Re: KMSAN: uninit-value in friio_power_ctrl

[syzbot]

syzbot has found a reproducer for the following crash on:

HEAD commit:    4009f3cf kmsan: slub: fix a compilation warning by moving ..
git tree:       kmsan
console output: https://syzkaller.appspot.com/x/log.txt?x=17f85018600000
kernel config:  https://syzkaller.appspot.com/x/.config?x=40511ad0c5945201
dashboard link: https://syzkaller.appspot.com/bug?extid=9e6bf7282557bd1fc80d
compiler:       clang version 9.0.0 (/home/glider/llvm/clang  
80fee25776c2fb61e74c1ecb1a523375c2500b69)
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=114535c4600000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=16236437a00000

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+9e6bf7282557bd1fc80d@xxxxxxxxxxxxxxxxxxxxxxxxx

usb 1-1: New USB device found, idVendor=7a69, idProduct=0001,  
bcdDevice=19.36
usb 1-1: New USB device strings: Mfr=0, Product=0, SerialNumber=0
usb 1-1: config 0 descriptor??
usb 1-1: dvb_usb_v2: found a '774 Friio White ISDB-T USB2.0' in warm state
==================================================================
BUG: KMSAN: uninit-value in friio_reset  
drivers/media/usb/dvb-usb-v2/gl861.c:433 [inline]
BUG: KMSAN: uninit-value in friio_power_ctrl+0xb3e/0x1a70  
drivers/media/usb/dvb-usb-v2/gl861.c:482
CPU: 0 PID: 12 Comm: kworker/0:1 Not tainted 5.2.0-rc4+ #12
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
 friio_reset drivers/media/usb/dvb-usb-v2/gl861.c:433 [inline]
 friio_power_ctrl+0xb3e/0x1a70 drivers/media/usb/dvb-usb-v2/gl861.c:482
 dvb_usbv2_device_power_ctrl  
drivers/media/usb/dvb-usb-v2/dvb_usb_core.c:540 [inline]
 dvb_usbv2_init drivers/media/usb/dvb-usb-v2/dvb_usb_core.c:853 [inline]
 dvb_usbv2_probe+0xd3d/0x5dd0  
drivers/media/usb/dvb-usb-v2/dvb_usb_core.c:980
 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
 bus_probe_device+0x131/0x390 drivers/base/bus.c:514
 device_add+0x25b5/0x2df0 drivers/base/core.c:2111
 usb_set_configuration+0x309f/0x3710 drivers/usb/core/message.c:2027
 ? __ms