KMSAN: kernel-usb-infoleak in pcan_usb_pro_send_req

[syzbot]

Hello,

syzbot found the following crash on:

HEAD commit: 41550654 [UPSTREAM] KVM: x86: degrade WARN to pr_warn_rate..
git tree: kmsan
console output: https://syzkaller.appspot.com/x/log.txt?x=13e95183a00000
kernel config: https://syzkaller.appspot.com/x/.config?x=40511ad0c5945201
dashboard link: https://syzkaller.appspot.com/bug?extid=513e4d0985298538bf9b
compiler: clang version 9.0.0 (/home/glider/llvm/clang
80fee25776c2fb61e74c1ecb1a523375c2500b69)
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=17eafa1ba00000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=17b87983a00000

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+513e4d...@syzkaller.appspotmail.com

usb 1-1: config 0 has no interface number 0
usb 1-1: New USB device found, idVendor=0c72, idProduct=0014,
bcdDevice=8b.53
usb 1-1: New USB device strings: Mfr=0, Product=0, SerialNumber=0
usb 1-1: config 0 descriptor??
peak_usb 1-1:0.146: PEAK-System PCAN-USB X6 v0 fw v0.0.0 (2 channels)
==================================================================
BUG: KMSAN: kernel-usb-infoleak in usb_submit_urb+0x7ef/0x1f50
drivers/usb/core/urb.c:405
CPU: 0 PID: 3359 Comm: kworker/0:2 Not tainted 5.2.0-rc4+ #7
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.c:611
kmsan_internal_check_memory+0x974/0xa80 mm/kmsan/kmsan.c:705
kmsan_handle_urb+0x28/0x40 mm/kmsan/kmsan_hooks.c:617
usb_submit_urb+0x7ef/0x1f50 drivers/usb/core/urb.c:405
usb_start_wait_urb+0x143/0x410 drivers/usb/core/message.c:58
usb_internal_control_msg drivers/usb/core/message.c:102 [inline]
usb_control_msg+0x49f/0x7f0 drivers/usb/core/message.c:156
pcan_usb_pro_send_req+0x26b/0x3e0
drivers/net/can/usb/peak_usb/pcan_usb_pro.c:336
pcan_usb_fd_drv_loaded drivers/net/can/usb/peak_usb/pcan_usb_fd.c:460
[inline]
pcan_usb_fd_init+0x16ee/0x1900
drivers/net/can/usb/peak_usb/pcan_usb_fd.c:885
peak_usb_create_dev drivers/net/can/usb/peak_usb/pcan_usb_core.c:809
[inline]
peak_usb_probe+0x1416/0x1b20
drivers/net/can/usb/peak_usb/pcan_usb_core.c:907
usb_probe_interface+0xd19/0x1310 drivers/usb/core/driver.c:361
really_probe+0x1344/0x1d90 drivers/base/dd.c:513
driver_probe_device+0x1ba/0x510 drivers/base/dd.c:670
__device_attach_driver+0x5b8/0x790 drivers/base/dd.c:777
bus_for_each_drv+0x28e/0x3b0 drivers/base/bus.c:454
__device_attach+0x489/0x750 drivers/base/dd.c:843
device_initial_probe+0x4a/0x60 drivers/base/dd.c:890


---
This bug is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzk...@googlegroups.com.

syzbot will keep track of this bug report. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
syzbot can test patches for this bug, for details see:
https://goo.gl/tpsmEJ#testing-patches

[Alan Stern]

On Tue, 30 Jul 2019, syzbot wrote:

> Hello,
>
> syzbot found the following crash on:
>
> HEAD commit: 41550654 [UPSTREAM] KVM: x86: degrade WARN to pr_warn_rate..
> git tree: kmsan
> console output: https://syzkaller.appspot.com/x/log.txt?x=13e95183a00000
> kernel config: https://syzkaller.appspot.com/x/.config?x=40511ad0c5945201
> dashboard link: https://syzkaller.appspot.com/bug?extid=513e4d0985298538bf9b
> compiler: clang version 9.0.0 (/home/glider/llvm/clang
> 80fee25776c2fb61e74c1ecb1a523375c2500b69)
> syz repro: https://syzkaller.appspot.com/x/repro.syz?x=17eafa1ba00000
> C reproducer: https://syzkaller.appspot.com/x/repro.c?x=17b87983a00000
>
> IMPORTANT: if you fix the bug, please add the following tag to the commit:
> Reported-by: syzbot+513e4d...@syzkaller.appspotmail.com
>
> usb 1-1: config 0 has no interface number 0
> usb 1-1: New USB device found, idVendor=0c72, idProduct=0014,
> bcdDevice=8b.53
> usb 1-1: New USB device strings: Mfr=0, Product=0, SerialNumber=0
> usb 1-1: config 0 descriptor??
> peak_usb 1-1:0.146: PEAK-System PCAN-USB X6 v0 fw v0.0.0 (2 channels)
> ==================================================================
> BUG: KMSAN: kernel-usb-infoleak in usb_submit_urb+0x7ef/0x1f50
> drivers/usb/core/urb.c:405

What does "kernel-usb-infoleak" mean?

Alan Stern

[Andrey Konovalov]

That means that the kernel put some uninitialized data into a request
that was sent to a USB device.

>
> Alan Stern
>

[Andrey Konovalov]

Here's a better report for this bug:

https://syzkaller.appspot.com/text?tag=CrashReport&x=11dae8ec600000

This is a real bug, I was able to reproduce it with a hardware
reproducer and leak some kernel pointers AFAIR.

>
> >
> > Alan Stern
> >

[Alexander Potapenko]

Yes, for some reason syzkaller lost half of the original report when
reproducing the bug.

> https://syzkaller.appspot.com/text?tag=CrashReport&x=11dae8ec600000
>
> This is a real bug, I was able to reproduce it with a hardware
> reproducer and leak some kernel pointers AFAIR.

> >
> > >
> > > Alan Stern
> > >
>

> --
> You received this message because you are subscribed to the Google Groups "syzkaller-bugs" group.
> To unsubscribe from this group and stop receiving emails from it, send an email to syzkaller-bug...@googlegroups.com.
> To view this discussion on the web visit https://groups.google.com/d/msgid/syzkaller-bugs/CAAeHK%2Bz50rsvQypF5AivYJh0wQ04XAueC%3DMs2cPt3%2BQuN1%2BKGg%40mail.gmail.com.



--
Alexander Potapenko
Software Engineer

Google Germany GmbH
Erika-Mann-Straße, 33
80636 München

Geschäftsführer: Paul Manicle, Halimah DeLaine Prado
Registergericht und -nummer: Hamburg, HRB 86891
Sitz der Gesellschaft: Hamburg

[Oliver Neukum]

Am Dienstag, den 30.07.2019, 02:38 -0700 schrieb syzbot:
> Hello,
>
> syzbot found the following crash on:
>
> HEAD commit: 41550654 [UPSTREAM] KVM: x86: degrade WARN to pr_warn_rate..
> git tree: kmsan
> console output: https://syzkaller.appspot.com/x/log.txt?x=13e95183a00000
> kernel config: https://syzkaller.appspot.com/x/.config?x=40511ad0c5945201
> dashboard link: https://syzkaller.appspot.com/bug?extid=513e4d0985298538bf9b
> compiler: clang version 9.0.0 (/home/glider/llvm/clang
> 80fee25776c2fb61e74c1ecb1a523375c2500b69)
> syz repro: https://syzkaller.appspot.com/x/repro.syz?x=17eafa1ba00000
> C reproducer: https://syzkaller.appspot.com/x/repro.c?x=17b87983a00000
>
> IMPORTANT: if you fix the bug, please add the following tag to the commit:
> Reported-by: syzbot+513e4d...@syzkaller.appspotmail.com

#syz test: https://github.com/google/kasan.git 41550654

From 6de76fa3df8aedc7a76dc0ecdea8308e38d4dccc Mon Sep 17 00:00:00 2001
From: Oliver Neukum <one...@suse.com>
Date: Tue, 6 Aug 2019 14:41:52 +0200
Subject: [PATCH] pcan_usb_fd: zero out the common command buffer

Lest we leak kernel memory to a device we better zero out buffers.

Signed-off-by: Oliver Neukum <one...@suse.com>
---
drivers/net/can/usb/peak_usb/pcan_usb_fd.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/can/usb/peak_usb/pcan_usb_fd.c b/drivers/net/can/usb/peak_usb/pcan_usb_fd.c
index 34761c3a6286..47cc1ff5b88e 100644
--- a/drivers/net/can/usb/peak_usb/pcan_usb_fd.c
+++ b/drivers/net/can/usb/peak_usb/pcan_usb_fd.c
@@ -841,7 +841,7 @@ static int pcan_usb_fd_init(struct peak_usb_device *dev)
goto err_out;

/* allocate command buffer once for all for the interface */
- pdev->cmd_buffer_addr = kmalloc(PCAN_UFD_CMD_BUFFER_SIZE,
+ pdev->cmd_buffer_addr = kzalloc(PCAN_UFD_CMD_BUFFER_SIZE,
GFP_KERNEL);
if (!pdev->cmd_buffer_addr)
goto err_out_1;
--
2.16.4

[syzbot]

> Am Dienstag, den 30.07.2019, 02:38 -0700 schrieb syzbot:
>> Hello,

>> syzbot found the following crash on:

>> HEAD commit: 41550654 [UPSTREAM] KVM: x86: degrade WARN to
>> pr_warn_rate..
>> git tree: kmsan
>> console output: https://syzkaller.appspot.com/x/log.txt?x=13e95183a00000
>> kernel config:
>> https://syzkaller.appspot.com/x/.config?x=40511ad0c5945201
>> dashboard link:
>> https://syzkaller.appspot.com/bug?extid=513e4d0985298538bf9b
>> compiler: clang version 9.0.0 (/home/glider/llvm/clang
>> 80fee25776c2fb61e74c1ecb1a523375c2500b69)
>> syz repro:
>> https://syzkaller.appspot.com/x/repro.syz?x=17eafa1ba00000
>> C reproducer: https://syzkaller.appspot.com/x/repro.c?x=17b87983a00000

>> IMPORTANT: if you fix the bug, please add the following tag to the
>> commit:
>> Reported-by: syzbot+513e4d...@syzkaller.appspotmail.com

> #syz test: https://github.com/google/kasan.git 41550654

KMSAN bugs can only be tested on https://github.com/google/kmsan.git tree
because KMSAN tool is not upstreamed yet.
See https://goo.gl/tpsmEJ#kmsan-bugs for details.

[Andrey Konovalov]

On Tue, Aug 6, 2019 at 2:45 PM Oliver Neukum <one...@suse.com> wrote:
>
> Am Dienstag, den 30.07.2019, 02:38 -0700 schrieb syzbot:
> > Hello,
> >
> > syzbot found the following crash on:
> >
> > HEAD commit: 41550654 [UPSTREAM] KVM: x86: degrade WARN to pr_warn_rate..
> > git tree: kmsan
> > console output: https://syzkaller.appspot.com/x/log.txt?x=13e95183a00000
> > kernel config: https://syzkaller.appspot.com/x/.config?x=40511ad0c5945201
> > dashboard link: https://syzkaller.appspot.com/bug?extid=513e4d0985298538bf9b
> > compiler: clang version 9.0.0 (/home/glider/llvm/clang
> > 80fee25776c2fb61e74c1ecb1a523375c2500b69)
> > syz repro: https://syzkaller.appspot.com/x/repro.syz?x=17eafa1ba00000
> > C reproducer: https://syzkaller.appspot.com/x/repro.c?x=17b87983a00000
> >
> > IMPORTANT: if you fix the bug, please add the following tag to the commit:
> > Reported-by: syzbot+513e4d...@syzkaller.appspotmail.com
>
> #syz test: https://github.com/google/kasan.git 41550654

Hi Oliver,

For KMSAN bugs you'll need to use the kmsan tree (syz test:
https://github.com/google/kmsan.git COMMIT_ID). I've updated the
testing instructions some time ago to reflect this. Sorry for the
complexity, this is caused by USB fuzzing and KMSAN not being upstream
yet.

Thanks!

>
> From 6de76fa3df8aedc7a76dc0ecdea8308e38d4dccc Mon Sep 17 00:00:00 2001
> From: Oliver Neukum <one...@suse.com>
> Date: Tue, 6 Aug 2019 14:41:52 +0200
> Subject: [PATCH] pcan_usb_fd: zero out the common command buffer
>
> Lest we leak kernel memory to a device we better zero out buffers.
>
> Signed-off-by: Oliver Neukum <one...@suse.com>
> ---
> drivers/net/can/usb/peak_usb/pcan_usb_fd.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/net/can/usb/peak_usb/pcan_usb_fd.c b/drivers/net/can/usb/peak_usb/pcan_usb_fd.c
> index 34761c3a6286..47cc1ff5b88e 100644
> --- a/drivers/net/can/usb/peak_usb/pcan_usb_fd.c
> +++ b/drivers/net/can/usb/peak_usb/pcan_usb_fd.c
> @@ -841,7 +841,7 @@ static int pcan_usb_fd_init(struct peak_usb_device *dev)
> goto err_out;
>
> /* allocate command buffer once for all for the interface */
> - pdev->cmd_buffer_addr = kmalloc(PCAN_UFD_CMD_BUFFER_SIZE,
> + pdev->cmd_buffer_addr = kzalloc(PCAN_UFD_CMD_BUFFER_SIZE,
> GFP_KERNEL);
> if (!pdev->cmd_buffer_addr)
> goto err_out_1;
> --
> 2.16.4
>
>
>

> --
> You received this message because you are subscribed to the Google Groups "syzkaller-bugs" group.
> To unsubscribe from this group and stop receiving emails from it, send an email to syzkaller-bug...@googlegroups.com.

> To view this discussion on the web visit https://groups.google.com/d/msgid/syzkaller-bugs/1565095525.8136.22.camel%40suse.com.

[Oliver Neukum]

Am Dienstag, den 30.07.2019, 02:38 -0700 schrieb syzbot:

> Hello,
>
> syzbot found the following crash on:
>
> HEAD commit: 41550654 [UPSTREAM] KVM: x86: degrade WARN to pr_warn_rate..
> git tree: kmsan
> console output: https://syzkaller.appspot.com/x/log.txt?x=13e95183a00000
> kernel config: https://syzkaller.appspot.com/x/.config?x=40511ad0c5945201
> dashboard link: https://syzkaller.appspot.com/bug?extid=513e4d0985298538bf9b
> compiler: clang version 9.0.0 (/home/glider/llvm/clang
> 80fee25776c2fb61e74c1ecb1a523375c2500b69)
> syz repro: https://syzkaller.appspot.com/x/repro.syz?x=17eafa1ba00000
> C reproducer: https://syzkaller.appspot.com/x/repro.c?x=17b87983a00000
>
> IMPORTANT: if you fix the bug, please add the following tag to the commit:
> Reported-by: syzbot+513e4d...@syzkaller.appspotmail.com

#syz test: https://github.com/google/kmsan.git 41550654

[Alan Stern]

On Tue, 6 Aug 2019, Andrey Konovalov wrote:

> On Tue, Aug 6, 2019 at 2:45 PM Oliver Neukum <one...@suse.com> wrote:
> >
> > Am Dienstag, den 30.07.2019, 02:38 -0700 schrieb syzbot:
> > > Hello,
> > >
> > > syzbot found the following crash on:
> > >
> > > HEAD commit: 41550654 [UPSTREAM] KVM: x86: degrade WARN to pr_warn_rate..
> > > git tree: kmsan
> > > console output: https://syzkaller.appspot.com/x/log.txt?x=13e95183a00000
> > > kernel config: https://syzkaller.appspot.com/x/.config?x=40511ad0c5945201
> > > dashboard link: https://syzkaller.appspot.com/bug?extid=513e4d0985298538bf9b
> > > compiler: clang version 9.0.0 (/home/glider/llvm/clang
> > > 80fee25776c2fb61e74c1ecb1a523375c2500b69)
> > > syz repro: https://syzkaller.appspot.com/x/repro.syz?x=17eafa1ba00000
> > > C reproducer: https://syzkaller.appspot.com/x/repro.c?x=17b87983a00000
> > >
> > > IMPORTANT: if you fix the bug, please add the following tag to the commit:
> > > Reported-by: syzbot+513e4d...@syzkaller.appspotmail.com
> >
> > #syz test: https://github.com/google/kasan.git 41550654
>
> Hi Oliver,
>
> For KMSAN bugs you'll need to use the kmsan tree (syz test:
> https://github.com/google/kmsan.git COMMIT_ID). I've updated the
> testing instructions some time ago to reflect this. Sorry for the
> complexity, this is caused by USB fuzzing and KMSAN not being upstream
> yet.

Maybe you can fix the "git tree:" header in the bug report. It should
say "https://github.com/google/kmsan.git" instead of just "kmsan".

Alan Stern

[Andrey Konovalov]

Makes sense, will do, thanks!

>
> Alan Stern
>

[syzbot]

Hello,

syzbot has tested the proposed patch and the reproducer did not trigger
crash:

Reported-and-tested-by:
syzbot+513e4d...@syzkaller.appspotmail.com

Tested on:

commit: 41550654 [UPSTREAM] KVM: x86: degrade WARN to pr_warn_rate..

git tree: https://github.com/google/kmsan.git
kernel config: https://syzkaller.appspot.com/x/.config?x=40511ad0c5945201

compiler: clang version 9.0.0 (/home/glider/llvm/clang
80fee25776c2fb61e74c1ecb1a523375c2500b69)

patch: https://syzkaller.appspot.com/x/patch.diff?x=1170f88c600000

Note: testing is done by a robot and is best-effort only.