KMSAN: kernel-usb-infoleak in pcan_usb_pro_send_req

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+513e4d0985298538bf9b@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 syzkaller@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

Re: KMSAN: kernel-usb-infoleak in pcan_usb_pro_send_req

[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+513e4d0985298538bf9b@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

Re: KMSAN: kernel-usb-infoleak in pcan_usb_pro_send_req

[Andrey Konovalov]

On Tue, Jul 30, 2019 at 4:17 PM Alan Stern <stern@rowland.harvard.edu> wrote:
>
> 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+513e4d0985298538bf9b@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?

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

>
> Alan Stern
>

Re: KMSAN: kernel-usb-infoleak in pcan_usb_pro_send_req

[Andrey Konovalov]

On Tue, Jul 30, 2019 at 4:20 PM Andrey Konovalov <andreyknvl@google.com> wrote:
>
> On Tue, Jul 30, 2019 at 4:17 PM Alan Stern <stern@rowland.harvard.edu> wrote:
> >
> > 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+513e4d0985298538bf9b@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?
>
> That means that the kernel put some uninitialized data into a request
> that was sent to a USB device.

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
> >

Re: KMSAN: kernel-usb-infoleak in pcan_usb_pro_send_req

[Alexander Potapenko]

On Tue, Jul 30, 2019 at 4:22 PM 'Andrey Konovalov' via syzkaller-bugs
<syzkaller-bugs@googlegroups.com> wrote:
>
> On Tue, Jul 30, 2019 at 4:20 PM Andrey Konovalov <andreyknvl@google.com> wrote:
> >
> > On Tue, Jul 30, 2019 at 4:17 PM Alan Stern <stern@rowland.harvard.edu> wrote:
> > >
> > > 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+513e4d0985298538bf9b@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?
> >
> > That means that the kernel put some uninitialized data into a request
> > that was sent to a USB device.
>
> Here's a better report for this bug:
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-bugs+unsubscribe@googlegroups.com.
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-- 
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

Re: KMSAN: kernel-usb-infoleak in pcan_usb_pro_send_req

[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+513e4d0985298538bf9b@syzkaller.appspotmail.com

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

From 6de76fa3df8aedc7a76dc0ecdea8308e38d4dccc Mon Sep 17 00:00:00 2001
From: Oliver Neukum <oneukum@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 <oneukum@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

Re: Re: KMSAN: kernel-usb-infoleak in pcan_usb_pro_send_req

[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+513e4d0985298538bf9b@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.


>  From 6de76fa3df8aedc7a76dc0ecdea8308e38d4dccc Mon Sep 17 00:00:00 2001
> From: Oliver Neukum <oneukum@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 <oneukum@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

Re: KMSAN: kernel-usb-infoleak in pcan_usb_pro_send_req

[Andrey Konovalov]

On Tue, Aug 6, 2019 at 2:45 PM Oliver Neukum <oneukum@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+513e4d0985298538bf9b@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 <oneukum@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 <oneukum@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
>
>
>
> --
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Re: KMSAN: kernel-usb-infoleak in pcan_usb_pro_send_req

[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+513e4d0985298538bf9b@syzkaller.appspotmail.com

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

From 6de76fa3df8aedc7a76dc0ecdea8308e38d4dccc Mon Sep 17 00:00:00 2001
From: Oliver Neukum <oneukum@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 <oneukum@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;

Re: KMSAN: kernel-usb-infoleak in pcan_usb_pro_send_req

[Alan Stern]

On Tue, 6 Aug 2019, Andrey Konovalov wrote:

> On Tue, Aug 6, 2019 at 2:45 PM Oliver Neukum <oneukum@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+513e4d0985298538bf9b@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

Re: KMSAN: kernel-usb-infoleak in pcan_usb_pro_send_req

[Andrey Konovalov]

On Tue, Aug 6, 2019 at 3:59 PM Alan Stern <stern@rowland.harvard.edu> wrote:
>
> On Tue, 6 Aug 2019, Andrey Konovalov wrote:
>
> > On Tue, Aug 6, 2019 at 2:45 PM Oliver Neukum <oneukum@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+513e4d0985298538bf9b@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".

Makes sense, will do, thanks!

>
> Alan Stern
>

Re: KMSAN: kernel-usb-infoleak in pcan_usb_pro_send_req

[syzbot]

Hello,

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

Reported-and-tested-by:  
syzbot+513e4d0985298538bf9b@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.