[syzbot] [kernel?] INFO: task hung in hci_dev_open (2)

[syzbot <syzbot+b3b33ad3a3e6369375a7@syzkaller.appspotmail.com>]

Hello,

syzbot found the following issue on:

HEAD commit:    ae9b3c0e79bc Merge branch 'tcp-allow-to-reduce-max-rto'
git tree:       net-next
console output: https://syzkaller.appspot.com/x/log.txt?x=11e00aa4580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=1909f2f0d8e641ce
dashboard link: https://syzkaller.appspot.com/bug?extid=b3b33ad3a3e6369375a7
compiler:       Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=161e23f8580000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/93d74fa441be/disk-ae9b3c0e.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/e226dd1d1f06/vmlinux-ae9b3c0e.xz
kernel image: https://storage.googleapis.com/syzbot-assets/423579a2a07e/bzImage-ae9b3c0e.xz

The issue was bisected to:

commit 5a781ccbd19e4664babcbe4b4ead7aa2b9283d22
Author: Vinicius Costa Gomes <vinicius.gomes@intel.com>
Date:   Sat Sep 29 00:59:43 2018 +0000

    tc: Add support for configuring the taprio scheduler

bisection log:  https://syzkaller.appspot.com/x/bisect.txt?x=126b4718580000
final oops:     https://syzkaller.appspot.com/x/report.txt?x=116b4718580000
console output: https://syzkaller.appspot.com/x/log.txt?x=166b4718580000

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+b3b33ad3a3e6369375a7@syzkaller.appspotmail.com
Fixes: 5a781ccbd19e ("tc: Add support for configuring the taprio scheduler")

INFO: task syz-executor:6086 blocked for more than 178 seconds.
      Not tainted 6.14.0-rc1-syzkaller-00272-gae9b3c0e79bc #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor    state:D stack:25984 pid:6086  tgid:6086  ppid:6085   task_flags:0x400140 flags:0x00000000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5377 [inline]
 __schedule+0x190e/0x4c90 kernel/sched/core.c:6764
 __schedule_loop kernel/sched/core.c:6841 [inline]
 schedule+0x14b/0x320 kernel/sched/core.c:6856
 schedule_timeout+0xb0/0x290 kernel/time/sleep_timeout.c:75
 do_wait_for_common kernel/sched/completion.c:95 [inline]
 __wait_for_common kernel/sched/completion.c:116 [inline]
 wait_for_common kernel/sched/completion.c:127 [inline]
 wait_for_completion+0x355/0x620 kernel/sched/completion.c:148
 __flush_workqueue+0x575/0x1280 kernel/workqueue.c:3998
 hci_dev_open+0x149/0x300 net/bluetooth/hci_core.c:455
 sock_do_ioctl+0x158/0x460 net/socket.c:1194
 sock_ioctl+0x626/0x8e0 net/socket.c:1313
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:906 [inline]
 __se_sys_ioctl+0xf5/0x170 fs/ioctl.c:892
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f940718c9eb
RSP: 002b:00007fff6ef05ae0 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007f940718c9eb
RDX: 0000000000000005 RSI: 00000000400448c9 RDI: 0000000000000003
RBP: 00007fff6ef05b4c R08: 0000000000000000 R09: 00007fff6ef05a57
R10: 0000000000000008 R11: 0000000000000246 R12: 0000000000000005
R13: 0000000000000005 R14: 0000000000000009 R15: 0000000000000000
 </TASK>

Showing all locks held in the system:
3 locks held by kworker/0:0/8:
3 locks held by kworker/1:0/25:
1 lock held by khungtaskd/30:
 #0: ffffffff8e9387e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline]
 #0: ffffffff8e9387e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #0: ffffffff8e9387e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x55/0x2a0 kernel/locking/lockdep.c:6746
2 locks held by kworker/u8:3/51:
 #0: ffff88801ac89148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3211 [inline]
 #0: ffff88801ac89148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x93b/0x1840 kernel/workqueue.c:3317
 #1: ffffc90000bc7c60 ((work_completion)(&pool->idle_cull_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3212 [inline]
 #1: ffffc90000bc7c60 ((work_completion)(&pool->idle_cull_work)){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1840 kernel/workqueue.c:3317
3 locks held by kworker/u9:0/53:
 #0: ffff88807da56148 ((wq_completion)hci5){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3211 [inline]
 #0: ffff88807da56148 ((wq_completion)hci5){+.+.}-{0:0}, at: process_scheduled_works+0x93b/0x1840 kernel/workqueue.c:3317
 #1: ffffc90000be7c60 ((work_completion)(&hdev->power_on)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3212 [inline]
 #1: ffffc90000be7c60 ((work_completion)(&hdev->power_on)){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1840 kernel/workqueue.c:3317
 #2: ffff88805a3d8d80 (&hdev->req_lock){+.+.}-{4:4}, at: hci_dev_do_open net/bluetooth/hci_core.c:409 [inline]
 #2: ffff88805a3d8d80 (&hdev->req_lock){+.+.}-{4:4}, at: hci_power_on+0x1bf/0x6b0 net/bluetooth/hci_core.c:940
3 locks held by kworker/1:2/974:
 #0: ffff88801ac81d48 ((wq_completion)events_power_efficient){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3211 [inline]
 #0: ffff88801ac81d48 ((wq_completion)events_power_efficient){+.+.}-{0:0}, at: process_scheduled_works+0x93b/0x1840 kernel/workqueue.c:3317
 #1: ffffc90003a0fc60 ((crda_timeout).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3212 [inline]
 #1: ffffc90003a0fc60 ((crda_timeout).work){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1840 kernel/workqueue.c:3317
 #2: ffffffff8fcc0208 (rtnl_mutex){+.+.}-{4:4}, at: crda_timeout_work+0x15/0x50 net/wireless/reg.c:540
5 locks held by kworker/u8:5/1025:
3 locks held by kworker/u8:8/1153:
 #0: ffff888030945148 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3211 [inline]
 #0: ffff888030945148 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0x93b/0x1840 kernel/workqueue.c:3317
 #1: ffffc90003d0fc60 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3212 [inline]
 #1: ffffc90003d0fc60 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1840 kernel/workqueue.c:3317
 #2: ffffffff8fcc0208 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
 #2: ffffffff8fcc0208 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_dad_work+0x10e/0x16a0 net/ipv6/addrconf.c:4190
3 locks held by kworker/0:2/1165:
4 locks held by kworker/u9:1/5146:
 #0: ffff88802976d948 ((wq_completion)hci1){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3211 [inline]
 #0: ffff88802976d948 ((wq_completion)hci1){+.+.}-{0:0}, at: process_scheduled_works+0x93b/0x1840 kernel/workqueue.c:3317
 #1: ffffc900106d7c60 ((work_completion)(&hdev->cmd_sync_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3212 [inline]
 #1: ffffc900106d7c60 ((work_completion)(&hdev->cmd_sync_work)){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1840 kernel/workqueue.c:3317
 #2: ffff888025450d80 (&hdev->req_lock){+.+.}-{4:4}, at: hci_cmd_sync_work+0x1ec/0x400 net/bluetooth/hci_sync.c:331
 #3: ffff888025450078 (&hdev->lock){+.+.}-{4:4}, at: hci_abort_conn_sync+0x1e4/0x11f0 net/bluetooth/hci_sync.c:5569
2 locks held by dhcpcd/5502:
2 locks held by getty/5586:
 #0: ffff8880355800a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
 #1: ffffc90002fde2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x6a6/0x1e00 drivers/tty/n_tty.c:2211
1 lock held by syz-execprog/5826:
4 locks held by kworker/u9:2/5851:
 #0: ffff88802991a148 ((wq_completion)hci3){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3211 [inline]
 #0: ffff88802991a148 ((wq_completion)hci3){+.+.}-{0:0}, at: process_scheduled_works+0x93b/0x1840 kernel/workqueue.c:3317
 #1: ffffc900041bfc60 ((work_completion)(&hdev->cmd_sync_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3212 [inline]
 #1: ffffc900041bfc60 ((work_completion)(&hdev->cmd_sync_work)){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1840 kernel/workqueue.c:3317


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