Re: INFO: task hung in usb_bulk_msg

[syzbot]

syzbot has found a reproducer for the following issue on:

HEAD commit:    15bc20c6 Merge tag 'tty-5.9-rc3' of git://git.kernel.org/p..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=1052a669900000
kernel config:  https://syzkaller.appspot.com/x/.config?x=978db74cb30aa994
dashboard link: https://syzkaller.appspot.com/bug?extid=7a7613e5ba9ae7bd15f9
compiler:       gcc (GCC) 10.1.0-syz 20200507
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=101c328e900000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=155eff41900000

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+7a7613e5ba9ae7bd15f9@xxxxxxxxxxxxxxxxxxxxxxxxx

INFO: task syz-executor790:9958 blocked for more than 143 seconds.
      Not tainted 5.9.0-rc2-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor790 state:D stack:28240 pid: 9958 ppid:  6854 flags:0x00004004
Call Trace:
 context_switch kernel/sched/core.c:3778 [inline]
 __schedule+0x8e5/0x21e0 kernel/sched/core.c:4527
 schedule+0xd0/0x2a0 kernel/sched/core.c:4602
 schedule_timeout+0x1d8/0x250 kernel/time/timer.c:1855
 do_wait_for_common kernel/sched/completion.c:85 [inline]
 __wait_for_common kernel/sched/completion.c:106 [inline]
 wait_for_common kernel/sched/completion.c:117 [inline]
 wait_for_completion_timeout+0x15e/0x270 kernel/sched/completion.c:157
 usb_start_wait_urb+0x144/0x2b0 drivers/usb/core/message.c:63
 usb_bulk_msg+0x226/0x550 drivers/usb/core/message.c:254
 do_proc_bulk+0x39b/0x710 drivers/usb/core/devio.c:1231
 proc_bulk drivers/usb/core/devio.c:1268 [inline]
 usbdev_do_ioctl drivers/usb/core/devio.c:2542 [inline]
 usbdev_ioctl+0x586/0x3360 drivers/usb/core/devio.c:2708
 vfs_ioctl fs/ioctl.c:48 [inline]
 __do_sys_ioctl fs/ioctl.c:753 [inline]
 __se_sys_ioctl fs/ioctl.c:739 [inline]
 __x64_sys_ioctl+0x193/0x200 fs/ioctl.c:739
 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x44d089
Code: Bad RIP value.
RSP: 002b:00007f70887dadb8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00000000006dec48 RCX: 000000000044d089
RDX: 0000000020000000 RSI: 00000000c0185502 RDI: 0000000000000003
RBP: 00000000006dec40 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000006dec4c
R13: 00007ffebdfc131f R14: 00007f70887db9c0 R15: 0000000000000064

Showing all locks held in the system:
1 lock held by ksoftirqd/1/16:
 #0: ffff8880ae735e18 (&rq->lock){-.-.}-{2:2}, at: rq_lock kernel/sched/sched.h:1292 [inline]
 #0: ffff8880ae735e18 (&rq->lock){-.-.}-{2:2}, at: __schedule+0x232/0x21e0 kernel/sched/core.c:4445
1 lock held by khungtaskd/1169:
 #0: ffffffff89bd6900 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:5825
1 lock held by in:imklog/6531:
 #0: ffff8880a83bab70 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe9/0x100 fs/file.c:930
3 locks held by kworker/u4:0/6882:
1 lock held by syz-executor790/24330:
 #0: ffff8880ae635e18 (&rq->lock){-.-.}-{2:2}, at: rq_lock kernel/sched/sched.h:1292 [inline]
 #0: ffff8880ae635e18 (&rq->lock){-.-.}-{2:2}, at: __schedule+0x232/0x21e0 kernel/sched/core.c:4445

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

NMI backtrace for cpu 0
CPU: 0 PID: 1169 Comm: khungtaskd Not tainted 5.9.0-rc2-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x18f/0x20d lib/dump_stack.c:118
 nmi_cpu_backtrace.cold+0x70/0xb1 lib/nmi_backtrace.c:101
 nmi_trigger_cpumask_backtrace+0x1b3/0x223 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:209 [inline]
 watchdog+0xd7d/0x1000 kernel/hung_task.c:295
 kthread+0x3b5/0x4a0 kernel/kthread.c:292
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 6851 Comm: syz-executor790 Not tainted 5.9.0-rc2-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:get_timespec64+0x1b3/0x220 kernel/time/time.c:801
Code: 89 73 08 e8 8f f6 10 00 48 b8 00 00 00 00 00 fc ff df 49 c7 04 04 00 00 00 00 48 8b 44 24 58 65 48 2b 04 25 28 00 00 00 75 45 <48> 83 c4 60 44 89 e8 5b 5d 41 5c 41 5d 41 5e c3 e8 58 f6 10 00 45
RSP: 0018:ffffc90001667e20 EFLAGS: 00000246
RAX: 0000000000000000 RBX: ffffc90001667ed0 RCX: ffffffff81634853
RDX: ffff8880a77381c0 RSI: ffffffff81634881 RDI: ffffc90001667ed8
RBP: 0000000000000000 R08: 00000000000f4240 R09: ffffc90001667e4f
R10: 0000000000000000 R11: 0000000000000000 R12: 1ffff920002ccfc4
R13: 0000000000000000 R14: 00000000000f4240 R15: 0000000000000000
FS:  000000000153e880(0000) GS:ffff8880ae700000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00000000004c6238 CR3: 00000000a93cd000 CR4: 00000000001506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 __do_sys_nanosleep kernel/time/hrtimer.c:1962 [inline]
 __se_sys_nanosleep kernel/time/hrtimer.c:1957 [inline]
 __x64_sys_nanosleep+0xaa/0x260 kernel/time/hrtimer.c:1957
 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x44b800
Code: c0 5b 5d c3 66 0f 1f 44 00 00 8b 04 24 48 83 c4 18 5b 5d c3 66 0f 1f 44 00 00 83 3d b1 a0 29 00 00 75 14 b8 23 00 00 00 0f 05 <48> 3d 01 f0 ff ff 0f 83 24 e4 fb ff c3 48 83 ec 08 e8 7a 43 00 00
RSP: 002b:00007ffebdfc1378 EFLAGS: 00000246 ORIG_RAX: 0000000000000023
RAX: ffffffffffffffda RBX: 00000000000025c4 RCX: 000000000044b800
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00007ffebdfc1380
RBP: 000000000009bbed R08: 0000000000000001 R09: 000000000153e880
R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffebdfc13e0
R13: 000000000040a140 R14: 0000000000000000 R15: 0000000000000000