KMSAN: uninit-value in rt2500usb_probe

KMSAN: uninit-value in rt2500usb_probe_hw
Status: upstream: reported C repro on 2019/09/30 22:39
Reported-by: syzbot+35c80b2190255a410f66@syzkaller.appspotmail.com
First crash: 192d, last: 137d

Sample crash report:

usb 1-1: config 0 descriptor??
usb 1-1: reset high-speed USB device number 2 using dummy_hcd
usb 1-1: device descriptor read/64, error -71
usb 1-1: Using ep0 maxpacket: 16
ieee80211 phy3: rt2x00usb_vendor_request: Error - Vendor Request 0x09 failed for offset 0x0000 with error -71
ieee80211 phy3: rt2x00_set_chip: Info - Chipset detected - rt: 2570, rf: 0000, rev: 8771
==================================================================
BUG: KMSAN: uninit-value in rt2500usb_init_eeprom drivers/net/wireless/ralink/rt2x00/rt2500usb.c:1443 [inline]
BUG: KMSAN: uninit-value in rt2500usb_probe_hw+0xb5e/0x22a0 drivers/net/wireless/ralink/rt2x00/rt2500usb.c:1757
CPU: 0 PID: 3369 Comm: kworker/0:2 Not tainted 5.3.0-rc7+ #0
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
 rt2500usb_init_eeprom drivers/net/wireless/ralink/rt2x00/rt2500usb.c:1443 [inline]
 rt2500usb_probe_hw+0xb5e/0x22a0 drivers/net/wireless/ralink/rt2x00/rt2500usb.c:1757
 rt2x00lib_probe_dev+0xba9/0x3260 drivers/net/wireless/ralink/rt2x00/rt2x00dev.c:1427
 rt2x00usb_probe+0x7ae/0xf60 drivers/net/wireless/ralink/rt2x00/rt2x00usb.c:842
 rt2500usb_probe+0x50/0x60 drivers/net/wireless/ralink/rt2x00/rt2500usb.c:1966
 usb_probe_interface+0xd19/0x1310 drivers/usb/core/driver.c:361
 really_probe+0x1373/0x1dc0 drivers/base/dd.c:552
 driver_probe_device+0x1ba/0x510 drivers/base/dd.c:709
 __device_attach_driver+0x5b8/0x790 drivers/base/dd.c:816
 bus_for_each_drv+0x28e/0x3b0 drivers/base/bus.c:454
 __device_attach+0x489/0x750 drivers/base/dd.c:882
 device_initial_probe+0x4a/0x60 drivers/base/dd.c:929
 bus_probe_device+0x131/0x390 drivers/base/bus.c:514
 device_add+0x25b5/0x2df0 drivers/base/core.c:2165
 usb_set_configuration+0x309f/0x3710 drivers/usb/core/message.c:2027
 generic_probe+0xe7/0x280 drivers/usb/core/generic.c:210
 usb_probe_device+0x146/0x200 drivers/usb/core/driver.c:266
 really_probe+0x1373/0x1dc0 drivers/base/dd.c:552
 driver_probe_device+0x1ba/0x510 drivers/base/dd.c:709
 __device_attach_driver+0x5b8/0x790 drivers/base/dd.c:816
 bus_for_each_drv+0x28e/0x3b0 drivers/base/bus.c:454
 __device_attach+0x489/0x750 drivers/base/dd.c:882
 device_initial_probe+0x4a/0x60 drivers/base/dd.c:929
 bus_probe_device+0x131/0x390 drivers/base/bus.c:514
 device_add+0x25b5/0x2df0 drivers/base/core.c:2165
 usb_new_device+0x23e5/0x2fb0 drivers/usb/core/hub.c:2536
 hub_port_connect drivers/usb/core/hub.c:5098 [inline]
 hub_port_connect_change drivers/usb/core/hub.c:5213 [inline]
 port_event drivers/usb/core/hub.c:5359 [inline]
 hub_event+0x581d/0x72f0 drivers/usb/core/hub.c:5441
 process_one_work+0x1572/0x1ef0 kernel/workqueue.c:2269
 worker_thread+0x111b/0x2460 kernel/workqueue.c:2415
 kthread+0x4b5/0x4f0 kernel/kthread.c:256
 ret_from_fork+0x35/0x40 arch/x86/entry/entry_64.S:355

Local variable description: ----reg.i.i@rt2500usb_probe_hw
Variable was created at:
 rt2500usb_register_read drivers/net/wireless/ralink/rt2x00/rt2500usb.c:51 [inline]
 rt2500usb_init_eeprom drivers/net/wireless/ralink/rt2x00/rt2500usb.c:1440 [inline]
 rt2500usb_probe_hw+0x774/0x22a0 drivers/net/wireless/ralink/rt2x00/rt2500usb.c:1757
 rt2x00lib_probe_dev+0xba9/0x3260 drivers/net/wireless/ralink/rt2x00/rt2x00dev.c:1427
==================================================================

Crashes (8):
Manager	Time	Kernel	Commit	Syzkaller	Config	Log	Report	Syz repro	C repro	Maintainers
ci-upstream-kmsan-gce	2019/09/18 10:10	https://github.com/google/kmsan.git master	cebbfdbc	03e0d245	.config	log	report	syz	C	davem@davemloft.net, helmut.schaa@googlemail.com, kvalo@codeaurora.org, linux-kernel@vger.kernel.org, linux-wireless@vger.kernel.org, netdev@vger.kernel.org, sgruszka@redhat.com
ci-upstream-kmsan-gce	2019/10/07 05:16	https://github.com/google/kmsan.git master	1e76a3e5	f3f7d9c8	.config	log	report			davem@davemloft.net, helmut.schaa@googlemail.com, kvalo@codeaurora.org, linux-kernel@vger.kernel.org, linux-wireless@vger.kernel.org, netdev@vger.kernel.org, sgruszka@redhat.com
ci-upstream-kmsan-gce	2019/10/06 23:49	https://github.com/google/kmsan.git master	1e76a3e5	f3f7d9c8	.config	log	report			davem@davemloft.net, helmut.schaa@googlemail.com, kvalo@codeaurora.org, linux-kernel@vger.kernel.org, linux-wireless@vger.kernel.org, netdev@vger.kernel.org, sgruszka@redhat.com
ci-upstream-kmsan-gce	2019/10/06 07:17	https://github.com/google/kmsan.git master	1e76a3e5	f3f7d9c8	.config	log	report			davem@davemloft.net, helmut.schaa@googlemail.com, kvalo@codeaurora.org, linux-kernel@vger.kernel.org, linux-wireless@vger.kernel.org, netdev@vger.kernel.org, sgruszka@redhat.com
ci-upstream-kmsan-gce	2019/10/06 03:05	https://github.com/google/kmsan.git master	1e76a3e5	f3f7d9c8	.config	log	report			davem@davemloft.net, helmut.schaa@googlemail.com, kvalo@codeaurora.org, linux-kernel@vger.kernel.org, linux-wireless@vger.kernel.org, netdev@vger.kernel.org, sgruszka@redhat.com
ci-upstream-kmsan-gce	2019/09/28 14:27	https://github.com/google/kmsan.git master	124037e0	eb6b9855	.config	log	report			davem@davemloft.net, helmut.schaa@googlemail.com, kvalo@codeaurora.org, linux-kernel@vger.kernel.org, linux-wireless@vger.kernel.org, netdev@vger.kernel.org, sgruszka@redhat.com
ci-upstream-kmsan-gce	2019/09/18 04:14	https://github.com/google/kmsan.git master	cebbfdbc	03e0d245	.config	log	report			davem@davemloft.net, helmut.schaa@googlemail.com, kvalo@codeaurora.org, linux-kernel@vger.kernel.org, linux-wireless@vger.kernel.org, netdev@vger.kernel.org, sgruszka@redhat.com
ci-upstream-kmsan-gce	2019/08/13 04:31	https://github.com/google/kmsan.git master	61ccdad1	8620c2c2	.config	log	report			davem@davemloft.net, helmut.schaa@googlemail.com, kvalo@codeaurora.org, linux-kernel@vger.kernel.org, linux-wireless@vger.kernel.org, netdev@vger.kernel.org, sgruszka@redhat.com