KMSAN: uninit-value in rt2500usb_probe_hw

KMSAN: uninit-value in rt2500usb_probe_hw

[syzbot]

Hello,

syzbot found the following crash on:

HEAD commit:    cebbfdbc kmsan: merge set_no_shadow_page() and set_no_orig..
git tree:       https://github.com/google/kmsan.git master
console output: https://syzkaller.appspot.com/x/log.txt?x=1125cb59600000
kernel config:  https://syzkaller.appspot.com/x/.config?x=f03c659d0830ab8d
dashboard link: https://syzkaller.appspot.com/bug?extid=35c80b2190255a410f66
compiler:       clang version 9.0.0 (/home/glider/llvm/clang  
80fee25776c2fb61e74c1ecb1a523375c2500b69)
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=146abd21600000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=106a19b5600000

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+35c80b2190255a410f66@syzkaller.appspotmail.com

usb 1-1: config 0 descriptor??
usb 1-1: reset high-speed USB device number 2 using dummy_hcd
usb 1-1: device descriptor read/64, error -71
usb 1-1: Using ep0 maxpacket: 16
ieee80211 phy3: rt2x00usb_vendor_request: Error - Vendor Request 0x09  
failed for offset 0x0000 with error -71
ieee80211 phy3: rt2x00_set_chip: Info - Chipset detected - rt: 2570, rf:  
0000, rev: 8771
==================================================================
BUG: KMSAN: uninit-value in rt2500usb_init_eeprom  
drivers/net/wireless/ralink/rt2x00/rt2500usb.c:1443 [inline]
BUG: KMSAN: uninit-value in rt2500usb_probe_hw+0xb5e/0x22a0  
drivers/net/wireless/ralink/rt2x00/rt2500usb.c:1757
CPU: 0 PID: 3369 Comm: kworker/0:2 Not tainted 5.3.0-rc7+ #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS  
Google 01/01/2011
Workqueue: usb_hub_wq hub_event
Call Trace:
  __dump_stack lib/dump_stack.c:77 [inline]
  dump_stack+0x191/0x1f0 lib/dump_stack.c:113
  kmsan_report+0x162/0x2d0 mm/kmsan/kmsan_report.c:109
  __msan_warning+0x75/0xe0 mm/kmsan/kmsan_instr.c:294
  rt2500usb_init_eeprom drivers/net/wireless/ralink/rt2x00/rt2500usb.c:1443  
[inline]
  rt2500usb_probe_hw+0xb5e/0x22a0  
drivers/net/wireless/ralink/rt2x00/rt2500usb.c:1757
  rt2x00lib_probe_dev+0xba9/0x3260  
drivers/net/wireless/ralink/rt2x00/rt2x00dev.c:1427
  rt2x00usb_probe+0x7ae/0xf60  
drivers/net/wireless/ralink/rt2x00/rt2x00usb.c:842
  rt2500usb_probe+0x50/0x60  
drivers/net/wireless/ralink/rt2x00/rt2500usb.c:1966
  usb_probe_interface+0xd19/0x1310 drivers/usb/core/driver.c:361
  really_probe+0x1373/0x1dc0 drivers/base/dd.c:552
  driver_probe_device+0x1ba/0x510 drivers/base/dd.c:709
  __device_attach_driver+0x5b8/0x790 drivers/base/dd.c:816
  bus_for_each_drv+0x28e/0x3b0 drivers/base/bus.c:454
  __device_attach+0x489/0x750 drivers/base/dd.c:882
  device_initial_probe+0x4a/0x60 drivers/base/dd.c:929
  bus_probe_device+0x131/0x390 drivers/base/bus.c:514
  device_add+0x25b5/0x2df0 drivers/base/core.c:2165
  usb_set_configuration+0x309f/0x3710 drivers/usb/core/message.c:2027
  generic_probe+0xe7/0x280 drivers/usb/core/generic.c:210
  usb_probe_device+0x146/0x200 drivers/usb/core/driver.c:266
  really_probe+0x1373/0x1dc0 drivers/base/dd.c:552
  driver_probe_device+0x1ba/0x510 drivers/base/dd.c:709
  __device_attach_driver+0x5b8/0x790 drivers/base/dd.c:816
  bus_for_each_drv+0x28e/0x3b0 drivers/base/bus.c:454
  __device_attach+0x489/0x750 drivers/base/dd.c:882
  device_initial_probe+0x4a/0x60 drivers/base/dd.c:929
  bus_probe_device+0x131/0x390 drivers/base/bus.c:514
  device_add+0x25b5/0x2df0 drivers/base/core.c:2165
  usb_new_device+0x23e5/0x2fb0 drivers/usb/core/hub.c:2536
  hub_port_connect drivers/usb/core/hub.c:5098 [inline]
  hub_port_connect_change drivers/usb/core/hub.c:5213 [inline]
  port_event drivers/usb/core/hub.c:5359 [inline]
  hub_event+0x581d/0x72f0 drivers/usb/core/hub.c:5441
  process_one_work+0x1572/0x1ef0 kernel/workqueue.c:2269
  worker_thread+0x111b/0x2460 kernel/workqueue.c:2415
  kthread+0x4b5/0x4f0 kernel/kthread.c:256
  ret_from_fork+0x35/0x40 arch/x86/entry/entry_64.S:355

Local variable description: ----reg.i.i@rt2500usb_probe_hw
Variable was created at:
  rt2500usb_register_read drivers/net/wireless/ralink/rt2x00/rt2500usb.c:51  
[inline]
  rt2500usb_init_eeprom drivers/net/wireless/ralink/rt2x00/rt2500usb.c:1440  
[inline]
  rt2500usb_probe_hw+0x774/0x22a0  
drivers/net/wireless/ralink/rt2x00/rt2500usb.c:1757
  rt2x00lib_probe_dev+0xba9/0x3260  
drivers/net/wireless/ralink/rt2x00/rt2x00dev.c:1427
==================================================================


---
This bug is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
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syzbot can test patches for this bug, for details see:
https://goo.gl/tpsmEJ#testing-patches

Re: KMSAN: uninit-value in rt2500usb_probe_hw

[Dmitry Vyukov]

On Sat, Sep 26, 2020 at 5:25 AM syzbot
<syzbot+35c80b2190255a410f66@syzkaller.appspotmail.com> wrote:
>
> Hello,
>
> syzbot has tested the proposed patch and the reproducer did not trigger any issue:
>
> Reported-and-tested-by: syzbot+35c80b2190255a410f66@syzkaller.appspotmail.com
>
> Tested on:
>
> commit:         c5a13b33 kmsan: clang-format core
> git tree:       https://github.com/google/kmsan.git master
> kernel config:  https://syzkaller.appspot.com/x/.config?x=41fca8ac7f9e770a
> dashboard link: https://syzkaller.appspot.com/bug?extid=35c80b2190255a410f66
> compiler:       clang version 10.0.0 (https://github.com/llvm/llvm-project/ c2443155a0fb245c8f17f2c1c72b6ea391e86e81)
>
> Note: testing is done by a robot and is best-effort only.

Hi Anant,

I see you are testing lots of USB bugs. USB subsystem is currently
broken, testing of any USB bugs will give false "no crash" results,
see:
https://lore.kernel.org/linux-kernel-mentees/CACT4Y+YmbmrH9gCCnCzP-FYa-dKxx9qhKZ+RQxi1f-+Hoj1SUg@mail.gmail.com/

Re: [Linux-kernel-mentees] KMSAN: uninit-value in rt2500usb_probe_hw

[Greg KH]

On Sat, Sep 26, 2020 at 08:53:07AM +0200, Dmitry Vyukov via Linux-kernel-mentees wrote:
> On Sat, Sep 26, 2020 at 5:25 AM syzbot
> <syzbot+35c80b2190255a410f66@syzkaller.appspotmail.com> wrote:
> >
> > Hello,
> >
> > syzbot has tested the proposed patch and the reproducer did not trigger any issue:
> >
> > Reported-and-tested-by: syzbot+35c80b2190255a410f66@syzkaller.appspotmail.com
> >
> > Tested on:
> >
> > commit:         c5a13b33 kmsan: clang-format core
> > git tree:       https://github.com/google/kmsan.git master
> > kernel config:  https://syzkaller.appspot.com/x/.config?x=41fca8ac7f9e770a
> > dashboard link: https://syzkaller.appspot.com/bug?extid=35c80b2190255a410f66
> > compiler:       clang version 10.0.0 (https://github.com/llvm/llvm-project/ c2443155a0fb245c8f17f2c1c72b6ea391e86e81)
> >
> > Note: testing is done by a robot and is best-effort only.
> 
> Hi Anant,
> 
> I see you are testing lots of USB bugs. USB subsystem is currently
> broken, testing of any USB bugs will give false "no crash" results,
> see:
> https://lore.kernel.org/linux-kernel-mentees/CACT4Y+YmbmrH9gCCnCzP-FYa-dKxx9qhKZ+RQxi1f-+Hoj1SUg@mail.gmail.com/

Fixes for this USB problem are in my tree now and should show up in
linux-next on Monday.

thanks,

greg k-h

Re: KMSAN: uninit-value in rt2500usb_probe_hw

[Anant Thazhemadam]

On 26/09/20 12:23 pm, Dmitry Vyukov wrote:
> On Sat, Sep 26, 2020 at 5:25 AM syzbot
> <syzbot+35c80b2190255a410f66@syzkaller.appspotmail.com> wrote:
>> Hello,
>>
>> syzbot has tested the proposed patch and the reproducer did not trigger any issue:
>>
>> Reported-and-tested-by: syzbot+35c80b2190255a410f66@syzkaller.appspotmail.com
>>
>> Tested on:
>>
>> commit:         c5a13b33 kmsan: clang-format core
>> git tree:       https://github.com/google/kmsan.git master
>> kernel config:  https://syzkaller.appspot.com/x/.config?x=41fca8ac7f9e770a
>> dashboard link: https://syzkaller.appspot.com/bug?extid=35c80b2190255a410f66
>> compiler:       clang version 10.0.0 (https://github.com/llvm/llvm-project/ c2443155a0fb245c8f17f2c1c72b6ea391e86e81)
>>
>> Note: testing is done by a robot and is best-effort only.
> Hi Anant,
>
> I see you are testing lots of USB bugs. USB subsystem is currently
> broken, testing of any USB bugs will give false "no crash" results,
> see:
> https://lore.kernel.org/linux-kernel-mentees/CACT4Y+YmbmrH9gCCnCzP-FYa-dKxx9qhKZ+RQxi1f-+Hoj1SUg@mail.gmail.com/

Oh, I see. Thank you for letting me know. I'll be sure to keep that in mind, until I hear
otherwise. :)

Thanks,
Anant

Re: [Linux-kernel-mentees] KMSAN: uninit-value in rt2500usb_probe_hw

[Anant Thazhemadam]

On 26/09/20 12:27 pm, Greg KH wrote:
> On Sat, Sep 26, 2020 at 08:53:07AM +0200, Dmitry Vyukov via Linux-kernel-mentees wrote:
>> On Sat, Sep 26, 2020 at 5:25 AM syzbot
>> <syzbot+35c80b2190255a410f66@syzkaller.appspotmail.com> wrote:
>>> Hello,
>>>
>>> syzbot has tested the proposed patch and the reproducer did not trigger any issue:
>>>
>>> Reported-and-tested-by: syzbot+35c80b2190255a410f66@syzkaller.appspotmail.com
>>>
>>> Tested on:
>>>
>>> commit:         c5a13b33 kmsan: clang-format core
>>> git tree:       https://github.com/google/kmsan.git master
>>> kernel config:  https://syzkaller.appspot.com/x/.config?x=41fca8ac7f9e770a
>>> dashboard link: https://syzkaller.appspot.com/bug?extid=35c80b2190255a410f66
>>> compiler:       clang version 10.0.0 (https://github.com/llvm/llvm-project/ c2443155a0fb245c8f17f2c1c72b6ea391e86e81)
>>>
>>> Note: testing is done by a robot and is best-effort only.
>> Hi Anant,
>>
>> I see you are testing lots of USB bugs. USB subsystem is currently
>> broken, testing of any USB bugs will give false "no crash" results,
>> see:
>> https://lore.kernel.org/linux-kernel-mentees/CACT4Y+YmbmrH9gCCnCzP-FYa-dKxx9qhKZ+RQxi1f-+Hoj1SUg@mail.gmail.com/
> Fixes for this USB problem are in my tree now and should show up in
> linux-next on Monday.
>
> thanks,
>
> greg k-h

Is there any chance you could identify the commit that fixes this bug?
It would help us close the bug for good. :)

Thanks,
Anant

Re: [Linux-kernel-mentees] KMSAN: uninit-value in rt2500usb_probe_hw

[Dmitry Vyukov]

On Wed, Sep 30, 2020 at 5:57 PM Anant Thazhemadam
<anant.thazhemadam@gmail.com> wrote:
> On 26/09/20 12:27 pm, Greg KH wrote:
> > On Sat, Sep 26, 2020 at 08:53:07AM +0200, Dmitry Vyukov via Linux-kernel-mentees wrote:
> >> On Sat, Sep 26, 2020 at 5:25 AM syzbot
> >> <syzbot+35c80b2190255a410f66@syzkaller.appspotmail.com> wrote:
> >>> Hello,
> >>>
> >>> syzbot has tested the proposed patch and the reproducer did not trigger any issue:
> >>>
> >>> Reported-and-tested-by: syzbot+35c80b2190255a410f66@syzkaller.appspotmail.com
> >>>
> >>> Tested on:
> >>>
> >>> commit:         c5a13b33 kmsan: clang-format core
> >>> git tree:       https://github.com/google/kmsan.git master
> >>> kernel config:  https://syzkaller.appspot.com/x/.config?x=41fca8ac7f9e770a
> >>> dashboard link: https://syzkaller.appspot.com/bug?extid=35c80b2190255a410f66
> >>> compiler:       clang version 10.0.0 (https://github.com/llvm/llvm-project/ c2443155a0fb245c8f17f2c1c72b6ea391e86e81)
> >>>
> >>> Note: testing is done by a robot and is best-effort only.
> >> Hi Anant,
> >>
> >> I see you are testing lots of USB bugs. USB subsystem is currently
> >> broken, testing of any USB bugs will give false "no crash" results,
> >> see:
> >> https://lore.kernel.org/linux-kernel-mentees/CACT4Y+YmbmrH9gCCnCzP-FYa-dKxx9qhKZ+RQxi1f-+Hoj1SUg@mail.gmail.com/
> > Fixes for this USB problem are in my tree now and should show up in
> > linux-next on Monday.
> >
> > thanks,
> >
> > greg k-h
>
> Is there any chance you could identify the commit that fixes this bug?
> It would help us close the bug for good. :)

I think Greg meant the fix for the general USB brokenness, not a fix
for this syzbot bug. This bug is not fixed to the best of syzbot
knowledge.

Re: [Linux-kernel-mentees] KMSAN: uninit-value in rt2500usb_probe_hw

[Anant Thazhemadam]

On 30/09/20 9:46 pm, Dmitry Vyukov wrote:
> On Wed, Sep 30, 2020 at 5:57 PM Anant Thazhemadam
> <anant.thazhemadam@gmail.com> wrote:
>> On 26/09/20 12:27 pm, Greg KH wrote:
>>> On Sat, Sep 26, 2020 at 08:53:07AM +0200, Dmitry Vyukov via Linux-kernel-mentees wrote:
>>>> On Sat, Sep 26, 2020 at 5:25 AM syzbot
>>>> <syzbot+35c80b2190255a410f66@syzkaller.appspotmail.com> wrote:
>>>>> Hello,
>>>>>
>>>>> syzbot has tested the proposed patch and the reproducer did not trigger any issue:
>>>>>
>>>>> Reported-and-tested-by: syzbot+35c80b2190255a410f66@syzkaller.appspotmail.com
>>>>>
>>>>> Tested on:
>>>>>
>>>>> commit:         c5a13b33 kmsan: clang-format core
>>>>> git tree:       https://github.com/google/kmsan.git master
>>>>> kernel config:  https://syzkaller.appspot.com/x/.config?x=41fca8ac7f9e770a
>>>>> dashboard link: https://syzkaller.appspot.com/bug?extid=35c80b2190255a410f66
>>>>> compiler:       clang version 10.0.0 (https://github.com/llvm/llvm-project/ c2443155a0fb245c8f17f2c1c72b6ea391e86e81)
>>>>>
>>>>> Note: testing is done by a robot and is best-effort only.
>>>> Hi Anant,
>>>>
>>>> I see you are testing lots of USB bugs. USB subsystem is currently
>>>> broken, testing of any USB bugs will give false "no crash" results,
>>>> see:
>>>> https://lore.kernel.org/linux-kernel-mentees/CACT4Y+YmbmrH9gCCnCzP-FYa-dKxx9qhKZ+RQxi1f-+Hoj1SUg@mail.gmail.com/
>>> Fixes for this USB problem are in my tree now and should show up in
>>> linux-next on Monday.
>>>
>>> thanks,
>>>
>>> greg k-h
>> Is there any chance you could identify the commit that fixes this bug?
>> It would help us close the bug for good. :)
> I think Greg meant the fix for the general USB brokenness, not a fix
> for this syzbot bug. This bug is not fixed to the best of syzbot
> knowledge.

Ah, okay. My bad. I was wondering why the bug wasn't closed already
if there was already a fix. Thank you for clearing that up :)

Thanks,
Anant