[syzbot] INFO: task hung in do_proc_bulk

From: syzbot
Date: Sat Aug 28 2021 - 11:52:21 EST

Hello,

syzbot found the following issue on:

HEAD commit: d5ae8d7f85b7 Revert "media: dvb header files: move some he..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=155fa21e300000
kernel config: https://syzkaller.appspot.com/x/.config?x=2fd902af77ff1e56
dashboard link: https://syzkaller.appspot.com/bug?extid=ada0f7d3d9fd2016d927
compiler: Debian clang version 11.0.1-2, GNU ld (GNU Binutils for Debian) 2.35.1
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=11a1ab0e300000

Bisection is inconclusive: the issue happens on the oldest tested release.

bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=15662ee1300000
final oops: https://syzkaller.appspot.com/x/report.txt?x=17662ee1300000
console output: https://syzkaller.appspot.com/x/log.txt?x=13662ee1300000

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+ada0f7d3d9fd2016d927@xxxxxxxxxxxxxxxxxxxxxxxxx

INFO: task syz-executor.0:8700 blocked for more than 143 seconds.
Not tainted 5.14.0-rc7-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor.0 state:D stack:23192 pid: 8700 ppid: 8455 flags:0x00004004
Call Trace:
context_switch kernel/sched/core.c:4681 [inline]
__schedule+0xc07/0x11f0 kernel/sched/core.c:5938
schedule+0x14b/0x210 kernel/sched/core.c:6017
schedule_timeout+0x98/0x2f0 kernel/time/timer.c:1857
do_wait_for_common+0x2da/0x480 kernel/sched/completion.c:85
__wait_for_common kernel/sched/completion.c:106 [inline]
wait_for_common kernel/sched/completion.c:117 [inline]
wait_for_completion_timeout+0x46/0x60 kernel/sched/completion.c:157
usb_start_wait_urb+0x167/0x550 drivers/usb/core/message.c:63
do_proc_bulk+0x978/0x1080 drivers/usb/core/devio.c:1236
proc_bulk drivers/usb/core/devio.c:1273 [inline]
usbdev_do_ioctl drivers/usb/core/devio.c:2547 [inline]
usbdev_ioctl+0x3441/0x6b10 drivers/usb/core/devio.c:2713
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:1069 [inline]
__se_sys_ioctl+0xfb/0x170 fs/ioctl.c:1055
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x4665e9
RSP: 002b:00007f15a90dc188 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 000000000056bf80 RCX: 00000000004665e9
RDX: 0000000020000340 RSI: 00000000c0185502 RDI: 0000000000000004
RBP: 00000000004bfcc4 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056bf80
R13: 00007ffcc552e1bf R14: 00007f15a90dc300 R15: 0000000000022000

Showing all locks held in the system:
1 lock held by khungtaskd/1610:
#0: ffffffff8c717ec0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30 arch/x86/pci/mmconfig_64.c:151
1 lock held by in:imklog/8130:
#0: ffff888035998870 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x24e/0x2f0 fs/file.c:974

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

NMI backtrace for cpu 1
CPU: 1 PID: 1610 Comm: khungtaskd Not tainted 5.14.0-rc7-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0x1d3/0x29f lib/dump_stack.c:105
nmi_cpu_backtrace+0x16c/0x190 lib/nmi_backtrace.c:105
nmi_trigger_cpumask_backtrace+0x191/0x2f0 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:210 [inline]
watchdog+0xd06/0xd50 kernel/hung_task.c:295
kthread+0x453/0x480 kernel/kthread.c:319
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 10 Comm: kworker/u4:1 Not tainted 5.14.0-rc7-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: bat_events batadv_nc_worker
RIP: 0010:lock_is_held_type+0x1/0x180 kernel/locking/lockdep.c:5653
Code: 74 df 83 3d d8 22 e1 03 00 75 d6 48 c7 c7 80 c3 2e 8a 48 c7 c6 c0 c3 2e 8a 31 c0 e8 c9 8d 72 f7 0f 0b eb bd e8 90 fd ff ff 55 <41> 57 41 56 41 55 41 54 53 48 83 ec 10 65 48 8b 04 25 28 00 00 00
RSP: 0018:ffffc90000cf7990 EFLAGS: 00000202
RAX: 1ffffffff18e3801 RBX: 1ffff9200019ef34 RCX: 0000000080000001
RDX: 0000000000000000 RSI: 00000000ffffffff RDI: ffffffff8c717e20
RBP: ffffc90000cf7a28 R08: dffffc0000000000 R09: fffffbfff1b74ee6
R10: fffffbfff1b74ee6 R11: 0000000000000000 R12: dffffc0000000000
R13: 1ffff9200019ef58 R14: dffffc0000000000 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f0a1e997000 CR3: 000000000c48e000 CR4: 00000000001506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
lock_is_held include/linux/lockdep.h:283 [inline]
rcu_read_lock_sched_held+0x87/0x110 kernel/rcu/update.c:125
trace_lock_acquire+0x59/0x190 include/trace/events/lock.h:13
lock_acquire+0xa4/0x4a0 kernel/locking/lockdep.c:5596
rcu_lock_acquire+0x2a/0x30 include/linux/rcupdate.h:267
rcu_read_lock include/linux/rcupdate.h:687 [inline]
batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:404 [inline]
batadv_nc_worker+0xc8/0x5b0 net/batman-adv/network-coding.c:715
process_one_work+0x833/0x10c0 kernel/workqueue.c:2276
worker_thread+0xac1/0x1320 kernel/workqueue.c:2422
kthread+0x453/0x480 kernel/kthread.c:319
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
----------------
Code disassembly (best guess):
0: 74 df je 0xffffffe1
2: 83 3d d8 22 e1 03 00 cmpl $0x0,0x3e122d8(%rip) # 0x3e122e1
9: 75 d6 jne 0xffffffe1
b: 48 c7 c7 80 c3 2e 8a mov $0xffffffff8a2ec380,%rdi
12: 48 c7 c6 c0 c3 2e 8a mov $0xffffffff8a2ec3c0,%rsi
19: 31 c0 xor %eax,%eax
1b: e8 c9 8d 72 f7 callq 0xf7728de9
20: 0f 0b ud2
22: eb bd jmp 0xffffffe1
24: e8 90 fd ff ff callq 0xfffffdb9
29: 55 push %rbp
* 2a: 41 57 push %r15 <-- trapping instruction
2c: 41 56 push %r14
2e: 41 55 push %r13
30: 41 54 push %r12
32: 53 push %rbx
33: 48 83 ec 10 sub $0x10,%rsp
37: 65 48 8b 04 25 28 00 mov %gs:0x28,%rax
3e: 00 00


---
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For information about bisection process see: https://goo.gl/tpsmEJ#bisection
syzbot can test patches for this issue, for details see:
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