[syzbot] [kernel?] INFO: task hung in worker_thread (5)

[syzbot <syzbot+c27cd2da6c2dc003b4a1@syzkaller.appspotmail.com>]

Hello,

syzbot found the following issue on:

HEAD commit:    aa486552a110 Merge tag 'memblock-v6.12-rc1' of git://git.k..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=1482da80580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=6c71bad3e6ab6955
dashboard link: https://syzkaller.appspot.com/bug?extid=c27cd2da6c2dc003b4a1
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=12afcaa9980000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=10edb627980000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/7c6beec63de3/disk-aa486552.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/fa35efb3dd39/vmlinux-aa486552.xz
kernel image: https://storage.googleapis.com/syzbot-assets/537d8ff45d85/bzImage-aa486552.xz

The issue was bisected to:

commit d15121be7485655129101f3960ae6add40204463
Author: Paolo Abeni <pabeni@redhat.com>
Date:   Mon May 8 06:17:44 2023 +0000

    Revert "softirq: Let ksoftirqd do its job"

bisection log:  https://syzkaller.appspot.com/x/bisect.txt?x=153d06a9980000
console output: https://syzkaller.appspot.com/x/log.txt?x=133d06a9980000

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+c27cd2da6c2dc003b4a1@syzkaller.appspotmail.com
Fixes: d15121be7485 ("Revert "softirq: Let ksoftirqd do its job"")

INFO: task kworker/1:1:51 blocked for more than 145 seconds.
      Not tainted 6.11.0-syzkaller-10622-gaa486552a110 #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/1:1     state:R  running task     stack:23864 pid:51    tgid:51    ppid:2      flags:0x00004000
Workqueue:  0x0 (events)
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5315 [inline]
 __schedule+0x1895/0x4b30 kernel/sched/core.c:6675
 __schedule_loop kernel/sched/core.c:6752 [inline]
 schedule+0x14b/0x320 kernel/sched/core.c:6767
 worker_thread+0xa30/0xd30 kernel/workqueue.c:3406
 kthread+0x2f0/0x390 kernel/kthread.c:389
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>

Showing all locks held in the system:
3 locks held by kworker/u8:0/11:
1 lock held by khungtaskd/30:
 #0: ffffffff8e937ee0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline]
 #0: ffffffff8e937ee0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #0: ffffffff8e937ee0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x2a0 kernel/locking/lockdep.c:6701
5 locks held by kworker/u8:3/52:
5 locks held by kworker/u9:0/54:
 #0: ffff88801ef05948 ((wq_completion)hci1){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3204 [inline]
 #0: ffff88801ef05948 ((wq_completion)hci1){+.+.}-{0:0}, at: process_scheduled_works+0x93b/0x1850 kernel/workqueue.c:3310
 #1: ffffc90000bf7d00 ((work_completion)(&hdev->cmd_sync_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3205 [inline]
 #1: ffffc90000bf7d00 ((work_completion)(&hdev->cmd_sync_work)){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1850 kernel/workqueue.c:3310
 #2: ffff88807fa38d80 (&hdev->req_lock){+.+.}-{3:3}, at: hci_cmd_sync_work+0x1ec/0x400 net/bluetooth/hci_sync.c:327
 #3: ffff88807fa38078 (&hdev->lock){+.+.}-{3:3}, at: hci_abort_conn_sync+0x1ea/0xde0 net/bluetooth/hci_sync.c:5567
 #4: ffffffff8fe3e0a8 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_connect_cfm include/net/bluetooth/hci_core.h:1957 [inline]
 #4: ffffffff8fe3e0a8 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_conn_failed+0x15d/0x300 net/bluetooth/hci_conn.c:1262


---
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 syzkaller@googlegroups.com.

syzbot will keep track of this issue. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
For information about bisection process see: https://goo.gl/tpsmEJ#bisection

If the report is already addressed, let syzbot know by replying with:
#syz fix: exact-commit-title

If you want syzbot to run the reproducer, reply with:
#syz test: git://repo/address.git branch-or-commit-hash
If you attach or paste a git patch, syzbot will apply it before testing.

If you want to overwrite report's subsystems, reply with:
#syz set subsystems: new-subsystem
(See the list of subsystem names on the web dashboard)

If the report is a duplicate of another one, reply with:
#syz dup: exact-subject-of-another-report

If you want to undo deduplication, reply with:
#syz undup