ldisc_sem/1){+.+.}-{0:0}, at: __tty_ldisc_lock_nested drivers/tty/tty_ldisc.c:296 [inline]
#1: ffff88801ec0e098 (&tty->ldisc_sem/1){+.+.}-{0:0}, at: tty_ldisc_lock_pair_timeout drivers/tty/tty_ldisc.c:338 [inline]
#1: ffff88801ec0e098 (&tty->ldisc_sem/1){+.+.}-{0:0}, at: tty_ldisc_lock_pair drivers/tty/tty_ldisc.c:367 [inline]
#1: ffff88801ec0e098 (&tty->ldisc_sem/1){+.+.}-{0:0}, at: tty_ldisc_release+0x7f/0x510 drivers/tty/tty_ldisc.c:775
#2: ffff88801d935048 (&hdev->req_lock){+.+.}-{3:3}, at: hci_dev_do_close net/bluetooth/hci_core.c:551 [inline]
#2: ffff88801d935048 (&hdev->req_lock){+.+.}-{3:3}, at: hci_unregister_dev+0x1a9/0x460 net/bluetooth/hci_core.c:2685
3 locks held by syz-executor174/4073:
#0: ffff888073846098 (&tty->ldisc_sem){++++}-{0:0}, at: __tty_ldisc_lock drivers/tty/tty_ldisc.c:290 [inline]
#0: ffff888073846098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_lock_pair_timeout drivers/tty/tty_ldisc.c:346 [inline]
#0: ffff888073846098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_lock_pair drivers/tty/tty_ldisc.c:367 [inline]
#0: ffff888073846098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_release+0xb3/0x510 drivers/tty/tty_ldisc.c:775
#1: ffff88807d590098 (&tty->ldisc_sem/1){+.+.}-{0:0}, at: __tty_ldisc_lock_nested drivers/tty/tty_ldisc.c:296 [inline]
#1: ffff88807d590098 (&tty->ldisc_sem/1){+.+.}-{0:0}, at: tty_ldisc_lock_pair_timeout drivers/tty/tty_ldisc.c:348 [inline]
#1: ffff88807d590098 (&tty->ldisc_sem/1){+.+.}-{0:0}, at: tty_ldisc_lock_pair drivers/tty/tty_ldisc.c:367 [inline]
#1: ffff88807d590098 (&tty->ldisc_sem/1){+.+.}-{0:0}, at: tty_ldisc_release+0xd7/0x510 drivers/tty/tty_ldisc.c:775
#2: ffff88807ae29048 (&hdev->req_lock){+.+.}-{3:3}, at: hci_dev_do_close net/bluetooth/hci_core.c:551 [inline]
#2: ffff88807ae29048 (&hdev->req_lock){+.+.}-{3:3}, at: hci_unregister_dev+0x1a9/0x460 net/bluetooth/hci_core.c:2685
3 locks held by syz-executor174/4621:
#0: ffff888074f58098 (&tty->ldisc_sem){++++}-{0:0}, at: __tty_ldisc_lock drivers/tty/tty_ldisc.c:290 [inline]
#0: ffff888074f58098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_lock_pair_timeout drivers/tty/tty_ldisc.c:336 [inline]
#0: ffff888074f58098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_lock_pair drivers/tty/tty_ldisc.c:367 [inline]
#0: ffff888074f58098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_release+0x5b/0x510 drivers/tty/tty_ldisc.c:775
#1: ffff888074f5a098 (&tty->ldisc_sem/1){+.+.}-{0:0}, at: __tty_ldisc_lock_nested drivers/tty/tty_ldisc.c:296 [inline]
#1: ffff888074f5a098 (&tty->ldisc_sem/1){+.+.}-{0:0}, at: tty_ldisc_lock_pair_timeout drivers/tty/tty_ldisc.c:338 [inline]
#1: ffff888074f5a098 (&tty->ldisc_sem/1){+.+.}-{0:0}, at: tty_ldisc_lock_pair drivers/tty/tty_ldisc.c:367 [inline]
#1: ffff888074f5a098 (&tty->ldisc_sem/1){+.+.}-{0:0}, at: tty_ldisc_release+0x7f/0x510 drivers/tty/tty_ldisc.c:775
#2: ffff888075651048
(&hdev->req_lock){+.+.}-{3:3}, at: __debug_check_no_obj_freed lib/debugobjects.c:977 [inline]
(&hdev->req_lock){+.+.}-{3:3}, at: debug_check_no_obj_freed+0xc5/0x650 lib/debugobjects.c:1020
3 locks held by syz-executor174/4623:
#0: ffff888021031098 (&tty->ldisc_sem){++++}-{0:0}, at: __tty_ldisc_lock drivers/tty/tty_ldisc.c:290 [inline]
#0: ffff888021031098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_lock_pair_timeout drivers/tty/tty_ldisc.c:346 [inline]
#0: ffff888021031098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_lock_pair drivers/tty/tty_ldisc.c:367 [inline]
#0: ffff888021031098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_release+0xb3/0x510 drivers/tty/tty_ldisc.c:775
#1: ffff888021034098 (&tty->ldisc_sem/1){+.+.}-{0:0}, at: __tty_ldisc_lock_nested drivers/tty/tty_ldisc.c:296 [inline]
#1: ffff888021034098 (&tty->ldisc_sem/1){+.+.}-{0:0}, at: tty_ldisc_lock_pair_timeout drivers/tty/tty_ldisc.c:348 [inline]
#1: ffff888021034098 (&tty->ldisc_sem/1){+.+.}-{0:0}, at: tty_ldisc_lock_pair drivers/tty/tty_ldisc.c:367 [inline]
#1: ffff888021034098 (&tty->ldisc_sem/1){+.+.}-{0:0}, at: tty_ldisc_release+0xd7/0x510 drivers/tty/tty_ldisc.c:775
#2: ffff88801a7d1048 (&hdev->req_lock){+.+.}-{3:3}, at: hci_dev_do_close net/bluetooth/hci_core.c:551 [inline]
#2: ffff88801a7d1048 (&hdev->req_lock){+.+.}-{3:3}, at: hci_unregister_dev+0x1a9/0x460 net/bluetooth/hci_core.c:2685
3 locks held by syz-executor174/4624:
#0: ffff888074f59098 (&tty->ldisc_sem){++++}-{0:0}, at: __tty_ldisc_lock drivers/tty/tty_ldisc.c:290 [inline]
#0: ffff888074f59098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_lock_pair_timeout drivers/tty/tty_ldisc.c:346 [inline]
#0: ffff888074f59098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_lock_pair drivers/tty/tty_ldisc.c:367 [inline]
#0: ffff888074f59098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_release+0xb3/0x510 drivers/tty/tty_ldisc.c:775
#1: ffff888074f5b098 (&tty->ldisc_sem/1){+.+.}-{0:0}, at: __tty_ldisc_lock_nested drivers/tty/tty_ldisc.c:296 [inline]
#1: ffff888074f5b098 (&tty->ldisc_sem/1){+.+.}-{0:0}, at: tty_ldisc_lock_pair_timeout drivers/tty/tty_ldisc.c:348 [inline]
#1: ffff888074f5b098 (&tty->ldisc_sem/1){+.+.}-{0:0}, at: tty_ldisc_lock_pair drivers/tty/tty_ldisc.c:367 [inline]
#1: ffff888074f5b098 (&tty->ldisc_sem/1){+.+.}-{0:0}, at: tty_ldisc_release+0xd7/0x510 drivers/tty/tty_ldisc.c:775
#2: ffff8880778cd048 (&hdev->req_lock){+.+.}-{3:3}, at: hci_dev_do_close net/bluetooth/hci_core.c:551 [inline]
#2: ffff8880778cd048 (&hdev->req_lock){+.+.}-{3:3}, at: hci_unregister_dev+0x1a9/0x460 net/bluetooth/hci_core.c:2685
4 locks held by syz-executor174/4625:
#0: ffff8880166dc098 (&tty->ldisc_sem){++++}-{0:0}, at: __tty_ldisc_lock drivers/tty/tty_ldisc.c:290 [inline]
#0: ffff8880166dc098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_lock_pair_timeout drivers/tty/tty_ldisc.c:346 [inline]
#0: ffff8880166dc098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_lock_pair drivers/tty/tty_ldisc.c:367 [inline]
#0: ffff8880166dc098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_release+0xb3/0x510 drivers/tty/tty_ldisc.c:775
#1: ffff88801cfda098 (&tty->ldisc_sem/1){+.+.}-{0:0}, at: __tty_ldisc_lock_nested drivers/tty/tty_ldisc.c:296 [inline]
#1: ffff88801cfda098 (&tty->ldisc_sem/1){+.+.}-{0:0}, at: tty_ldisc_lock_pair_timeout drivers/tty/tty_ldisc.c:348 [inline]
#1: ffff88801cfda098 (&tty->ldisc_sem/1){+.+.}-{0:0}, at: tty_ldisc_lock_pair drivers/tty/tty_ldisc.c:367 [inline]
#1: ffff88801cfda098 (&tty->ldisc_sem/1){+.+.}-{0:0}, at: tty_ldisc_release+0xd7/0x510 drivers/tty/tty_ldisc.c:775
#2: ffff888023a8f990 (&hu->proto_lock){++++}-{0:0}, at: hci_uart_tty_close+0x123/0x280 drivers/bluetooth/hci_ldisc.c:539
#3: ffffffff8cb23ce0 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:290 [inline]
#3: ffffffff8cb23ce0 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x266/0x720 kernel/rcu/tree_exp.h:927
3 locks held by syz-executor174/4626:
#0: ffff888074220098 (&tty->ldisc_sem){++++}-{0:0}, at: __tty_ldisc_lock drivers/tty/tty_ldisc.c:290 [inline]
#0: ffff888074220098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_lock_pair_timeout drivers/tty/tty_ldisc.c:346 [inline]
#0: ffff888074220098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_lock_pair drivers/tty/tty_ldisc.c:367 [inline]
#0: ffff888074220098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_release+0xb3/0x510 drivers/tty/tty_ldisc.c:775
#1: ffff888074224098 (&tty->ldisc_sem/1){+.+.}-{0:0}, at: __tty_ldisc_lock_nested drivers/tty/tty_ldisc.c:296 [inline]
#1: ffff888074224098 (&tty->ldisc_sem/1){+.+.}-{0:0}, at: tty_ldisc_lock_pair_timeout drivers/tty/tty_ldisc.c:348 [inline]
#1: ffff888074224098 (&tty->ldisc_sem/1){+.+.}-{0:0}, at: tty_ldisc_lock_pair drivers/tty/tty_ldisc.c:367 [inline]
#1: ffff888074224098 (&tty->ldisc_sem/1){+.+.}-{0:0}, at: tty_ldisc_release+0xd7/0x510 drivers/tty/tty_ldisc.c:775
#2: ffff88801f204d90 (&hu->proto_lock){++++}-{0:0}, at: hci_uart_tty_close+0x123/0x280 drivers/bluetooth/hci_ldisc.c:539

=============================================

NMI backtrace for cpu 0
CPU: 0 PID: 29 Comm: khungtaskd Not tainted 5.18.0-syzkaller-10643-g9d004b2f4fea #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106
nmi_cpu_backtrace+0x473/0x4a0 lib/nmi_backtrace.c:111
nmi_trigger_cpumask_backtrace+0x168/0x280 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:220 [inline]
watchdog+0xd18/0xd60 kernel/hung_task.c:378
kthread+0x266/0x300 kernel/kthread.c:376
ret_from_fork+0x1f/0x30
</TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 48 Comm: kworker/u4:2 Not tainted 5.18.0-syzkaller-10643-g9d004b2f4fea #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: events_unbound toggle_allocation_gate
RIP: 0010:get_current arch/x86/include/asm/current.h:15 [inline]
RIP: 0010:__sanitizer_cov_trace_pc+0x4/0x60 kernel/kcov.c:199
Code: 00 00 00 00 66 90 53 48 89 fb e8 17 00 00 00 48 8b 3d 18 f1 7b 0c 48 89 de 5b e9 47 ee 51 00 cc cc cc cc cc cc cc 48 8b 04 24 <65> 48 8b 0c 25 00 6f 02 00 65 8b 15 a4 fc 7a 7e f7 c2 00 01 ff 00
RSP: 0018:ffffc90000b97658 EFLAGS: 00000093
RAX: ffffffff813cd4d4 RBX: ffff8881c00fb000 RCX: 0000000000000000
RDX: ffff8880171ad880 RSI: 000000000000002e RDI: 0000000000000040
RBP: ffffc90000b97790 R08: ffffffff813cd4c5 R09: ffffed1027fc5085
R10: ffffed1027fc5085 R11: 1ffff11027fc5084 R12: 0000000000000000
R13: dffffc0000000000 R14: 00000001400fb000 R15: 000000000000002e
FS: 0000000000000000(0000) GS:ffff8880b9b00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f934cf8b1d0 CR3: 000000000c88e000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
phys_addr_valid arch/x86/mm/physaddr.h:7 [inline]
__phys_addr+0x94/0x160 arch/x86/mm/physaddr.c:28
build_cr3 arch/x86/mm/tlb.c:163 [inline]
load_new_mm_cr3 arch/x86/mm/tlb.c:283 [inline]
switch_mm_irqs_off+0x8f5/0x910 arch/x86/mm/tlb.c:628
use_temporary_mm arch/x86/kernel/alternative.c:962 [inline]
__text_poke+0x5c2/0x9d0 arch/x86/kernel/alternative.c:1073
text_poke arch/x86/kernel/alternative.c:1137 [inline]
text_poke_bp_batch+0x6bc/0x970 arch/x86/kernel/alternative.c:1483
text_poke_flush arch/x86/kernel/alternative.c:1589 [inline]
text_poke_finish+0x16/0x30 arch/x86/kernel/alternative.c:1596
arch_jump_label_transform_apply+0x13/0x20 arch/x86/kernel/jump_label.c:146
static_key_enable_cpuslocked+0x129/0x250 kernel/jump_label.c:177
static_key_enable+0x16/0x20 kernel/jump_label.c:190
toggle_allocation_gate+0xbf/0x470 mm/kfence/core.c:808
process_one_work+0x81c/0xd10 kernel/workqueue.c:2289
worker_thread+0xb14/0x1330 kernel/workqueue.c:2436
kthread+0x266/0x300 kernel/kthread.c:376
ret_from_fork+0x1f/0x30
</TASK>
----------------
Code disassembly (best guess):
0: 00 00 add %al,(%rax)
2: 00 00 add %al,(%rax)
4: 66 90 xchg %ax,%ax
6: 53 push %rbx
7: 48 89 fb mov %rdi,%rbx
a: e8 17 00 00 00 callq 0x26
f: 48 8b 3d 18 f1 7b 0c mov 0xc7bf118(%rip),%rdi # 0xc7bf12e
16: 48 89 de mov %rbx,%rsi
19: 5b pop %rbx
1a: e9 47 ee 51 00 jmpq 0x51ee66
1f: cc int3
20: cc int3
21: cc int3
22: cc int3
23: cc int3
24: cc int3
25: cc int3
26: 48 8b 04 24 mov (%rsp),%rax
* 2a: 65 48 8b 0c 25 00 6f mov %gs:0x26f00,%rcx <-- trapping instruction
31: 02 00
33: 65 8b 15 a4 fc 7a 7e mov %gs:0x7e7afca4(%rip),%edx # 0x7e7afcde
3a: f7 c2 00 01 ff 00 test $0xff0100,%edx


---
This report is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzk...@googlegroups.com.

syzbot will keep track of this issue. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
syzbot can test patches for this issue, for details see:
https://goo.gl/tpsmEJ#testing-patches

[Hillf Danton]

On Wed, 01 Jun 2022 22:28:20 -0700

See if it is due to ff7f2926114d

#syz test https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git 9d004b2f4fea

--- y/net/bluetooth/hci_core.c
+++ x/net/bluetooth/hci_core.c
@@ -2675,6 +2675,7 @@ void hci_unregister_dev(struct hci_dev *
list_del(&hdev->list);
write_unlock(&hci_dev_list_lock);

+ cancel_work_sync(&hdev->power_on);
hci_cmd_sync_clear(hdev);

if (!test_bit(HCI_QUIRK_NO_SUSPEND_NOTIFIER, &hdev->quirks))
--- y/net/bluetooth/hci_sync.c
+++ x/net/bluetooth/hci_sync.c
@@ -2675,6 +2675,7 @@ void hci_unregister_dev(struct hci_dev *
list_del(&hdev->list);
write_unlock(&hci_dev_list_lock);

+ cancel_work_sync(&hdev->power_on);
hci_cmd_sync_clear(hdev);

if (!test_bit(HCI_QUIRK_NO_SUSPEND_NOTIFIER, &hdev->quirks))
--

[syzbot]

Hello,

syzbot tried to test the proposed patch but the build/boot failed:

failed to apply patch:
checking file net/bluetooth/hci_core.c
checking file net/bluetooth/hci_sync.c
Hunk #1 FAILED at 2675.
1 out of 1 hunk FAILED



Tested on:

commit: 9d004b2f Merge tag 'cxl-for-5.19' of git://git.kernel...
git tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git

dashboard link: https://syzkaller.appspot.com/bug?extid=8d7b9ced2a99394b0a50
compiler:

patch: https://syzkaller.appspot.com/x/patch.diff?x=16f9bfedf00000

[Hillf Danton]

On Wed, 01 Jun 2022 22:28:20 -0700

See if it is due to ff7f2926114d

#syz test https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git 9d004b2f4fea

--- y/net/bluetooth/hci_core.c
+++ x/net/bluetooth/hci_core.c
@@ -2675,6 +2675,7 @@ void hci_unregister_dev(struct hci_dev *
list_del(&hdev->list);
write_unlock(&hci_dev_list_lock);

+ cancel_work_sync(&hdev->power_on);
hci_cmd_sync_clear(hdev);

if (!test_bit(HCI_QUIRK_NO_SUSPEND_NOTIFIER, &hdev->quirks))
--- y/net/bluetooth/hci_sync.c
+++ x/net/bluetooth/hci_sync.c

@@ -4088,7 +4088,6 @@ int hci_dev_close_sync(struct hci_dev *h

bt_dev_dbg(hdev, "");

- cancel_work_sync(&hdev->power_on);
cancel_delayed_work(&hdev->power_off);
cancel_delayed_work(&hdev->ncmd_timer);

--

[syzbot]

Hello,

syzbot has tested the proposed patch but the reproducer is still triggering an issue:
KASAN: use-after-free Read in hci_cmd_timeout

==================================================================
BUG: KASAN: use-after-free in hci_cmd_timeout+0x68/0x1e0 net/bluetooth/hci_core.c:1473
Read of size 8 at addr ffff88801a28d358 by task kworker/1:7/4369

CPU: 1 PID: 4369 Comm: kworker/1:7 Not tainted 5.18.0-syzkaller-10643-g9d004b2f4fea-dirty #0

Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011

Workqueue: events hci_cmd_timeout

Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106

print_address_description+0x65/0x4b0 mm/kasan/report.c:313
print_report+0xf4/0x210 mm/kasan/report.c:429
kasan_report+0xfb/0x130 mm/kasan/report.c:491
hci_cmd_timeout+0x68/0x1e0 net/bluetooth/hci_core.c:1473

process_one_work+0x81c/0xd10 kernel/workqueue.c:2289
worker_thread+0xb14/0x1330 kernel/workqueue.c:2436
kthread+0x266/0x300 kernel/kthread.c:376
ret_from_fork+0x1f/0x30
</TASK>

Allocated by task 3611:
kasan_save_stack mm/kasan/common.c:38 [inline]
kasan_set_track mm/kasan/common.c:45 [inline]
set_alloc_info mm/kasan/common.c:436 [inline]
__kasan_slab_alloc+0xb2/0xe0 mm/kasan/common.c:469
kasan_slab_alloc include/linux/kasan.h:224 [inline]
slab_post_alloc_hook mm/slab.h:750 [inline]
slab_alloc_node mm/slub.c:3214 [inline]
slab_alloc mm/slub.c:3222 [inline]
__kmem_cache_alloc_lru mm/slub.c:3229 [inline]
kmem_cache_alloc+0x199/0x2f0 mm/slub.c:3239
skb_clone+0x1aa/0x370 net/core/skbuff.c:1515
hci_cmd_work+0xbc/0x360 net/bluetooth/hci_core.c:3854

process_one_work+0x81c/0xd10 kernel/workqueue.c:2289
worker_thread+0xb14/0x1330 kernel/workqueue.c:2436
kthread+0x266/0x300 kernel/kthread.c:376
ret_from_fork+0x1f/0x30

Freed by task 4083:
kasan_save_stack mm/kasan/common.c:38 [inline]
kasan_set_track+0x4c/0x70 mm/kasan/common.c:45
kasan_set_free_info+0x1f/0x40 mm/kasan/generic.c:370
____kasan_slab_free+0xd8/0x110 mm/kasan/common.c:366
kasan_slab_free include/linux/kasan.h:200 [inline]
slab_free_hook mm/slub.c:1727 [inline]
slab_free_freelist_hook+0x12e/0x1a0 mm/slub.c:1753
slab_free mm/slub.c:3507 [inline]
kmem_cache_free+0xc7/0x270 mm/slub.c:3524
kfree_skb include/linux/skbuff.h:1375 [inline]
hci_dev_open_sync+0x107e/0x1340 net/bluetooth/hci_sync.c:4052
hci_dev_do_open net/bluetooth/hci_core.c:482 [inline]
hci_power_on+0x180/0x650 net/bluetooth/hci_core.c:963

process_one_work+0x81c/0xd10 kernel/workqueue.c:2289
worker_thread+0xb14/0x1330 kernel/workqueue.c:2436
kthread+0x266/0x300 kernel/kthread.c:376
ret_from_fork+0x1f/0x30

The buggy address belongs to the object at ffff88801a28d280
which belongs to the cache skbuff_head_cache of size 240
The buggy address is located 216 bytes inside of
240-byte region [ffff88801a28d280, ffff88801a28d370)

The buggy address belongs to the physical page:
page:ffffea000068a340 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x1a28d
flags: 0xfff00000000200(slab|node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000000200 ffffea0000682640 dead000000000005 ffff888140a57500
raw: 0000000000000000 00000000000c000c 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 51, tgid 51 (kworker/u4:2), ts 58236376345, free_ts 58226454515
prep_new_page mm/page_alloc.c:2456 [inline]
get_page_from_freelist+0x72b/0x7a0 mm/page_alloc.c:4198
__alloc_pages+0x259/0x560 mm/page_alloc.c:5426
alloc_slab_page+0x70/0xf0 mm/slub.c:1797
allocate_slab+0x5e/0x520 mm/slub.c:1942
new_slab mm/slub.c:2002 [inline]
___slab_alloc+0x41e/0xcd0 mm/slub.c:3002
__slab_alloc mm/slub.c:3089 [inline]
slab_alloc_node mm/slub.c:3180 [inline]
kmem_cache_alloc_node+0x287/0x340 mm/slub.c:3264
__alloc_skb+0xd5/0x660 net/core/skbuff.c:414
alloc_skb include/linux/skbuff.h:1426 [inline]
nlmsg_new include/net/netlink.h:953 [inline]
inet6_netconf_notify_devconf+0xf8/0x1b0 net/ipv6/addrconf.c:581
__addrconf_sysctl_unregister net/ipv6/addrconf.c:7112 [inline]
addrconf_sysctl_unregister net/ipv6/addrconf.c:7136 [inline]
addrconf_ifdown+0x18a2/0x1bc0 net/ipv6/addrconf.c:3903
addrconf_notify+0x403/0xf80
notifier_call_chain kernel/notifier.c:84 [inline]
raw_notifier_call_chain+0xe7/0x170 kernel/notifier.c:392
call_netdevice_notifiers_info net/core/dev.c:1943 [inline]
call_netdevice_notifiers_extack net/core/dev.c:1981 [inline]
call_netdevice_notifiers net/core/dev.c:1995 [inline]
unregister_netdevice_many+0xeee/0x1950 net/core/dev.c:10834
default_device_exit_batch+0x660/0x6d0 net/core/dev.c:11328
ops_exit_list net/core/net_namespace.c:167 [inline]
cleanup_net+0x80c/0xc50 net/core/net_namespace.c:594

process_one_work+0x81c/0xd10 kernel/workqueue.c:2289
worker_thread+0xb14/0x1330 kernel/workqueue.c:2436

page last free stack trace:
reset_page_owner include/linux/page_owner.h:24 [inline]
free_pages_prepare mm/page_alloc.c:1371 [inline]
free_pcp_prepare+0x812/0x900 mm/page_alloc.c:1421
free_unref_page_prepare mm/page_alloc.c:3343 [inline]
free_unref_page+0x7d/0x390 mm/page_alloc.c:3438
mm_free_pgd kernel/fork.c:737 [inline]
__mmdrop+0xae/0x3f0 kernel/fork.c:788
mmdrop include/linux/sched/mm.h:50 [inline]
mmdrop_sched include/linux/sched/mm.h:78 [inline]
finish_task_switch+0x221/0x610 kernel/sched/core.c:5021
context_switch kernel/sched/core.c:5119 [inline]
__schedule+0x95f/0xec0 kernel/sched/core.c:6431
schedule+0xeb/0x1b0 kernel/sched/core.c:6503
do_wait+0x7a4/0x9d0 kernel/exit.c:1537
kernel_wait4+0x29c/0x3e0 kernel/exit.c:1681
__do_sys_wait4 kernel/exit.c:1709 [inline]
__se_sys_wait4 kernel/exit.c:1705 [inline]
__x64_sys_wait4+0x130/0x1e0 kernel/exit.c:1705

do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x46/0xb0

Memory state around the buggy address:
ffff88801a28d200: fb fb fb fb fb fb fc fc fc fc fc fc fc fc fc fc
ffff88801a28d280: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff88801a28d300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fc fc
^
ffff88801a28d380: fc fc fc fc fc fc fc fc fa fb fb fb fb fb fb fb
ffff88801a28d400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================


Tested on:

commit: 9d004b2f Merge tag 'cxl-for-5.19' of git://git.kernel...
git tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
console output: https://syzkaller.appspot.com/x/log.txt?x=11b24b8ff00000

kernel config: https://syzkaller.appspot.com/x/.config?x=3c367f7c347f1679
dashboard link: https://syzkaller.appspot.com/bug?extid=8d7b9ced2a99394b0a50
compiler: Debian clang version 13.0.1-++20220126092033+75e33f71c2da-1~exp1~20220126212112.63, GNU ld (GNU Binutils for Debian) 2.35.2

patch: https://syzkaller.appspot.com/x/patch.diff?x=11b72613f00000

[Hillf Danton]

On Thu, 02 Jun 2022 01:41:08 -0700

v1, see if it is due to ff7f2926114d
v2, cancel cmd timeout work before freeing skb in failure of
initilizing hdev.

#syz test https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git 9d004b2f4fea

--- y/net/bluetooth/hci_core.c
+++ x/net/bluetooth/hci_core.c
@@ -2675,6 +2675,7 @@ void hci_unregister_dev(struct hci_dev *
list_del(&hdev->list);
write_unlock(&hci_dev_list_lock);

+ cancel_work_sync(&hdev->power_on);
hci_cmd_sync_clear(hdev);

if (!test_bit(HCI_QUIRK_NO_SUSPEND_NOTIFIER, &hdev->quirks))
--- y/net/bluetooth/hci_sync.c
+++ x/net/bluetooth/hci_sync.c

@@ -4049,6 +4049,7 @@ setup_failed:
hdev->flush(hdev);

if (hdev->sent_cmd) {
+ cancel_delayed_work_sync(&hdev->cmd_timer);
kfree_skb(hdev->sent_cmd);
hdev->sent_cmd = NULL;
}
@@ -4088,7 +4089,6 @@ int hci_dev_close_sync(struct hci_dev *h

[syzbot]

Hello,

syzbot has tested the proposed patch and the reproducer did not trigger any issue:

Reported-and-tested-by: syzbot+8d7b9c...@syzkaller.appspotmail.com

Tested on:

commit: 9d004b2f Merge tag 'cxl-for-5.19' of git://git.kernel...
git tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git

kernel config: https://syzkaller.appspot.com/x/.config?x=3c367f7c347f1679
dashboard link: https://syzkaller.appspot.com/bug?extid=8d7b9ced2a99394b0a50
compiler: Debian clang version 13.0.1-++20220126092033+75e33f71c2da-1~exp1~20220126212112.63, GNU ld (GNU Binutils for Debian) 2.35.2

patch: https://syzkaller.appspot.com/x/patch.diff?x=1645eedbf00000

Note: testing is done by a robot and is best-effort only.

[Siddh Raman Pant]

Hello Hillif,

I had encountered and was looking at how to fix the UAF bug, but didn't see this

google groups page where you had tested a patch.

I have also tested this patch and the UAF no longer occurs (at least for the time

I ran, which would have typically resulted in a crash earlier).

Please send the patch to the kernel mailing list.

Thanks,

Siddh

[syzbot]

syzbot has bisected this issue to:

commit d0b137062b2de75b264b84143d21c98abc5f5ad2
Author: Luiz Augusto von Dentz <luiz.vo...@intel.com>
Date: Wed Oct 27 23:58:59 2021 +0000

Bluetooth: hci_sync: Rework init stages

bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=1674ba1ff00000
start commit: 9d004b2f4fea Merge tag 'cxl-for-5.19' of git://git.kernel...
git tree: upstream
final oops: https://syzkaller.appspot.com/x/report.txt?x=1574ba1ff00000
console output: https://syzkaller.appspot.com/x/log.txt?x=1174ba1ff00000

kernel config: https://syzkaller.appspot.com/x/.config?x=3c367f7c347f1679
dashboard link: https://syzkaller.appspot.com/bug?extid=8d7b9ced2a99394b0a50

syz repro: https://syzkaller.appspot.com/x/repro.syz?x=103f3755f00000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=17f4cf3df00000

Reported-by: syzbot+8d7b9c...@syzkaller.appspotmail.com
Fixes: d0b137062b2d ("Bluetooth: hci_sync: Rework init stages")

For information about bisection process see: https://goo.gl/tpsmEJ#bisection

[syzbot]

Auto-closing this bug as obsolete.
No recent activity, existing reproducers are no longer triggering the issue.