[syzbot] INFO: task hung in hci_dev_close_sync

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 9f9b9a2972eb Add linux-next specific files for 20220502
git tree: linux-next
console output: https://syzkaller.appspot.com/x/log.txt?x=1304f300f00000
kernel config: https://syzkaller.appspot.com/x/.config?x=db7d696bedca61f5
dashboard link: https://syzkaller.appspot.com/bug?extid=c56f6371c48cad0420f9
compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2

Unfortunately, I don't have any reproducer for this issue yet.

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+c56f63...@syzkaller.appspotmail.com

INFO: task kworker/u5:1:3691 blocked for more than 143 seconds.
Not tainted 5.18.0-rc5-next-20220502-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u5:1 state:D stack:27464 pid: 3691 ppid: 2 flags:0x00004000
Workqueue: hci4 hci_power_on
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5106 [inline]
__schedule+0xa9a/0x4cc0 kernel/sched/core.c:6421
schedule+0xd2/0x1f0 kernel/sched/core.c:6493
schedule_timeout+0x1db/0x2a0 kernel/time/timer.c:1883
do_wait_for_common kernel/sched/completion.c:85 [inline]
__wait_for_common+0x378/0x530 kernel/sched/completion.c:106
__flush_work+0x56c/0xb10 kernel/workqueue.c:3098
__cancel_work_timer+0x3f9/0x570 kernel/workqueue.c:3185
hci_dev_close_sync+0x8d/0x1150 net/bluetooth/hci_sync.c:4092
hci_dev_do_close+0x32/0x70 net/bluetooth/hci_core.c:553
hci_power_on+0x1c0/0x630 net/bluetooth/hci_core.c:981
process_one_work+0x996/0x1610 kernel/workqueue.c:2289
worker_thread+0x665/0x1080 kernel/workqueue.c:2436
kthread+0x2e9/0x3a0 kernel/kthread.c:376
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298
</TASK>
INFO: task kworker/u5:2:3694 blocked for more than 143 seconds.
Not tainted 5.18.0-rc5-next-20220502-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u5:2 state:D stack:27688 pid: 3694 ppid: 2 flags:0x00004000
Workqueue: hci1 hci_power_on
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5106 [inline]
__schedule+0xa9a/0x4cc0 kernel/sched/core.c:6421
schedule+0xd2/0x1f0 kernel/sched/core.c:6493
schedule_timeout+0x1db/0x2a0 kernel/time/timer.c:1883
do_wait_for_common kernel/sched/completion.c:85 [inline]
__wait_for_common+0x378/0x530 kernel/sched/completion.c:106
__flush_work+0x56c/0xb10 kernel/workqueue.c:3098
__cancel_work_timer+0x3f9/0x570 kernel/workqueue.c:3185
hci_dev_close_sync+0x8d/0x1150 net/bluetooth/hci_sync.c:4092
hci_dev_do_close+0x32/0x70 net/bluetooth/hci_core.c:553
hci_power_on+0x1c0/0x630 net/bluetooth/hci_core.c:981
process_one_work+0x996/0x1610 kernel/workqueue.c:2289
worker_thread+0x665/0x1080 kernel/workqueue.c:2436
kthread+0x2e9/0x3a0 kernel/kthread.c:376
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298
</TASK>
INFO: task kworker/u5:3:3696 blocked for more than 143 seconds.
Not tainted 5.18.0-rc5-next-20220502-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u5:3 state:D stack:27192 pid: 3696 ppid: 2 flags:0x00004000
Workqueue: hci2 hci_power_on
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5106 [inline]
__schedule+0xa9a/0x4cc0 kernel/sched/core.c:6421
schedule+0xd2/0x1f0 kernel/sched/core.c:6493
schedule_timeout+0x1db/0x2a0 kernel/time/timer.c:1883
do_wait_for_common kernel/sched/completion.c:85 [inline]
__wait_for_common+0x378/0x530 kernel/sched/completion.c:106
__flush_work+0x56c/0xb10 kernel/workqueue.c:3098
__cancel_work_timer+0x3f9/0x570 kernel/workqueue.c:3185
hci_dev_close_sync+0x8d/0x1150 net/bluetooth/hci_sync.c:4092
hci_dev_do_close+0x32/0x70 net/bluetooth/hci_core.c:553
hci_power_on+0x1c0/0x630 net/bluetooth/hci_core.c:981
process_one_work+0x996/0x1610 kernel/workqueue.c:2289
worker_thread+0x665/0x1080 kernel/workqueue.c:2436
kthread+0x2e9/0x3a0 kernel/kthread.c:376
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298
</TASK>
INFO: task kworker/u5:5:5430 blocked for more than 144 seconds.
Not tainted 5.18.0-rc5-next-20220502-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u5:5 state:D stack:27536 pid: 5430 ppid: 2 flags:0x00004000
Workqueue: hci0 hci_power_on
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5106 [inline]
__schedule+0xa9a/0x4cc0 kernel/sched/core.c:6421
schedule+0xd2/0x1f0 kernel/sched/core.c:6493
schedule_timeout+0x1db/0x2a0 kernel/time/timer.c:1883
do_wait_for_common kernel/sched/completion.c:85 [inline]
__wait_for_common+0x378/0x530 kernel/sched/completion.c:106
__flush_work+0x56c/0xb10 kernel/workqueue.c:3098
__cancel_work_timer+0x3f9/0x570 kernel/workqueue.c:3185
hci_dev_close_sync+0x8d/0x1150 net/bluetooth/hci_sync.c:4092
hci_dev_do_close+0x32/0x70 net/bluetooth/hci_core.c:553
hci_power_on+0x1c0/0x630 net/bluetooth/hci_core.c:981
process_one_work+0x996/0x1610 kernel/workqueue.c:2289
worker_thread+0x665/0x1080 kernel/workqueue.c:2436
kthread+0x2e9/0x3a0 kernel/kthread.c:376
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298
</TASK>
INFO: task syz-executor.5:5786 blocked for more than 144 seconds.
Not tainted 5.18.0-rc5-next-20220502-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor.5 state:D stack:28408 pid: 5786 ppid: 1 flags:0x00000000
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5106 [inline]
__schedule+0xa9a/0x4cc0 kernel/sched/core.c:6421
schedule+0xd2/0x1f0 kernel/sched/core.c:6493
schedule_timeout+0x1db/0x2a0 kernel/time/timer.c:1883
do_wait_for_common kernel/sched/completion.c:85 [inline]
__wait_for_common+0x378/0x530 kernel/sched/completion.c:106
flush_workqueue+0x44e/0x1440 kernel/workqueue.c:2884
hci_dev_open+0xdb/0x300 net/bluetooth/hci_core.c:526
hci_sock_ioctl+0x62c/0x910 net/bluetooth/hci_sock.c:1027
sock_do_ioctl+0xcc/0x230 net/socket.c:1131
sock_ioctl+0x2f1/0x640 net/socket.c:1248
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:870 [inline]
__se_sys_ioctl fs/ioctl.c:856 [inline]
__x64_sys_ioctl+0x193/0x200 fs/ioctl.c:856
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
RIP: 0033:0x7f13b1488ea7
RSP: 002b:00007ffeca7dc868 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007ffeca7dcf28 RCX: 00007f13b1488ea7
RDX: 0000000000000000 RSI: 00000000400448c9 RDI: 0000000000000003
RBP: 0000000000000003 R08: 00007f13b0bff700 R09: 00007f13b0bff700
R10: 00007f13b0bff9d0 R11: 0000000000000246 R12: 0000000000000003
R13: 00007ffeca7dc9c0 R14: 00007f13b159c9b8 R15: 000000000000000c
</TASK>
INFO: task syz-executor.3:5903 blocked for more than 144 seconds.
Not tainted 5.18.0-rc5-next-20220502-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor.3 state:D stack:28408 pid: 5903 ppid: 1 flags:0x00004000
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5106 [inline]
__schedule+0xa9a/0x4cc0 kernel/sched/core.c:6421
schedule+0xd2/0x1f0 kernel/sched/core.c:6493
schedule_timeout+0x1db/0x2a0 kernel/time/timer.c:1883
do_wait_for_common kernel/sched/completion.c:85 [inline]
__wait_for_common+0x378/0x530 kernel/sched/completion.c:106
flush_workqueue+0x44e/0x1440 kernel/workqueue.c:2884
hci_dev_open+0xdb/0x300 net/bluetooth/hci_core.c:526
hci_sock_ioctl+0x62c/0x910 net/bluetooth/hci_sock.c:1027
sock_do_ioctl+0xcc/0x230 net/socket.c:1131
sock_ioctl+0x2f1/0x640 net/socket.c:1248
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:870 [inline]
__se_sys_ioctl fs/ioctl.c:856 [inline]
__x64_sys_ioctl+0x193/0x200 fs/ioctl.c:856
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
RIP: 0033:0x7ffbbf688ea7
RSP: 002b:00007fffc1092908 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007fffc1092fc8 RCX: 00007ffbbf688ea7
RDX: 0000000000000001 RSI: 00000000400448c9 RDI: 0000000000000003
RBP: 0000000000000003 R08: 00007ffbbedff700 R09: 00007ffbbedff700
R10: 00007ffbbedff9d0 R11: 0000000000000246 R12: 0000000000000003
R13: 00007fffc1092a60 R14: 00007ffbbf79c9b8 R15: 000000000000000c
</TASK>
INFO: task syz-executor.2:6048 blocked for more than 144 seconds.
Not tainted 5.18.0-rc5-next-20220502-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor.2 state:D stack:28408 pid: 6048 ppid: 1 flags:0x00004000
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5106 [inline]
__schedule+0xa9a/0x4cc0 kernel/sched/core.c:6421
schedule+0xd2/0x1f0 kernel/sched/core.c:6493
schedule_timeout+0x1db/0x2a0 kernel/time/timer.c:1883
do_wait_for_common kernel/sched/completion.c:85 [inline]
__wait_for_common+0x378/0x530 kernel/sched/completion.c:106
flush_workqueue+0x44e/0x1440 kernel/workqueue.c:2884
hci_dev_open+0xdb/0x300 net/bluetooth/hci_core.c:526
hci_sock_ioctl+0x62c/0x910 net/bluetooth/hci_sock.c:1027
sock_do_ioctl+0xcc/0x230 net/socket.c:1131
sock_ioctl+0x2f1/0x640 net/socket.c:1248
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:870 [inline]
__se_sys_ioctl fs/ioctl.c:856 [inline]
__x64_sys_ioctl+0x193/0x200 fs/ioctl.c:856
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
RIP: 0033:0x7ff9c0e88ea7
RSP: 002b:00007ffed3e82ed8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007ffed3e83598 RCX: 00007ff9c0e88ea7
RDX: 0000000000000004 RSI: 00000000400448c9 RDI: 0000000000000003
RBP: 0000000000000003 R08: 00007ff9c05ff700 R09: 00007ff9c05ff700
R10: 00007ff9c05ff9d0 R11: 0000000000000246 R12: 0000000000000003
R13: 00007ffed3e83030 R14: 00007ff9c0f9c9b8 R15: 000000000000000c
</TASK>
INFO: task syz-executor.0:6305 blocked for more than 145 seconds.
Not tainted 5.18.0-rc5-next-20220502-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor.0 state:D stack:28408 pid: 6305 ppid: 1 flags:0x00000000
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5106 [inline]
__schedule+0xa9a/0x4cc0 kernel/sched/core.c:6421
schedule+0xd2/0x1f0 kernel/sched/core.c:6493
schedule_timeout+0x1db/0x2a0 kernel/time/timer.c:1883
do_wait_for_common kernel/sched/completion.c:85 [inline]
__wait_for_common+0x378/0x530 kernel/sched/completion.c:106
flush_workqueue+0x44e/0x1440 kernel/workqueue.c:2884
hci_dev_open+0xdb/0x300 net/bluetooth/hci_core.c:526
hci_sock_ioctl+0x62c/0x910 net/bluetooth/hci_sock.c:1027
sock_do_ioctl+0xcc/0x230 net/socket.c:1131
sock_ioctl+0x2f1/0x640 net/socket.c:1248
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:870 [inline]
__se_sys_ioctl fs/ioctl.c:856 [inline]
__x64_sys_ioctl+0x193/0x200 fs/ioctl.c:856
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
RIP: 0033:0x7fe7a4488ea7
RSP: 002b:00007ffcc64117a8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007ffcc6411e68 RCX: 00007fe7a4488ea7
RDX: 0000000000000002 RSI: 00000000400448c9 RDI: 0000000000000003
RBP: 0000000000000003 R08: 00007fe7a3bff700 R09: 00007fe7a3bff700
R10: 00007fe7a3bff9d0 R11: 0000000000000246 R12: 0000000000000003
R13: 00007ffcc6411900 R14: 00007fe7a459c9b8 R15: 000000000000000c
</TASK>

Showing all locks held in the system:
1 lock held by rcu_tasks_kthre/12:
#0: ffffffff8bd84cd0 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x26/0xc70 kernel/rcu/tasks.h:502
1 lock held by rcu_tasks_trace/13:
#0: ffffffff8bd84950 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x26/0xc70 kernel/rcu/tasks.h:502
1 lock held by khungtaskd/29:
#0: ffffffff8bd85820 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:6491
2 locks held by getty/3356:
#0: ffff88814bb09098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:244
#1: ffffc90002ce62e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0xe50/0x13c0 drivers/tty/n_tty.c:2118
3 locks held by kworker/u5:1/3691:
#0: ffff88802520a938 ((wq_completion)hci4){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline]
#0: ffff88802520a938 ((wq_completion)hci4){+.+.}-{0:0}, at: arch_atomic_long_set include/linux/atomic/atomic-long.h:41 [inline]
#0: ffff88802520a938 ((wq_completion)hci4){+.+.}-{0:0}, at: atomic_long_set include/linux/atomic/atomic-instrumented.h:1280 [inline]
#0: ffff88802520a938 ((wq_completion)hci4){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:636 [inline]
#0: ffff88802520a938 ((wq_completion)hci4){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:663 [inline]
#0: ffff88802520a938 ((wq_completion)hci4){+.+.}-{0:0}, at: process_one_work+0x87a/0x1610 kernel/workqueue.c:2260
#1: ffffc90002f5fda8 ((work_completion)(&hdev->power_on)){+.+.}-{0:0}, at: process_one_work+0x8ae/0x1610 kernel/workqueue.c:2264
#2: ffff88801e529048 (&hdev->req_lock){+.+.}-{3:3}, at: hci_dev_do_close+0x2a/0x70 net/bluetooth/hci_core.c:551
3 locks held by kworker/u5:2/3694:
#0: ffff88807eb0f138 ((wq_completion)hci1){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline]
#0: ffff88807eb0f138 ((wq_completion)hci1){+.+.}-{0:0}, at: arch_atomic_long_set include/linux/atomic/atomic-long.h:41 [inline]
#0: ffff88807eb0f138 ((wq_completion)hci1){+.+.}-{0:0}, at: atomic_long_set include/linux/atomic/atomic-instrumented.h:1280 [inline]
#0: ffff88807eb0f138 ((wq_completion)hci1){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:636 [inline]
#0: ffff88807eb0f138 ((wq_completion)hci1){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:663 [inline]
#0: ffff88807eb0f138 ((wq_completion)hci1){+.+.}-{0:0}, at: process_one_work+0x87a/0x1610 kernel/workqueue.c:2260
#1: ffffc9000307fda8 ((work_completion)(&hdev->power_on)){+.+.}-{0:0}, at: process_one_work+0x8ae/0x1610 kernel/workqueue.c:2264
#2: ffff88801e165048 (&hdev->req_lock){+.+.}-{3:3}, at: hci_dev_do_close+0x2a/0x70 net/bluetooth/hci_core.c:551
3 locks held by kworker/u5:3/3696:
#0: ffff88807ad37938 ((wq_completion)hci2){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline]
#0: ffff88807ad37938 ((wq_completion)hci2){+.+.}-{0:0}, at: arch_atomic_long_set include/linux/atomic/atomic-long.h:41 [inline]
#0: ffff88807ad37938 ((wq_completion)hci2){+.+.}-{0:0}, at: atomic_long_set include/linux/atomic/atomic-instrumented.h:1280 [inline]
#0: ffff88807ad37938 ((wq_completion)hci2){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:636 [inline]
#0: ffff88807ad37938 ((wq_completion)hci2){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:663 [inline]
#0: ffff88807ad37938 ((wq_completion)hci2){+.+.}-{0:0}, at: process_one_work+0x87a/0x1610 kernel/workqueue.c:2260
#1: ffffc9000309fda8 ((work_completion)(&hdev->power_on)){+.+.}-{0:0}, at: process_one_work+0x8ae/0x1610 kernel/workqueue.c:2264
#2: ffff88807d985048 (&hdev->req_lock){+.+.}-{3:3}, at: hci_dev_do_close+0x2a/0x70 net/bluetooth/hci_core.c:551
3 locks held by kworker/u5:5/5430:
#0: ffff88805b8c0938 ((wq_completion)hci0){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline]
#0: ffff88805b8c0938 ((wq_completion)hci0){+.+.}-{0:0}, at: arch_atomic_long_set include/linux/atomic/atomic-long.h:41 [inline]
#0: ffff88805b8c0938 ((wq_completion)hci0){+.+.}-{0:0}, at: atomic_long_set include/linux/atomic/atomic-instrumented.h:1280 [inline]
#0: ffff88805b8c0938 ((wq_completion)hci0){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:636 [inline]
#0: ffff88805b8c0938 ((wq_completion)hci0){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:663 [inline]
#0: ffff88805b8c0938 ((wq_completion)hci0){+.+.}-{0:0}, at: process_one_work+0x87a/0x1610 kernel/workqueue.c:2260
#1: ffffc90002e3fda8 ((work_completion)(&hdev->power_on)){+.+.}-{0:0}, at: process_one_work+0x8ae/0x1610 kernel/workqueue.c:2264
#2: ffff888075741048 (&hdev->req_lock){+.+.}-{3:3}, at: hci_dev_do_close+0x2a/0x70 net/bluetooth/hci_core.c:551

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

NMI backtrace for cpu 0
CPU: 0 PID: 29 Comm: khungtaskd Not tainted 5.18.0-rc5-next-20220502-syzkaller #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+0xcd/0x134 lib/dump_stack.c:106
nmi_cpu_backtrace.cold+0x47/0x144 lib/nmi_backtrace.c:111
nmi_trigger_cpumask_backtrace+0x1e6/0x230 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+0xc22/0xf90 kernel/hung_task.c:378
kthread+0x2e9/0x3a0 kernel/kthread.c:376
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298
</TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 8 Comm: kworker/u4:0 Not tainted 5.18.0-rc5-next-20220502-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: events_unbound toggle_allocation_gate
RIP: 0010:__lock_acquire+0xd51/0x5660 kernel/locking/lockdep.c:5063
Code: 03 0f b6 04 02 84 c0 74 0d 3c 03 7f 09 48 8b 3c 24 e8 63 78 69 00 41 8b 85 58 0a 00 00 83 c0 01 83 f8 2f 41 89 85 58 0a 00 00 <0f> 87 eb 0b 00 00 3b 05 53 e2 1e 0e 41 be 01 00 00 00 0f 86 c8 00
RSP: 0018:ffffc900000d7748 EFLAGS: 00000097
RAX: 0000000000000006 RBX: ffffffff8f3c6c00 RCX: ffffffff815ddcee
RDX: 1ffff110021e1c5b RSI: 0000000000000001 RDI: ffffffff8f3c6c18
RBP: 000000000000f5e5 R08: 0000000000000000 R09: ffffffff9007b897
R10: fffffbfff200f712 R11: 0000000000000001 R12: ffff888010f0e3a8
R13: ffff888010f0d880 R14: 0000000000000000 R15: d4985ce4c67f0360
FS: 0000000000000000(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000c001d7d000 CR3: 000000000ba8e000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
lock_acquire kernel/locking/lockdep.c:5665 [inline]
lock_acquire+0x1ab/0x570 kernel/locking/lockdep.c:5630
__raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline]
_raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:154
spin_lock include/linux/spinlock.h:354 [inline]
__get_locked_pte+0x154/0x270 mm/memory.c:1830
get_locked_pte include/linux/mm.h:2127 [inline]
__text_poke+0x1ae/0x8c0 arch/x86/kernel/alternative.c:1038
text_poke arch/x86/kernel/alternative.c:1121 [inline]
text_poke_bp_batch+0x433/0x6b0 arch/x86/kernel/alternative.c:1436
text_poke_flush arch/x86/kernel/alternative.c:1542 [inline]
text_poke_flush arch/x86/kernel/alternative.c:1539 [inline]
text_poke_finish+0x16/0x30 arch/x86/kernel/alternative.c:1549
arch_jump_label_transform_apply+0x13/0x20 arch/x86/kernel/jump_label.c:146
jump_label_update+0x32f/0x410 kernel/jump_label.c:830
static_key_disable_cpuslocked+0x152/0x1b0 kernel/jump_label.c:207
static_key_disable+0x16/0x20 kernel/jump_label.c:215
toggle_allocation_gate mm/kfence/core.c:809 [inline]
toggle_allocation_gate+0x183/0x390 mm/kfence/core.c:787
process_one_work+0x996/0x1610 kernel/workqueue.c:2289
worker_thread+0x665/0x1080 kernel/workqueue.c:2436
kthread+0x2e9/0x3a0 kernel/kthread.c:376
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298
</TASK>
----------------
Code disassembly (best guess):
0: 03 0f add (%rdi),%ecx
2: b6 04 mov $0x4,%dh
4: 02 84 c0 74 0d 3c 03 add 0x33c0d74(%rax,%rax,8),%al
b: 7f 09 jg 0x16
d: 48 8b 3c 24 mov (%rsp),%rdi
11: e8 63 78 69 00 callq 0x697879
16: 41 8b 85 58 0a 00 00 mov 0xa58(%r13),%eax
1d: 83 c0 01 add $0x1,%eax
20: 83 f8 2f cmp $0x2f,%eax
23: 41 89 85 58 0a 00 00 mov %eax,0xa58(%r13)
* 2a: 0f 87 eb 0b 00 00 ja 0xc1b <-- trapping instruction
30: 3b 05 53 e2 1e 0e cmp 0xe1ee253(%rip),%eax # 0xe1ee289
36: 41 be 01 00 00 00 mov $0x1,%r14d
3c: 0f .byte 0xf
3d: 86 c8 xchg %cl,%al


---
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.

[Hillf Danton]

On Tue, 03 May 2022 09:59:16 -0700

This is the problem, see below.

Given the call trace reported,

process_one_work
lock_map_acquire(&pwq->wq->lockdep_map);
lock_map_acquire(&lockdep_map);
hci_power_on
hci_dev_do_close
hci_req_sync_lock(hdev);
hci_dev_close_sync(hdev);
cancel_work_sync(&hdev->power_on);
__cancel_work_timer()
__flush_work(work, true);
if (!from_cancel) {
lock_map_acquire(&work->lockdep_map);
lock_map_release(&work->lockdep_map);
}
hci_req_sync_unlock(hdev);


syzbot should have been able to catch cancel_work_sync() in work context
by checking lockdep_map in __flush_work() for both flush and cancel.

Hillf

--- y/kernel/workqueue.c
+++ x/kernel/workqueue.c
@@ -3075,10 +3075,10 @@ static bool __flush_work(struct work_str
if (WARN_ON(!work->func))
return false;

- if (!from_cancel) {
+ //if (!from_cancel) {
lock_map_acquire(&work->lockdep_map);
lock_map_release(&work->lockdep_map);
- }
+ //}

if (start_flush_work(work, &barr, from_cancel)) {
wait_for_completion(&barr.done);

[Tetsuo Handa]

Hello, Johannes.

This seems to be a question regarding commit 87915adc3f0acdf0 ("workqueue: re-add lockdep dependencies for flushing").

[Johannes Berg]

On Wed, 2022-05-04 at 05:12 +0000, Tetsuo Handa wrote:
>
> This seems to be a question regarding commit 87915adc3f0acdf0 ("workqueue: re-add lockdep dependencies for flushing").
> >

> > syzbot should have been able to catch cancel_work_sync() in work context
> > by checking lockdep_map in __flush_work() for both flush and cancel.
> >
> > Hillf
> >
> > --- y/kernel/workqueue.c
> > +++ x/kernel/workqueue.c
> > @@ -3075,10 +3075,10 @@ static bool __flush_work(struct work_str
> > if (WARN_ON(!work->func))
> > return false;
> >
> > - if (!from_cancel) {
> > + //if (!from_cancel) {
> >

I think this is explained in commit d6e89786bed9 ("workqueue: skip
lockdep wq dependency in cancel_work_sync()")

johannes

[syzbot]

syzbot has found a reproducer for 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=12fe6d23f00000
kernel config: https://syzkaller.appspot.com/x/.config?x=d5ef46f0e355ceff

dashboard link: https://syzkaller.appspot.com/bug?extid=c56f6371c48cad0420f9
compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2

syz repro: https://syzkaller.appspot.com/x/repro.syz?x=17c258f5f00000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=144f1233f00000

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+c56f63...@syzkaller.appspotmail.com

INFO: task kworker/u5:1:3610 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/u5:1 state:D stack:27304 pid: 3610 ppid: 2 flags:0x00004000
Workqueue: hci9 hci_power_on
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5116 [inline]
__schedule+0xa00/0x4b30 kernel/sched/core.c:6431
schedule+0xd2/0x1f0 kernel/sched/core.c:6503
schedule_timeout+0x1db/0x2a0 kernel/time/timer.c:1911

do_wait_for_common kernel/sched/completion.c:85 [inline]
__wait_for_common+0x378/0x530 kernel/sched/completion.c:106

__flush_work+0x56c/0xb10 kernel/workqueue.c:3075
__cancel_work_timer+0x3f9/0x570 kernel/workqueue.c:3162
hci_dev_close_sync+0x8d/0x1150 net/bluetooth/hci_sync.c:4091

hci_dev_do_close+0x32/0x70 net/bluetooth/hci_core.c:553
hci_power_on+0x1c0/0x630 net/bluetooth/hci_core.c:981
process_one_work+0x996/0x1610 kernel/workqueue.c:2289
worker_thread+0x665/0x1080 kernel/workqueue.c:2436
kthread+0x2e9/0x3a0 kernel/kthread.c:376

ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:302
</TASK>
INFO: task kworker/u5:3:3617 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:kworker/u5:3 state:D stack:27568 pid: 3617 ppid: 2 flags:0x00004000
Workqueue: hci8 hci_power_on
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5116 [inline]
__schedule+0xa00/0x4b30 kernel/sched/core.c:6431
schedule+0xd2/0x1f0 kernel/sched/core.c:6503
schedule_timeout+0x1db/0x2a0 kernel/time/timer.c:1911

do_wait_for_common kernel/sched/completion.c:85 [inline]
__wait_for_common+0x378/0x530 kernel/sched/completion.c:106

__flush_work+0x56c/0xb10 kernel/workqueue.c:3075
__cancel_work_timer+0x3f9/0x570 kernel/workqueue.c:3162
hci_dev_close_sync+0x8d/0x1150 net/bluetooth/hci_sync.c:4091

hci_dev_do_close+0x32/0x70 net/bluetooth/hci_core.c:553
hci_power_on+0x1c0/0x630 net/bluetooth/hci_core.c:981
process_one_work+0x996/0x1610 kernel/workqueue.c:2289
worker_thread+0x665/0x1080 kernel/workqueue.c:2436
kthread+0x2e9/0x3a0 kernel/kthread.c:376

ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:302
</TASK>
INFO: task kworker/u5:4:3619 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:kworker/u5:4 state:D stack:27192 pid: 3619 ppid: 2 flags:0x00004000
Workqueue: hci7 hci_power_on
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5116 [inline]
__schedule+0xa00/0x4b30 kernel/sched/core.c:6431
schedule+0xd2/0x1f0 kernel/sched/core.c:6503
schedule_timeout+0x1db/0x2a0 kernel/time/timer.c:1911

do_wait_for_common kernel/sched/completion.c:85 [inline]
__wait_for_common+0x378/0x530 kernel/sched/completion.c:106

__flush_work+0x56c/0xb10 kernel/workqueue.c:3075
__cancel_work_timer+0x3f9/0x570 kernel/workqueue.c:3162
hci_dev_close_sync+0x8d/0x1150 net/bluetooth/hci_sync.c:4091

hci_dev_do_close+0x32/0x70 net/bluetooth/hci_core.c:553
hci_power_on+0x1c0/0x630 net/bluetooth/hci_core.c:981
process_one_work+0x996/0x1610 kernel/workqueue.c:2289
worker_thread+0x665/0x1080 kernel/workqueue.c:2436
kthread+0x2e9/0x3a0 kernel/kthread.c:376

ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:302
</TASK>
INFO: task syz-executor921:3700 blocked for more than 145 seconds.
Not tainted 5.18.0-syzkaller-10643-g9d004b2f4fea #0

"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.

task:syz-executor921 state:D stack:27944 pid: 3700 ppid: 3603 flags:0x00004000
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5116 [inline]
__schedule+0xa00/0x4b30 kernel/sched/core.c:6431
schedule+0xd2/0x1f0 kernel/sched/core.c:6503
schedule_timeout+0x1db/0x2a0 kernel/time/timer.c:1911

do_wait_for_common kernel/sched/completion.c:85 [inline]
__wait_for_common+0x378/0x530 kernel/sched/completion.c:106

flush_workqueue+0x3ed/0x13a0 kernel/workqueue.c:2861

hci_dev_open+0xdb/0x300 net/bluetooth/hci_core.c:526
hci_sock_ioctl+0x62c/0x910 net/bluetooth/hci_sock.c:1027

sock_do_ioctl+0xcc/0x230 net/socket.c:1169
sock_ioctl+0x2f1/0x640 net/socket.c:1286

vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:870 [inline]
__se_sys_ioctl fs/ioctl.c:856 [inline]
__x64_sys_ioctl+0x193/0x200 fs/ioctl.c:856
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+0x46/0xb0
RIP: 0033:0x7f595e7f37e7
RSP: 002b:00007ffc76721138 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007f595e7f37e7
RDX: 0000000000000009 RSI: 00000000400448c9 RDI: 0000000000000003
RBP: 0000000000000004 R08: 00007f595e7a0700 R09: 00007f595e7a0700
R10: 00007f595e7a09d0 R11: 0000000000000246 R12: 6c616b7a79732f2e
R13: 585858582e72656c R14: 00007ffc76721164 R15: 00007ffc767211a0
</TASK>
INFO: task syz-executor921:3701 blocked for more than 145 seconds.
Not tainted 5.18.0-syzkaller-10643-g9d004b2f4fea #0

"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.

task:syz-executor921 state:D stack:27944 pid: 3701 ppid: 3603 flags:0x00004000
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5116 [inline]
__schedule+0xa00/0x4b30 kernel/sched/core.c:6431
schedule+0xd2/0x1f0 kernel/sched/core.c:6503
schedule_timeout+0x1db/0x2a0 kernel/time/timer.c:1911

do_wait_for_common kernel/sched/completion.c:85 [inline]
__wait_for_common+0x378/0x530 kernel/sched/completion.c:106

flush_workqueue+0x3ed/0x13a0 kernel/workqueue.c:2861

hci_dev_open+0xdb/0x300 net/bluetooth/hci_core.c:526
hci_sock_ioctl+0x62c/0x910 net/bluetooth/hci_sock.c:1027

sock_do_ioctl+0xcc/0x230 net/socket.c:1169
sock_ioctl+0x2f1/0x640 net/socket.c:1286

vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:870 [inline]
__se_sys_ioctl fs/ioctl.c:856 [inline]
__x64_sys_ioctl+0x193/0x200 fs/ioctl.c:856
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+0x46/0xb0
RIP: 0033:0x7f595e7f37e7
RSP: 002b:00007ffc76721138 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007f595e7f37e7
RDX: 0000000000000007 RSI: 00000000400448c9 RDI: 0000000000000003
RBP: 0000000000000004 R08: 00007f595e7a0700 R09: 00007f595e7a0700
R10: 00007f595e7a09d0 R11: 0000000000000246 R12: 6c616b7a79732f2e
R13: 585858582e72656c R14: 00007ffc76721164 R15: 00007ffc767211a0
</TASK>
INFO: task syz-executor921:3702 blocked for more than 145 seconds.
Not tainted 5.18.0-syzkaller-10643-g9d004b2f4fea #0

"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.

task:syz-executor921 state:D stack:26648 pid: 3702 ppid: 3603 flags:0x00004000
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5116 [inline]
__schedule+0xa00/0x4b30 kernel/sched/core.c:6431
schedule+0xd2/0x1f0 kernel/sched/core.c:6503
schedule_timeout+0x1db/0x2a0 kernel/time/timer.c:1911

do_wait_for_common kernel/sched/completion.c:85 [inline]
__wait_for_common+0x378/0x530 kernel/sched/completion.c:106

flush_workqueue+0x3ed/0x13a0 kernel/workqueue.c:2861

hci_dev_open+0xdb/0x300 net/bluetooth/hci_core.c:526
hci_sock_ioctl+0x62c/0x910 net/bluetooth/hci_sock.c:1027

sock_do_ioctl+0xcc/0x230 net/socket.c:1169
sock_ioctl+0x2f1/0x640 net/socket.c:1286

vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:870 [inline]
__se_sys_ioctl fs/ioctl.c:856 [inline]
__x64_sys_ioctl+0x193/0x200 fs/ioctl.c:856
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+0x46/0xb0
RIP: 0033:0x7f595e7f37e7
RSP: 002b:00007ffc76721138 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007f595e7f37e7
RDX: 0000000000000008 RSI: 00000000400448c9 RDI: 0000000000000003
RBP: 0000000000000004 R08: 00007f595e7a0700 R09: 00007f595e7a0700
R10: 00007f595e7a09d0 R11: 0000000000000246 R12: 6c616b7a79732f2e
R13: 585858582e72656c R14: 00007ffc76721164 R15: 00007ffc767211a0

</TASK>

Showing all locks held in the system:

1 lock held by khungtaskd/29:
#0: ffffffff8bd86860 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:6491
2 locks held by getty/3285:
#0: ffff88814c09b098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:244
#1: ffffc90002cd62e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0xcea/0x1230 drivers/tty/n_tty.c:2075
2 locks held by sshd/3597:
3 locks held by kworker/u5:1/3610:
#0: ffff88807898c138 ((wq_completion)hci9){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline]
#0: ffff88807898c138 ((wq_completion)hci9){+.+.}-{0:0}, at: arch_atomic_long_set include/linux/atomic/atomic-long.h:41 [inline]
#0: ffff88807898c138 ((wq_completion)hci9){+.+.}-{0:0}, at: atomic_long_set include/linux/atomic/atomic-instrumented.h:1280 [inline]
#0: ffff88807898c138 ((wq_completion)hci9){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:636 [inline]
#0: ffff88807898c138 ((wq_completion)hci9){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:663 [inline]
#0: ffff88807898c138 ((wq_completion)hci9){+.+.}-{0:0}, at: process_one_work+0x87a/0x1610 kernel/workqueue.c:2260
#1: ffffc9000302fda8 ((work_completion)(&hdev->power_on)){+.+.}-{0:0}, at: process_one_work+0x8ae/0x1610 kernel/workqueue.c:2264
#2: ffff88801a3f9048 (&hdev->req_lock){+.+.}-{3:3}, at: hci_dev_do_close+0x2a/0x70 net/bluetooth/hci_core.c:551
3 locks held by kworker/u5:3/3617:
#0: ffff888076411138 ((wq_completion)hci8){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline]
#0: ffff888076411138 ((wq_completion)hci8){+.+.}-{0:0}, at: arch_atomic_long_set include/linux/atomic/atomic-long.h:41 [inline]
#0: ffff888076411138 ((wq_completion)hci8){+.+.}-{0:0}, at: atomic_long_set include/linux/atomic/atomic-instrumented.h:1280 [inline]
#0: ffff888076411138 ((wq_completion)hci8){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:636 [inline]
#0: ffff888076411138 ((wq_completion)hci8){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:663 [inline]
#0: ffff888076411138 ((wq_completion)hci8){+.+.}-{0:0}, at: process_one_work+0x87a/0x1610 kernel/workqueue.c:2260
#1: ffffc9000312fda8 ((work_completion)(&hdev->power_on)){+.+.}-{0:0}, at: process_one_work+0x8ae/0x1610 kernel/workqueue.c:2264
#2: ffff88807421d048 (&hdev->req_lock){+.+.}-{3:3}, at: hci_dev_do_close+0x2a/0x70 net/bluetooth/hci_core.c:551
3 locks held by kworker/u5:4/3619:
#0: ffff888076414138 ((wq_completion)hci7){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline]
#0: ffff888076414138 ((wq_completion)hci7){+.+.}-{0:0}, at: arch_atomic_long_set include/linux/atomic/atomic-long.h:41 [inline]
#0: ffff888076414138 ((wq_completion)hci7){+.+.}-{0:0}, at: atomic_long_set include/linux/atomic/atomic-instrumented.h:1280 [inline]
#0: ffff888076414138 ((wq_completion)hci7){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:636 [inline]
#0: ffff888076414138 ((wq_completion)hci7){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:663 [inline]
#0: ffff888076414138 ((wq_completion)hci7){+.+.}-{0:0}, at: process_one_work+0x87a/0x1610 kernel/workqueue.c:2260
#1: ffffc9000315fda8 ((work_completion)(&hdev->power_on)){+.+.}-{0:0}, at: process_one_work+0x8ae/0x1610 kernel/workqueue.c:2264
#2: ffff888074219048 (&hdev->req_lock){+.+.}-{3:3}, at: hci_dev_do_close+0x2a/0x70 net/bluetooth/hci_core.c:551

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

NMI backtrace for cpu 1
CPU: 1 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+0xcd/0x134 lib/dump_stack.c:106
nmi_cpu_backtrace.cold+0x47/0x144 lib/nmi_backtrace.c:111
nmi_trigger_cpumask_backtrace+0x1e6/0x230 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+0xc22/0xf90 kernel/hung_task.c:378
kthread+0x2e9/0x3a0 kernel/kthread.c:376

ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:302
</TASK>
Sending NMI from CPU 1 to CPUs 0:

NMI backtrace for cpu 0

CPU: 0 PID: 3599 Comm: strace-static-x Not tainted 5.18.0-syzkaller-10643-g9d004b2f4fea #0

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

RIP: 0010:memory_is_poisoned_n mm/kasan/generic.c:129 [inline]
RIP: 0010:memory_is_poisoned mm/kasan/generic.c:159 [inline]
RIP: 0010:check_region_inline mm/kasan/generic.c:180 [inline]
RIP: 0010:kasan_check_range+0x55/0x180 mm/kasan/generic.c:189
Code: 86 05 01 00 00 49 83 e9 01 48 89 fd 48 b8 00 00 00 00 00 fc ff df 4d 89 ca 48 c1 ed 03 49 c1 ea 03 48 01 c5 49 01 c2 48 89 e8 <49> 8d 5a 01 48 89 da 48 29 ea 48 83 fa 10 7e 63 41 89 eb 41 83 e3
RSP: 0018:ffffc90002eff9c8 EFLAGS: 00000082
RAX: fffffbfff1b77492 RBX: 0000000000000000 RCX: ffffffff815e5141
RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff8dbba490
RBP: fffffbfff1b77492 R08: 0000000000000000 R09: ffffffff8dbba497
R10: fffffbfff1b77492 R11: 0000000000000000 R12: ffff8880b9c39ed8
R13: ffff8880b9c39ec0 R14: ffff88802525a298 R15: ffff888025259d80
FS: 0000000000757340(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000

CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033

CR2: 00005555566c1608 CR3: 0000000073fd2000 CR4: 00000000003506f0

DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>

instrument_atomic_read include/linux/instrumented.h:71 [inline]
test_bit include/asm-generic/bitops/instrumented-non-atomic.h:134 [inline]
cpumask_test_cpu include/linux/cpumask.h:379 [inline]
cpu_online include/linux/cpumask.h:921 [inline]
trace_lock_release include/trace/events/lock.h:69 [inline]
lock_release+0xa1/0x780 kernel/locking/lockdep.c:5676
prepare_lock_switch kernel/sched/core.c:4860 [inline]
context_switch kernel/sched/core.c:5113 [inline]
__schedule+0x9cd/0x4b30 kernel/sched/core.c:6431
preempt_schedule_common+0x45/0xc0 kernel/sched/core.c:6596
preempt_schedule_thunk+0x16/0x18 arch/x86/entry/thunk_64.S:35
try_to_wake_up+0xa04/0x1800 kernel/sched/core.c:4201
ptrace_resume+0x27d/0x2d0 kernel/ptrace.c:895
ptrace_request+0x180/0xef0 kernel/ptrace.c:1230
arch_ptrace+0x36/0x510 arch/x86/kernel/ptrace.c:828
__do_sys_ptrace kernel/ptrace.c:1321 [inline]
__se_sys_ptrace kernel/ptrace.c:1286 [inline]
__x64_sys_ptrace+0x178/0x310 kernel/ptrace.c:1286

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+0x46/0xb0
RIP: 0033:0x4e6c1a
Code: Unable to access opcode bytes at RIP 0x4e6bf0.
RSP: 002b:00007ffdb7543730 EFLAGS: 00000206 ORIG_RAX: 0000000000000065
RAX: ffffffffffffffda RBX: 00000000007572f8 RCX: 00000000004e6c1a
RDX: 0000000000000000 RSI: 0000000000000e2e RDI: 0000000000000018
RBP: 0000000000000018 R08: 0000000000000017 R09: 0000000000000002
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000759380
R13: 0000000000000000 R14: 000000000000857f R15: 0000000000617180
</TASK>
INFO: NMI handler (nmi_cpu_backtrace_handler) took too long to run: 1.132 msecs

----------------
Code disassembly (best guess):

0: 86 05 01 00 00 49 xchg %al,0x49000001(%rip) # 0x49000007
6: 83 e9 01 sub $0x1,%ecx
9: 48 89 fd mov %rdi,%rbp
c: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax
13: fc ff df
16: 4d 89 ca mov %r9,%r10
19: 48 c1 ed 03 shr $0x3,%rbp
1d: 49 c1 ea 03 shr $0x3,%r10
21: 48 01 c5 add %rax,%rbp
24: 49 01 c2 add %rax,%r10
27: 48 89 e8 mov %rbp,%rax
* 2a: 49 8d 5a 01 lea 0x1(%r10),%rbx <-- trapping instruction
2e: 48 89 da mov %rbx,%rdx
31: 48 29 ea sub %rbp,%rdx
34: 48 83 fa 10 cmp $0x10,%rdx
38: 7e 63 jle 0x9d
3a: 41 89 eb mov %ebp,%r11d
3d: 41 rex.B
3e: 83 .byte 0x83
3f: e3 .byte 0xe3

[Hillf Danton]

On Sat, 28 May 2022 22:55:22 -0700

To fix task hung, revert ff7f2926114d

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

diff -pur a/net/bluetooth/hci_core.c b/net/bluetooth/hci_core.c
--- a/net/bluetooth/hci_core.c 2022-05-29 17:21:17.147310600 +0800
+++ b/net/bluetooth/hci_core.c 2022-05-29 17:24:16.095788500 +0800
@@ -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))
diff -pur a/net/bluetooth/hci_sync.c b/net/bluetooth/hci_sync.c
--- a/net/bluetooth/hci_sync.c 2022-05-29 17:18:31.625144800 +0800
+++ b/net/bluetooth/hci_sync.c 2022-05-29 17:23:20.415592200 +0800
@@ -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 and the reproducer did not trigger any issue:

Reported-and-tested-by: syzbot+c56f63...@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=d5ef46f0e355ceff
dashboard link: https://syzkaller.appspot.com/bug?extid=c56f6371c48cad0420f9
compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2

patch: https://syzkaller.appspot.com/x/patch.diff?x=15816d23f00000

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

[Tetsuo Handa]

I couldn't agree on that reasoning, and I sent
https://lkml.kernel.org/r/21b9c1ac-64b7-7f4b...@I-love.SAKURA.ne.jp .

[Tetsuo Handa]

#syz fix: Bluetooth: core: Fix deadlock on hci_power_on_sync.

https://lore.kernel.org/netdev/20220623125...@kernel.org/T/