WARNING in usb_submit_urb (4)

WARNING in usb_submit_urb (4)

[syzbot]

Hello,

syzbot found the following crash on:

HEAD commit:    163c8d54a997 compiler: remove __no_sanitize_address_or_inl..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=11af34b9400000
kernel config:  https://syzkaller.appspot.com/x/.config?x=8f559fee2fc3375a
dashboard link: https://syzkaller.appspot.com/bug?extid=7634edaea4d0b341c625
compiler:       gcc (GCC) 8.0.1 20180413 (experimental)

Unfortunately, I don't have any reproducer for this crash yet.

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+7634edaea4d0b341c625@syzkaller.appspotmail.com

------------[ cut here ]------------
URB 000000004ff98a65 submitted while active
WARNING: CPU: 1 PID: 17 at drivers/usb/core/urb.c:363  
usb_submit_urb+0x11cf/0x14e0 drivers/usb/core/urb.c:363
Kernel panic - not syncing: panic_on_warn set ...
CPU: 1 PID: 17 Comm: kworker/1:0 Not tainted 4.20.0-rc1+ #322
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS  
Google 01/01/2011
Workqueue: events_power_efficient hub_init_func2
Call Trace:
  __dump_stack lib/dump_stack.c:77 [inline]
  dump_stack+0x244/0x39d lib/dump_stack.c:113
  panic+0x2ad/0x55c kernel/panic.c:188
  __warn.cold.8+0x20/0x45 kernel/panic.c:540
  report_bug+0x254/0x2d0 lib/bug.c:186
  fixup_bug arch/x86/kernel/traps.c:178 [inline]
  do_error_trap+0x11b/0x200 arch/x86/kernel/traps.c:271
  do_invalid_op+0x36/0x40 arch/x86/kernel/traps.c:290
  invalid_op+0x14/0x20 arch/x86/entry/entry_64.S:969
RIP: 0010:usb_submit_urb+0x11cf/0x14e0 drivers/usb/core/urb.c:363
Code: ee e8 c5 f1 7b fc 45 84 ed 0f 85 e2 f6 ff ff e8 e7 f0 7b fc 48 89 de  
48 c7 c7 a0 21 92 88 c6 05 a6 bd 0d 05 01 e8 a1 52 45 fc <0f> 0b e9 c0 f6  
ff ff c7 45 a0 01 00 00 00 e9 65 f7 ff ff 41 bc ed
RSP: 0018:ffff8801d9b5f4f0 EFLAGS: 00010282
RAX: 0000000000000000 RBX: ffff8801cdf30000 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffffffff8165e9b5 RDI: 0000000000000005
RBP: ffff8801d9b5f560 R08: ffff8801d9b4c480 R09: ffffed003b5e5020
R10: ffffed003b5e5020 R11: ffff8801daf28107 R12: 00000000fffffff0
R13: 0000000000000000 R14: 0000000000000009 R15: ffff8801d9b5f6f8
  hub_activate+0xcab/0x1940 drivers/usb/core/hub.c:1215
  hub_init_func2+0x1e/0x30 drivers/usb/core/hub.c:1240
  process_one_work+0xc90/0x1c40 kernel/workqueue.c:2153
  worker_thread+0x17f/0x1390 kernel/workqueue.c:2296
  kthread+0x35a/0x440 kernel/kthread.c:246
  ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352
Kernel Offset: disabled
Rebooting in 86400 seconds..


---
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syzbot.

Re: WARNING in usb_submit_urb (4)

[syzbot]

syzbot has found a reproducer for the following crash on:

HEAD commit:    e12e00e388de Merge tag 'kbuild-fixes-v4.20' of git://git.k..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=100e4ef5400000
kernel config:  https://syzkaller.appspot.com/x/.config?x=8f215f21f041a0d7
dashboard link: https://syzkaller.appspot.com/bug?extid=7634edaea4d0b341c625
compiler:       gcc (GCC) 8.0.1 20180413 (experimental)
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=11ce6fbd400000

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+7634edaea4d0b341c625@syzkaller.appspotmail.com

hub 3-0:1.0: 8 ports detected
hub 3-0:1.0: USB hub found
hub 3-0:1.0: 8 ports detected
------------[ cut here ]------------
URB 000000005e43faa5 submitted while active
WARNING: CPU: 0 PID: 6240 at drivers/usb/core/urb.c:363  
usb_submit_urb+0x11cf/0x14e0 drivers/usb/core/urb.c:363
Kernel panic - not syncing: panic_on_warn set ...
CPU: 0 PID: 6240 Comm: kworker/0:1 Not tainted 4.20.0-rc1+ #332
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS  
Google 01/01/2011
Workqueue: events_power_efficient hub_init_func2
Call Trace:
  __dump_stack lib/dump_stack.c:77 [inline]
  dump_stack+0x244/0x39d lib/dump_stack.c:113
  panic+0x2ad/0x55c kernel/panic.c:188
  __warn.cold.8+0x20/0x45 kernel/panic.c:540
  report_bug+0x254/0x2d0 lib/bug.c:186
  fixup_bug arch/x86/kernel/traps.c:178 [inline]
  do_error_trap+0x11b/0x200 arch/x86/kernel/traps.c:271
  do_invalid_op+0x36/0x40 arch/x86/kernel/traps.c:290
  invalid_op+0x14/0x20 arch/x86/entry/entry_64.S:969
RIP: 0010:usb_submit_urb+0x11cf/0x14e0 drivers/usb/core/urb.c:363
Code: ee e8 95 62 7b fc 45 84 ed 0f 85 e2 f6 ff ff e8 b7 61 7b fc 48 89 de  
48 c7 c7 a0 32 92 88 c6 05 d4 45 0d 05 01 e8 11 c5 44 fc <0f> 0b e9 c0 f6  
ff ff c7 45 a0 01 00 00 00 e9 65 f7 ff ff 41 bc ed
RSP: 0018:ffff8881c1f974f0 EFLAGS: 00010282
RAX: 0000000000000000 RBX: ffff8881c83bb800 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffffffff8165e7e5 RDI: 0000000000000005
RBP: ffff8881c1f97560 R08: ffff8881bc062040 R09: ffffed103b5c3ef8
R10: ffffed103b5c3ef8 R11: ffff8881dae1f7c7 R12: 00000000fffffff0
R13: 0000000000000000 R14: 0000000000000009 R15: ffff8881c1f976f8
  hub_activate+0xcab/0x1940 drivers/usb/core/hub.c:1215
  hub_init_func2+0x1e/0x30 drivers/usb/core/hub.c:1240
  process_one_work+0xc90/0x1c40 kernel/workqueue.c:2153
  worker_thread+0x17f/0x1390 kernel/workqueue.c:2296
  kthread+0x35a/0x440 kernel/kthread.c:246
  ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352
Kernel Offset: disabled
Rebooting in 86400 seconds..

Re: WARNING in usb_submit_urb (4)

[Alan Stern]

On Mon, 12 Nov 2018, syzbot wrote:

> syzbot has found a reproducer for the following crash on:
> 
> HEAD commit:    e12e00e388de Merge tag 'kbuild-fixes-v4.20' of git://git.k..
> git tree:       upstream
> console output: https://syzkaller.appspot.com/x/log.txt?x=100e4ef5400000
> kernel config:  https://syzkaller.appspot.com/x/.config?x=8f215f21f041a0d7
> dashboard link: https://syzkaller.appspot.com/bug?extid=7634edaea4d0b341c625
> compiler:       gcc (GCC) 8.0.1 20180413 (experimental)
> syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=11ce6fbd400000
> 
> IMPORTANT: if you fix the bug, please add the following tag to the commit:
> Reported-by: syzbot+7634edaea4d0b341c625@syzkaller.appspotmail.com

I tried reproducing this bug on my own system, following the 
instructions at

https://github.com/google/syzkaller/blob/master/docs/executing_syzkaller_programs.md

The reproducer failed to run properly.  It produced the following 
output:


$ ./syz-execprog -cover=0 -threaded=1 -repeat=1 -procs=4 /tmp/repro.syz 
2018/11/13 15:29:32 parsed 1 programs
2018/11/13 15:29:32 executed programs: 0
2018/11/13 15:29:32 result: failed=false hanged=false err=executor 3: failed: tun: ioctl(TUNSETIFF) failed (errno 1)
loop failed (errno 0)


tun: ioctl(TUNSETIFF) failed (errno 1)
loop failed (errno 0)


The system is Fedora 28 running the 4.18.16-200.fc28.x86_64 kernel.  
What should I do to investigate further?

Alan Stern

Re: WARNING in usb_submit_urb (4)

[Andrey Konovalov]

On Tue, Nov 13, 2018 at 9:37 PM, Alan Stern <stern@rowland.harvard.edu> wrote:
> On Mon, 12 Nov 2018, syzbot wrote:
>
>> syzbot has found a reproducer for the following crash on:
>>
>> HEAD commit:    e12e00e388de Merge tag 'kbuild-fixes-v4.20' of git://git.k..
>> git tree:       upstream
>> console output: https://syzkaller.appspot.com/x/log.txt?x=100e4ef5400000
>> kernel config:  https://syzkaller.appspot.com/x/.config?x=8f215f21f041a0d7
>> dashboard link: https://syzkaller.appspot.com/bug?extid=7634edaea4d0b341c625
>> compiler:       gcc (GCC) 8.0.1 20180413 (experimental)
>> syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=11ce6fbd400000
>>
>> IMPORTANT: if you fix the bug, please add the following tag to the commit:
>> Reported-by: syzbot+7634edaea4d0b341c625@syzkaller.appspotmail.com
>
> I tried reproducing this bug on my own system, following the
> instructions at
>
> https://github.com/google/syzkaller/blob/master/docs/executing_syzkaller_programs.md
>
> The reproducer failed to run properly.  It produced the following
> output:
>
>
> $ ./syz-execprog -cover=0 -threaded=1 -repeat=1 -procs=4 /tmp/repro.syz
> 2018/11/13 15:29:32 parsed 1 programs
> 2018/11/13 15:29:32 executed programs: 0
> 2018/11/13 15:29:32 result: failed=false hanged=false err=executor 3: failed: tun: ioctl(TUNSETIFF) failed (errno 1)
> loop failed (errno 0)
>
>
> tun: ioctl(TUNSETIFF) failed (errno 1)
> loop failed (errno 0)
>
>
> The system is Fedora 28 running the 4.18.16-200.fc28.x86_64 kernel.
> What should I do to investigate further?

Hi Alan,

Looking at "errno 1", it seems that syz-execprog doesn't have enough
privileges to execute this ioctl, so you might need to run it as root.

However the absence of a C reproducer points to the fact that this is
some kind of a race condition. Those are quite sensitive to timing,
and any difference in the used setup might affect their
reproducibility. I would recommend building the exact kernel revision
with the provided config. For me it took around 3 minutes to
syz-execprog before I saw the WARNING.

Thanks!

Re: WARNING in usb_submit_urb (4)

[syzbot]

syzbot has bisected this bug to:

commit c470abd4fde40ea6a0846a2beab642a578c0b8cd
Author: Linus Torvalds <torvalds@linux-foundation.org>
Date:   Sun Feb 19 22:34:00 2017 +0000

     Linux 4.10

bisection log:  https://syzkaller.appspot.com/x/bisect.txt?x=11b415ed200000
start commit:   e12e00e3 Merge tag 'kbuild-fixes-v4.20' of git://git.kerne..
git tree:       upstream
kernel config:  https://syzkaller.appspot.com/x/.config?x=8f215f21f041a0d7
dashboard link: https://syzkaller.appspot.com/bug?extid=7634edaea4d0b341c625
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=11ce6fbd400000

Reported-by: syzbot+7634edaea4d0b341c625@syzkaller.appspotmail.com
Fixes: c470abd4fde4 ("Linux 4.10")

For information about bisection process see: https://goo.gl/tpsmEJ#bisection