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Date:   Fri, 5 May 2023 11:38:49 -0400
From:   Alan Stern <stern@rowland.harvard.edu>
To:     syzbot <syzbot+e8db9d9e65feff8fa471@syzkaller.appspotmail.com>
Cc:     gregkh@linuxfoundation.org, linux-kernel@vger.kernel.org,
        linux-usb@vger.kernel.org, mailhol.vincent@wanadoo.fr,
        mkl@pengutronix.de, syzkaller-bugs@googlegroups.com,
        Valentina Manea <valentina.manea.m@gmail.com>,
        Shuah Khan <shuah@kernel.org>
Subject: Re: [syzbot] [usb?] INFO: task hung in usb_get_descriptor (2)
Message-ID: <aaf08c6d-b085-4755-afc1-98301106e947@rowland.harvard.edu>
References: <000000000000fd3ea305f0644a0b@google.com>
 <000000000000c2922605faf2baeb@google.com>
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This appears to be related to the usbip driver.  At least, the console 
log is full of references to vhci_hcd.0.

Alan Stern

On Fri, May 05, 2023 at 07:01:45AM -0700, syzbot wrote:
> syzbot has found a reproducer for the following issue on:
> 
> HEAD commit:    3c4aa4434377 Merge tag 'ceph-for-6.4-rc1' of https://githu..
> git tree:       upstream
> console+strace: https://syzkaller.appspot.com/x/log.txt?x=12b780bc280000
> kernel config:  https://syzkaller.appspot.com/x/.config?x=87f9126139666d37
> dashboard link: https://syzkaller.appspot.com/bug?extid=e8db9d9e65feff8fa471
> 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=1132f45c280000
> C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=14328870280000
> 
> Downloadable assets:
> disk image: https://storage.googleapis.com/syzbot-assets/5c99ec63ebd1/disk-3c4aa443.raw.xz
> vmlinux: https://storage.googleapis.com/syzbot-assets/e6de84bd47ce/vmlinux-3c4aa443.xz
> kernel image: https://storage.googleapis.com/syzbot-assets/f12b28027b9e/bzImage-3c4aa443.xz
> 
> IMPORTANT: if you fix the issue, please add the following tag to the commit:
> Reported-by: syzbot+e8db9d9e65feff8fa471@syzkaller.appspotmail.com
> 
> INFO: task kworker/0:2:758 blocked for more than 143 seconds.
>       Not tainted 6.3.0-syzkaller-13091-g3c4aa4434377 #0
> "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
> task:kworker/0:2     state:D stack:25768 pid:758   ppid:2      flags:0x00004000
> Workqueue: usb_hub_wq hub_event
> Call Trace:
>  <TASK>
>  context_switch kernel/sched/core.c:5343 [inline]
>  __schedule+0xc9a/0x5880 kernel/sched/core.c:6669
>  schedule+0xde/0x1a0 kernel/sched/core.c:6745
>  usb_kill_urb.part.0+0x19a/0x220 drivers/usb/core/urb.c:728
>  usb_kill_urb+0x83/0xa0 drivers/usb/core/urb.c:717
>  usb_start_wait_urb+0x24a/0x4b0 drivers/usb/core/message.c:64
>  usb_internal_control_msg drivers/usb/core/message.c:102 [inline]
>  usb_control_msg+0x320/0x4a0 drivers/usb/core/message.c:153
>  usb_get_descriptor+0xe1/0x1d0 drivers/usb/core/message.c:793
>  usb_get_device_descriptor+0x85/0xf0 drivers/usb/core/message.c:1072
>  hub_port_init+0x859/0x3900 drivers/usb/core/hub.c:4969
>  hub_port_connect drivers/usb/core/hub.c:5336 [inline]
>  hub_port_connect_change drivers/usb/core/hub.c:5551 [inline]
>  port_event drivers/usb/core/hub.c:5711 [inline]
>  hub_event+0x2b89/0x4e40 drivers/usb/core/hub.c:5793
>  process_one_work+0x99a/0x15e0 kernel/workqueue.c:2405
>  worker_thread+0x67d/0x10c0 kernel/workqueue.c:2552
>  kthread+0x344/0x440 kernel/kthread.c:379
>  ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308
>  </TASK>
> 
> Showing all locks held in the system:
> 1 lock held by rcu_tasks_kthre/13:
>  #0: ffffffff8c798670 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x31/0xd80 kernel/rcu/tasks.h:518
> 1 lock held by rcu_tasks_trace/14:
>  #0: ffffffff8c798370 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x31/0xd80 kernel/rcu/tasks.h:518
> 1 lock held by khungtaskd/28:
>  #0: ffffffff8c799280 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x340 kernel/locking/lockdep.c:6545
> 5 locks held by kworker/0:2/758:
>  #0: ffff888147e7c138 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline]
>  #0: ffff888147e7c138 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: arch_atomic_long_set include/linux/atomic/atomic-long.h:41 [inline]
>  #0: ffff888147e7c138 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: atomic_long_set include/linux/atomic/atomic-instrumented.h:1324 [inline]
>  #0: ffff888147e7c138 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:643 [inline]
>  #0: ffff888147e7c138 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:670 [inline]
>  #0: ffff888147e7c138 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x883/0x15e0 kernel/workqueue.c:2376
>  #1: ffffc9000404fdb0 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x8b7/0x15e0 kernel/workqueue.c:2380
>  #2: ffff888142b9b190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:837 [inline]
>  #2: ffff888142b9b190 (&dev->mutex){....}-{3:3}, at: hub_event+0x1c0/0x4e40 drivers/usb/core/hub.c:5739
>  #3: ffff888142b9e4f8 (&port_dev->status_lock){+.+.}-{3:3}, at: usb_lock_port drivers/usb/core/hub.c:3147 [inline]
>  #3: ffff888142b9e4f8 (&port_dev->status_lock){+.+.}-{3:3}, at: hub_port_connect drivers/usb/core/hub.c:5303 [inline]
>  #3: ffff888142b9e4f8 (&port_dev->status_lock){+.+.}-{3:3}, at: hub_port_connect_change drivers/usb/core/hub.c:5551 [inline]
>  #3: ffff888142b9e4f8 (&port_dev->status_lock){+.+.}-{3:3}, at: port_event drivers/usb/core/hub.c:5711 [inline]
>  #3: ffff888142b9e4f8 (&port_dev->status_lock){+.+.}-{3:3}, at: hub_event+0x278e/0x4e40 drivers/usb/core/hub.c:5793
>  #4: ffff8881427f4d68 (hcd->address0_mutex){+.+.}-{3:3}, at: hub_port_connect drivers/usb/core/hub.c:5304 [inline]
>  #4: ffff8881427f4d68 (hcd->address0_mutex){+.+.}-{3:3}, at: hub_port_connect_change drivers/usb/core/hub.c:5551 [inline]
>  #4: ffff8881427f4d68 (hcd->address0_mutex){+.+.}-{3:3}, at: port_event drivers/usb/core/hub.c:5711 [inline]
>  #4: ffff8881427f4d68 (hcd->address0_mutex){+.+.}-{3:3}, at: hub_event+0x27c3/0x4e40 drivers/usb/core/hub.c:5793
> 2 locks held by getty/4760:
>  #0: ffff88814ae7f098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x26/0x80 drivers/tty/tty_ldisc.c:243
>  #1: ffffc900015802f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0xef4/0x13e0 drivers/tty/n_tty.c:2176
> 1 lock held by strace-static-x/5000:
>  #0: ffffffff8c40a098 (tasklist_lock){.+.+}-{2:2}, at: raw_spin_rq_lock_nested+0x2f/0x120 kernel/sched/core.c:558
> 2 locks held by dhcpcd/28900:
>  #0: ffff88807a84e130 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1697 [inline]
>  #0: ffff88807a84e130 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: packet_do_bind+0x2f/0xe30 net/packet/af_packet.c:3204
>  #1: ffffffff8c7a46f8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:293 [inline]
>  #1: ffffffff8c7a46f8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x64a/0x770 kernel/rcu/tree_exp.h:992
> 
> =============================================
> 
> NMI backtrace for cpu 0
> CPU: 0 PID: 28 Comm: khungtaskd Not tainted 6.3.0-syzkaller-13091-g3c4aa4434377 #0
> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/14/2023
> Call Trace:
>  <TASK>
>  __dump_stack lib/dump_stack.c:88 [inline]
>  dump_stack_lvl+0xd9/0x150 lib/dump_stack.c:106
>  nmi_cpu_backtrace+0x29c/0x350 lib/nmi_backtrace.c:113
>  nmi_trigger_cpumask_backtrace+0x2a4/0x300 lib/nmi_backtrace.c:62
>  trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline]
>  check_hung_uninterruptible_tasks kernel/hung_task.c:222 [inline]
>  watchdog+0xe16/0x1090 kernel/hung_task.c:379
>  kthread+0x344/0x440 kernel/kthread.c:379
>  ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308
>  </TASK>
> Sending NMI from CPU 0 to CPUs 1:
> NMI backtrace for cpu 1
> CPU: 1 PID: 12 Comm: kworker/u4:1 Not tainted 6.3.0-syzkaller-13091-g3c4aa4434377 #0
> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/14/2023
> Workqueue: events_unbound toggle_allocation_gate
> RIP: 0010:hlock_class kernel/locking/lockdep.c:228 [inline]
> RIP: 0010:__lock_acquire+0x1727/0x5df0 kernel/locking/lockdep.c:5070
> Code: f8 66 81 e3 ff 1f 0f b7 db be 08 00 00 00 48 89 d8 48 c1 e8 06 48 8d 3c c5 00 8d 52 91 e8 51 8b 71 00 48 0f a3 1d f9 e4 ec 0f <0f> 83 51 06 00 00 48 8d 1c 5b 48 c1 e3 06 48 81 c3 20 91 52 91 48
> RSP: 0018:ffffc90000117598 EFLAGS: 00000047
> RAX: 0000000000000001 RBX: 00000000000000bb RCX: ffffffff8165a7ff
> RDX: fffffbfff22a51a3 RSI: 0000000000000008 RDI: ffffffff91528d10
> RBP: 0000000000000000 R08: 0000000000000000 R09: ffffffff91528d17
> R10: fffffbfff22a51a2 R11: 0000000000000000 R12: ffff888016646458
> R13: ffff888016645940 R14: 0000000000000000 R15: c19cd5fde613a6fd
> FS:  0000000000000000(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000
> CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> CR2: 00007fe22eb1e0cf CR3: 000000000c571000 CR4: 00000000003506e0
> DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
> DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
> Call Trace:
>  <TASK>
>  lock_acquire kernel/locking/lockdep.c:5691 [inline]
>  lock_acquire+0x1b1/0x520 kernel/locking/lockdep.c:5656
>  _raw_spin_lock_nested+0x34/0x40 kernel/locking/spinlock.c:378
>  raw_spin_rq_lock_nested+0x2f/0x120 kernel/sched/core.c:558
>  raw_spin_rq_lock kernel/sched/sched.h:1366 [inline]
>  _raw_spin_rq_lock_irqsave kernel/sched/sched.h:1385 [inline]
>  rq_lock_irqsave kernel/sched/sched.h:1637 [inline]
>  update_blocked_averages+0x80/0x1dd0 kernel/sched/fair.c:9021
>  newidle_balance+0x485/0x11d0 kernel/sched/fair.c:11800
>  pick_next_task_fair+0x9a/0x1290 kernel/sched/fair.c:8107
>  __pick_next_task kernel/sched/core.c:5972 [inline]
>  pick_next_task kernel/sched/core.c:6047 [inline]
>  __schedule+0x462/0x5880 kernel/sched/core.c:6633
>  schedule+0xde/0x1a0 kernel/sched/core.c:6745
>  toggle_allocation_gate mm/kfence/core.c:833 [inline]
>  toggle_allocation_gate+0x1ad/0x230 mm/kfence/core.c:823
>  process_one_work+0x99a/0x15e0 kernel/workqueue.c:2405
>  worker_thread+0x67d/0x10c0 kernel/workqueue.c:2552
>  kthread+0x344/0x440 kernel/kthread.c:379
>  ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308
>  </TASK>
> 
> 
> ---
> 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.