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+8a3fc6674bbc3978ed4e@xxxxxxxxxxxxxxxxxxxxxxxxx > > 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=136d720ea00000 > 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=12788316a00000 > C reproducer: > https://syzkaller.appspot.com/x/repro.c?x=120359aaa00000 > > ================================================================== > 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 <tranmanphong@xxxxxxxxx> > --- > 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 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 */
