Re: [PATCH] net: usb: asix: init MAC address buffers

[Phong Tran]

Hello Dan,

On Mon, Jul 1, 2019 at 10:30 PM Dan Williams  wrote:
>
> On Mon, 2019-07-01 at 06:45 +0700, Phong Tran wrote:
> > This is for fixing bug KMSAN: uninit-value in ax88772_bind
> >
> > Tested by
> > https://groups.google.com/d/msg/syzkaller-bugs/aFQurGotng4/cFe9nxMCCwAJ
> >
> > Reported-by: syzbot+8a3fc6674bbc3978e...@syzkaller.appspotmail.com
> >
> > syzbot found the following crash on:
> >
> > HEAD commit:f75e4cfe kmsan: use kmsan_handle_urb() in urb.c
> > git tree:   kmsan
> > console output:
> > https://syzkaller.appspot.com/x/log.txt?x=136d720ea0
> > kernel config:
> > https://syzkaller.appspot.com/x/.config?x=602468164ccdc30a
> > dashboard link:
> > https://syzkaller.appspot.com/bug?extid=8a3fc6674bbc3978ed4e
> > compiler:   clang version 9.0.0 (/home/glider/llvm/clang
> > 06d00afa61eef8f7f501ebdb4e8612ea43ec2d78)
> > syz repro:
> > https://syzkaller.appspot.com/x/repro.syz?x=12788316a0
> > C reproducer:
> > https://syzkaller.appspot.com/x/repro.c?x=120359aaa0
> >
> > ==
> > BUG: KMSAN: uninit-value in is_valid_ether_addr
> > include/linux/etherdevice.h:200 [inline]
> > BUG: KMSAN: uninit-value in asix_set_netdev_dev_addr
> > drivers/net/usb/asix_devices.c:73 [inline]
> > BUG: KMSAN: uninit-value in ax88772_bind+0x93d/0x11e0
> > drivers/net/usb/asix_devices.c:724
> > CPU: 0 PID: 3348 Comm: kworker/0:2 Not tainted 5.1.0+ #1
> > 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+0x130/0x2a0 mm/kmsan/kmsan.c:622
> >   __msan_warning+0x75/0xe0 mm/kmsan/kmsan_instr.c:310
> >   is_valid_ether_addr include/linux/etherdevice.h:200 [inline]
> >   asix_set_netdev_dev_addr drivers/net/usb/asix_devices.c:73 [inline]
> >   ax88772_bind+0x93d/0x11e0 drivers/net/usb/asix_devices.c:724
> >   usbnet_probe+0x10f5/0x3940 drivers/net/usb/usbnet.c:1728
> >   usb_probe_interface+0xd66/0x1320 drivers/usb/core/driver.c:361
> >   really_probe+0xdae/0x1d80 drivers/base/dd.c:513
> >   driver_probe_device+0x1b3/0x4f0 drivers/base/dd.c:671
> >   __device_attach_driver+0x5b8/0x790 drivers/base/dd.c:778
> >   bus_for_each_drv+0x28e/0x3b0 drivers/base/bus.c:454
> >   __device_attach+0x454/0x730 drivers/base/dd.c:844
> >   device_initial_probe+0x4a/0x60 drivers/base/dd.c:891
> >   bus_probe_device+0x137/0x390 drivers/base/bus.c:514
> >   device_add+0x288d/0x30e0 drivers/base/core.c:2106
> >   usb_set_configuration+0x30dc/0x3750 drivers/usb/core/message.c:2027
> >   generic_probe+0xe7/0x280 drivers/usb/core/generic.c:210
> >   usb_probe_device+0x14c/0x200 drivers/usb/core/driver.c:266
> >   really_probe+0xdae/0x1d80 drivers/base/dd.c:513
> >   driver_probe_device+0x1b3/0x4f0 drivers/base/dd.c:671
> >   __device_attach_driver+0x5b8/0x790 drivers/base/dd.c:778
> >   bus_for_each_drv+0x28e/0x3b0 drivers/base/bus.c:454
> >   __device_attach+0x454/0x730 drivers/base/dd.c:844
> >   device_initial_probe+0x4a/0x60 drivers/base/dd.c:891
> >   bus_probe_device+0x137/0x390 drivers/base/bus.c:514
> >   device_add+0x288d/0x30e0 drivers/base/core.c:2106
> >   usb_new_device+0x23e5/0x2ff0 drivers/usb/core/hub.c:2534
> >   hub_port_connect drivers/usb/core/hub.c:5089 [inline]
> >   hub_port_connect_change drivers/usb/core/hub.c:5204 [inline]
> >   port_event drivers/usb/core/hub.c:5350 [inline]
> >   hub_event+0x48d1/0x7290 drivers/usb/core/hub.c:5432
> >   process_one_work+0x1572/0x1f00 kernel/workqueue.c:2269
> >   process_scheduled_works kernel/workqueue.c:2331 [inline]
> >   worker_thread+0x189c/0x2460 kernel/workqueue.c:2417
> >   kthread+0x4b5/0x4f0 kernel/kthread.c:254
> >   ret_from_fork+0x35/0x40 arch/x86/entry/entry_64.S:355
> >
> > Signed-off-by: Phong Tran 
> > ---
> >  drivers/net/usb/asix_devices.c | 3 +++
> >  1 file changed, 3 insertions(+)
> >
> > diff --git a/drivers/net/usb/asix_devices.c
> > b/drivers/net/usb/asix_devices.c
> > index c9bc96310ed4..f514d19316b1 100644
> > --- a/drivers/net/usb/asix_devices.c
> > +++ b/drivers/net/usb/asix_devices.c
> > @@ -230,6 +230,7 @@ static int ax88172_bind(struct usbnet *dev,
> > struct usb_interface *intf)
> >   int i;
> >   unsigned long gpio_bits = dev->driver_info->data;
> >
> > + memset(buf, 0, sizeof(buf));
>
> For array variables defined in the function itself, isn't this usually
> done with:
>
>  int ret = 0;
> -u8 buf[ETH_ALEN];
> +u8 buf[ETH_ALEN] = {0};
>  int i;
>  unsigned long gpio_bits = dev->driver_info->data;
>
> eg make the compiler do it (though maybe it's smart enough to elide the
> memset, I don't know). See drivers/net/ethernet/intel/igb/e1000_mac.c
> for an example.
>

Thank suggestion, applied in v2 without using memset().

Phong

Re: [PATCH] net: usb: asix: init MAC address buffers

[Dan Williams]

On Mon, 2019-07-01 at 06:45 +0700, Phong Tran wrote:
> This is for fixing bug KMSAN: uninit-value in ax88772_bind
> 
> Tested by
> https://groups.google.com/d/msg/syzkaller-bugs/aFQurGotng4/cFe9nxMCCwAJ
> 
> Reported-by: syzbot+8a3fc6674bbc3978e...@syzkaller.appspotmail.com
> 
> syzbot found the following crash on:
> 
> HEAD commit:f75e4cfe kmsan: use kmsan_handle_urb() in urb.c
> git tree:   kmsan
> console output: 
> https://syzkaller.appspot.com/x/log.txt?x=136d720ea0
> kernel config:
> https://syzkaller.appspot.com/x/.config?x=602468164ccdc30a
> dashboard link:
> https://syzkaller.appspot.com/bug?extid=8a3fc6674bbc3978ed4e
> compiler:   clang version 9.0.0 (/home/glider/llvm/clang
> 06d00afa61eef8f7f501ebdb4e8612ea43ec2d78)
> syz repro:
> https://syzkaller.appspot.com/x/repro.syz?x=12788316a0
> C reproducer:   
> https://syzkaller.appspot.com/x/repro.c?x=120359aaa0
> 
> ==
> BUG: KMSAN: uninit-value in is_valid_ether_addr
> include/linux/etherdevice.h:200 [inline]
> BUG: KMSAN: uninit-value in asix_set_netdev_dev_addr
> drivers/net/usb/asix_devices.c:73 [inline]
> BUG: KMSAN: uninit-value in ax88772_bind+0x93d/0x11e0
> drivers/net/usb/asix_devices.c:724
> CPU: 0 PID: 3348 Comm: kworker/0:2 Not tainted 5.1.0+ #1
> 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+0x130/0x2a0 mm/kmsan/kmsan.c:622
>   __msan_warning+0x75/0xe0 mm/kmsan/kmsan_instr.c:310
>   is_valid_ether_addr include/linux/etherdevice.h:200 [inline]
>   asix_set_netdev_dev_addr drivers/net/usb/asix_devices.c:73 [inline]
>   ax88772_bind+0x93d/0x11e0 drivers/net/usb/asix_devices.c:724
>   usbnet_probe+0x10f5/0x3940 drivers/net/usb/usbnet.c:1728
>   usb_probe_interface+0xd66/0x1320 drivers/usb/core/driver.c:361
>   really_probe+0xdae/0x1d80 drivers/base/dd.c:513
>   driver_probe_device+0x1b3/0x4f0 drivers/base/dd.c:671
>   __device_attach_driver+0x5b8/0x790 drivers/base/dd.c:778
>   bus_for_each_drv+0x28e/0x3b0 drivers/base/bus.c:454
>   __device_attach+0x454/0x730 drivers/base/dd.c:844
>   device_initial_probe+0x4a/0x60 drivers/base/dd.c:891
>   bus_probe_device+0x137/0x390 drivers/base/bus.c:514
>   device_add+0x288d/0x30e0 drivers/base/core.c:2106
>   usb_set_configuration+0x30dc/0x3750 drivers/usb/core/message.c:2027
>   generic_probe+0xe7/0x280 drivers/usb/core/generic.c:210
>   usb_probe_device+0x14c/0x200 drivers/usb/core/driver.c:266
>   really_probe+0xdae/0x1d80 drivers/base/dd.c:513
>   driver_probe_device+0x1b3/0x4f0 drivers/base/dd.c:671
>   __device_attach_driver+0x5b8/0x790 drivers/base/dd.c:778
>   bus_for_each_drv+0x28e/0x3b0 drivers/base/bus.c:454
>   __device_attach+0x454/0x730 drivers/base/dd.c:844
>   device_initial_probe+0x4a/0x60 drivers/base/dd.c:891
>   bus_probe_device+0x137/0x390 drivers/base/bus.c:514
>   device_add+0x288d/0x30e0 drivers/base/core.c:2106
>   usb_new_device+0x23e5/0x2ff0 drivers/usb/core/hub.c:2534
>   hub_port_connect drivers/usb/core/hub.c:5089 [inline]
>   hub_port_connect_change drivers/usb/core/hub.c:5204 [inline]
>   port_event drivers/usb/core/hub.c:5350 [inline]
>   hub_event+0x48d1/0x7290 drivers/usb/core/hub.c:5432
>   process_one_work+0x1572/0x1f00 kernel/workqueue.c:2269
>   process_scheduled_works kernel/workqueue.c:2331 [inline]
>   worker_thread+0x189c/0x2460 kernel/workqueue.c:2417
>   kthread+0x4b5/0x4f0 kernel/kthread.c:254
>   ret_from_fork+0x35/0x40 arch/x86/entry/entry_64.S:355
> 
> Signed-off-by: Phong Tran 
> ---
>  drivers/net/usb/asix_devices.c | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/drivers/net/usb/asix_devices.c
> b/drivers/net/usb/asix_devices.c
> index c9bc96310ed4..f514d19316b1 100644
> --- a/drivers/net/usb/asix_devices.c
> +++ b/drivers/net/usb/asix_devices.c
> @@ -230,6 +230,7 @@ static int ax88172_bind(struct usbnet *dev,
> struct usb_interface *intf)
>   int i;
>   unsigned long gpio_bits = dev->driver_info->data;
>  
> + memset(buf, 0, sizeof(buf));

For array variables defined in the function itself, isn't this usually
done with:

 int ret = 0;
-u8 buf[ETH_ALEN];
+u8 buf[ETH_ALEN] = {0};
 int i;
 unsigned long gpio_bits = dev->driver_info->data;

eg make the compiler do it (though maybe it's smart enough to elide the
memset, I don't know). See drivers/net/ethernet/intel/igb/e1000_mac.c
for an example.

Dan

>   usbnet_get_endpoints(dev,intf);
>  
>   /* Toggle the GPIOs in a manufacturer/model specific way */
> @@ -681,6 +682,7 @@ static int ax88772_bind(struct usbnet *dev,
> struct usb_interface *intf)
>   u32 phyid;
>   struct asix_common_private *priv;
>  
> + memset(buf, 0, sizeof(buf));
>   usbnet_get_endpoints(dev, intf);
>  
>   /* Maybe the boot loader passed the MAC 

[PATCH] net: usb: asix: init MAC address buffers

[Phong Tran]

This is for fixing bug KMSAN: uninit-value in ax88772_bind

Tested by
https://groups.google.com/d/msg/syzkaller-bugs/aFQurGotng4/cFe9nxMCCwAJ

Reported-by: syzbot+8a3fc6674bbc3978e...@syzkaller.appspotmail.com

syzbot found the following crash on:

HEAD commit:f75e4cfe kmsan: use kmsan_handle_urb() in urb.c
git tree:   kmsan
console output: https://syzkaller.appspot.com/x/log.txt?x=136d720ea0
kernel config:
https://syzkaller.appspot.com/x/.config?x=602468164ccdc30a
dashboard link:
https://syzkaller.appspot.com/bug?extid=8a3fc6674bbc3978ed4e
compiler:   clang version 9.0.0 (/home/glider/llvm/clang
06d00afa61eef8f7f501ebdb4e8612ea43ec2d78)
syz repro:
https://syzkaller.appspot.com/x/repro.syz?x=12788316a0
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=120359aaa0

==
BUG: KMSAN: uninit-value in is_valid_ether_addr
include/linux/etherdevice.h:200 [inline]
BUG: KMSAN: uninit-value in asix_set_netdev_dev_addr
drivers/net/usb/asix_devices.c:73 [inline]
BUG: KMSAN: uninit-value in ax88772_bind+0x93d/0x11e0
drivers/net/usb/asix_devices.c:724
CPU: 0 PID: 3348 Comm: kworker/0:2 Not tainted 5.1.0+ #1
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+0x130/0x2a0 mm/kmsan/kmsan.c:622
  __msan_warning+0x75/0xe0 mm/kmsan/kmsan_instr.c:310
  is_valid_ether_addr include/linux/etherdevice.h:200 [inline]
  asix_set_netdev_dev_addr drivers/net/usb/asix_devices.c:73 [inline]
  ax88772_bind+0x93d/0x11e0 drivers/net/usb/asix_devices.c:724
  usbnet_probe+0x10f5/0x3940 drivers/net/usb/usbnet.c:1728
  usb_probe_interface+0xd66/0x1320 drivers/usb/core/driver.c:361
  really_probe+0xdae/0x1d80 drivers/base/dd.c:513
  driver_probe_device+0x1b3/0x4f0 drivers/base/dd.c:671
  __device_attach_driver+0x5b8/0x790 drivers/base/dd.c:778
  bus_for_each_drv+0x28e/0x3b0 drivers/base/bus.c:454
  __device_attach+0x454/0x730 drivers/base/dd.c:844
  device_initial_probe+0x4a/0x60 drivers/base/dd.c:891
  bus_probe_device+0x137/0x390 drivers/base/bus.c:514
  device_add+0x288d/0x30e0 drivers/base/core.c:2106
  usb_set_configuration+0x30dc/0x3750 drivers/usb/core/message.c:2027
  generic_probe+0xe7/0x280 drivers/usb/core/generic.c:210
  usb_probe_device+0x14c/0x200 drivers/usb/core/driver.c:266
  really_probe+0xdae/0x1d80 drivers/base/dd.c:513
  driver_probe_device+0x1b3/0x4f0 drivers/base/dd.c:671
  __device_attach_driver+0x5b8/0x790 drivers/base/dd.c:778
  bus_for_each_drv+0x28e/0x3b0 drivers/base/bus.c:454
  __device_attach+0x454/0x730 drivers/base/dd.c:844
  device_initial_probe+0x4a/0x60 drivers/base/dd.c:891
  bus_probe_device+0x137/0x390 drivers/base/bus.c:514
  device_add+0x288d/0x30e0 drivers/base/core.c:2106
  usb_new_device+0x23e5/0x2ff0 drivers/usb/core/hub.c:2534
  hub_port_connect drivers/usb/core/hub.c:5089 [inline]
  hub_port_connect_change drivers/usb/core/hub.c:5204 [inline]
  port_event drivers/usb/core/hub.c:5350 [inline]
  hub_event+0x48d1/0x7290 drivers/usb/core/hub.c:5432
  process_one_work+0x1572/0x1f00 kernel/workqueue.c:2269
  process_scheduled_works kernel/workqueue.c:2331 [inline]
  worker_thread+0x189c/0x2460 kernel/workqueue.c:2417
  kthread+0x4b5/0x4f0 kernel/kthread.c:254
  ret_from_fork+0x35/0x40 arch/x86/entry/entry_64.S:355

Signed-off-by: Phong Tran 
---
 drivers/net/usb/asix_devices.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/net/usb/asix_devices.c b/drivers/net/usb/asix_devices.c
index c9bc96310ed4..f514d19316b1 100644
--- a/drivers/net/usb/asix_devices.c
+++ b/drivers/net/usb/asix_devices.c
@@ -230,6 +230,7 @@ static int ax88172_bind(struct usbnet *dev, struct 
usb_interface *intf)
int i;
unsigned long gpio_bits = dev->driver_info->data;
 
+   memset(buf, 0, sizeof(buf));
usbnet_get_endpoints(dev,intf);
 
/* Toggle the GPIOs in a manufacturer/model specific way */
@@ -681,6 +682,7 @@ static int ax88772_bind(struct usbnet *dev, struct 
usb_interface *intf)
u32 phyid;
struct asix_common_private *priv;
 
+   memset(buf, 0, sizeof(buf));
usbnet_get_endpoints(dev, intf);
 
/* Maybe the boot loader passed the MAC address via device tree */
@@ -1063,6 +1065,7 @@ static int ax88178_bind(struct usbnet *dev, struct 
usb_interface *intf)
int ret;
u8 buf[ETH_ALEN];
 
+   memset(buf, 0, sizeof(buf));
usbnet_get_endpoints(dev,intf);
 
/* Get the MAC address */
-- 
2.11.0