KMSAN: uninit-value in mii_nway

KMSAN: uninit-value in mii_nway_restart
Status: upstream: reported C repro on 2019/06/04 10:32
Reported-by: syzbot+1f53a30781af65d2c955@syzkaller.appspotmail.com
First crash: 839d, last: 203d

Patch testing requests:
Created	Duration	User	Patch	Repo	Result
2020/09/20 16:36	19m	anant.thazhemadam@gmail.com		https://github.com/google/kmsan.git master	OK

Sample crash report:

ax88179_178a 1-1:0.239 (unnamed net_device) (uninitialized): Failed to write reg index 0x000e: -71
ax88179_178a 1-1:0.239 (unnamed net_device) (uninitialized): Failed to write reg index 0x000d: -71
ax88179_178a 1-1:0.239 (unnamed net_device) (uninitialized): Failed to write reg index 0x000e: -71
ax88179_178a 1-1:0.239 (unnamed net_device) (uninitialized): Failed to read reg index 0x0000: -71
==================================================================
BUG: KMSAN: uninit-value in mii_nway_restart+0x141/0x260 drivers/net/mii.c:467
CPU: 0 PID: 2902 Comm: kworker/0:2 Not tainted 5.3.0-rc3+ #17
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
 mii_nway_restart+0x141/0x260 drivers/net/mii.c:467
 ax88179_bind+0xee3/0x1a10 drivers/net/usb/ax88179_178a.c:1317
 usbnet_probe+0x10ae/0x3960 drivers/net/usb/usbnet.c:1722
 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:2114
 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:2114
 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
 process_scheduled_works kernel/workqueue.c:2331 [inline]
 worker_thread+0x189c/0x2460 kernel/workqueue.c:2417
 kthread+0x4b5/0x4f0 kernel/kthread.c:256
 ret_from_fork+0x35/0x40 arch/x86/entry/entry_64.S:355

Local variable description: ----buf.i@ax88179_mdio_read
Variable was created at:
 __ax88179_read_cmd include/linux/netdevice.h:2180 [inline]
 ax88179_read_cmd drivers/net/usb/ax88179_178a.c:299 [inline]
 ax88179_mdio_read+0x7b/0x240 drivers/net/usb/ax88179_178a.c:357
 mii_nway_restart+0xcf/0x260 drivers/net/mii.c:465
==================================================================

Crashes (98):
Manager	Time	Kernel	Commit	Syzkaller	Config	Log	Report	Syz repro	C repro	VM info	Title
ci-upstream-kmsan-gce	2019/08/12 00:31	https://github.com/google/kmsan.git master	61ccdad1fcdf	acb51638	.config	log	report	syz	C
ci-upstream-kmsan-gce	2019/08/11 10:37	https://github.com/google/kmsan.git master	61ccdad1fcdf	acb51638	.config	log	report	syz	C
ci-upstream-kmsan-gce	2019/08/09 17:23	https://github.com/google/kmsan.git master	61ccdad1fcdf	ede31a9b	.config	log	report	syz	C
ci-upstream-kmsan-gce	2019/07/28 02:28	https://github.com/google/kmsan.git master	beaab8a31e0d	c85e1c5b	.config	log	report	syz	C
ci-upstream-kmsan-gce	2019/07/02 09:57	https://github.com/google/kmsan.git master	41550654dedf	cccc4302	.config	log	report	syz	C
ci-upstream-kmsan-gce	2019/06/04 08:56	https://github.com/google/kmsan.git master	f75e4cfea97f	ce07a7ae	.config	log	report	syz	C
ci-upstream-kmsan-gce	2021/02/28 13:20	https://github.com/google/kmsan.git master	29ad81a1074a	4c37c133	.config	log	report			info	KMSAN: uninit-value in mii_nway_restart
ci-upstream-kmsan-gce	2021/02/26 23:42	https://github.com/google/kmsan.git master	29ad81a1074a	4c37c133	.config	log	report			info	KMSAN: uninit-value in mii_nway_restart
ci-upstream-kmsan-gce	2019/10/28 14:47	https://github.com/google/kmsan.git master	d86c15562d02	25bb509e	.config	log	report
ci-upstream-kmsan-gce	2019/10/27 20:23	https://github.com/google/kmsan.git master	d86c15562d02	25bb509e	.config	log	report
ci-upstream-kmsan-gce	2019/10/27 03:35	https://github.com/google/kmsan.git master	d86c15562d02	25bb509e	.config	log	report
ci-upstream-kmsan-gce	2019/10/26 20:29	https://github.com/google/kmsan.git master	d86c15562d02	25bb509e	.config	log	report
ci-upstream-kmsan-gce	2019/10/25 22:39	https://github.com/google/kmsan.git master	d86c15562d02	c2e837da	.config	log	report
ci-upstream-kmsan-gce	2019/10/25 17:57	https://github.com/google/kmsan.git master	d86c15562d02	c2e837da	.config	log	report
ci-upstream-kmsan-gce	2019/10/24 22:36	https://github.com/google/kmsan.git master	d86c15562d02	d01bb02a	.config	log	report
ci-upstream-kmsan-gce	2019/10/23 18:13	https://github.com/google/kmsan.git master	3c8ca70889aa	b602d64b	.config	log	report
ci-upstream-kmsan-gce	2019/10/23 11:08	https://github.com/google/kmsan.git master	3c8ca70889aa	d0686497	.config	log	report
ci-upstream-kmsan-gce	2019/10/23 06:24	https://github.com/google/kmsan.git master	3c8ca70889aa	d0686497	.config	log	report
ci-upstream-kmsan-gce	2019/10/22 18:38	https://github.com/google/kmsan.git master	3c8ca70889aa	5681358a	.config	log	report
ci-upstream-kmsan-gce	2019/10/20 11:06	https://github.com/google/kmsan.git master	3c8ca70889aa	8c88c9c1	.config	log	report
ci-upstream-kmsan-gce	2019/10/20 04:02	https://github.com/google/kmsan.git master	3c8ca70889aa	8c88c9c1	.config	log	report
ci-upstream-kmsan-gce	2019/10/19 22:56	https://github.com/google/kmsan.git master	3c8ca70889aa	8c88c9c1	.config	log	report
ci-upstream-kmsan-gce	2019/10/19 19:34	https://github.com/google/kmsan.git master	3c8ca70889aa	8c88c9c1	.config	log	report
ci-upstream-kmsan-gce	2019/10/19 15:10	https://github.com/google/kmsan.git master	3c8ca70889aa	8c88c9c1	.config	log	report
ci-upstream-kmsan-gce	2019/10/19 11:07	https://github.com/google/kmsan.git master	3c8ca70889aa	8c88c9c1	.config	log	report
ci-upstream-kmsan-gce	2019/10/19 06:22	https://github.com/google/kmsan.git master	3c8ca70889aa	8c88c9c1	.config	log	report
ci-upstream-kmsan-gce	2019/10/18 23:05	https://github.com/google/kmsan.git master	3c8ca70889aa	8c88c9c1	.config	log	report
ci-upstream-kmsan-gce	2019/10/18 21:00	https://github.com/google/kmsan.git master	3c8ca70889aa	8c88c9c1	.config	log	report
ci-upstream-kmsan-gce	2019/10/15 16:30	https://github.com/google/kmsan.git master	c24534505750	b5268b89	.config	log	report
ci-upstream-kmsan-gce	2019/10/14 07:41	https://github.com/google/kmsan.git master	fa1690255288	2f661ec4	.config	log	report
ci-upstream-kmsan-gce	2019/10/14 05:20	https://github.com/google/kmsan.git master	fa1690255288	2f661ec4	.config	log	report
ci-upstream-kmsan-gce	2019/10/11 12:52	https://github.com/google/kmsan.git master	c38191cb7026	1a3bad90	.config	log	report
ci-upstream-kmsan-gce	2019/10/11 07:01	https://github.com/google/kmsan.git master	c38191cb7026	1a3bad90	.config	log	report
ci-upstream-kmsan-gce	2019/10/09 01:28	https://github.com/google/kmsan.git master	cebb918b7474	b1ebbfef	.config	log	report
ci-upstream-kmsan-gce	2019/10/08 17:57	https://github.com/google/kmsan.git master	cebb918b7474	b1ebbfef	.config	log	report
ci-upstream-kmsan-gce	2019/10/08 11:25	https://github.com/google/kmsan.git master	cebb918b7474	28ac6e64	.config	log	report
ci-upstream-kmsan-gce	2019/10/07 03:20	https://github.com/google/kmsan.git master	1e76a3e537c3	f3f7d9c8	.config	log	report
ci-upstream-kmsan-gce	2019/10/06 13:03	https://github.com/google/kmsan.git master	1e76a3e537c3	f3f7d9c8	.config	log	report
ci-upstream-kmsan-gce	2019/10/06 11:59	https://github.com/google/kmsan.git master	1e76a3e537c3	f3f7d9c8	.config	log	report
ci-upstream-kmsan-gce	2019/10/06 09:37	https://github.com/google/kmsan.git master	1e76a3e537c3	f3f7d9c8	.config	log	report
ci-upstream-kmsan-gce	2019/10/06 01:01	https://github.com/google/kmsan.git master	1e76a3e537c3	f3f7d9c8	.config	log	report
ci-upstream-kmsan-gce	2019/10/05 20:46	https://github.com/google/kmsan.git master	1e76a3e537c3	f3f7d9c8	.config	log	report
ci-upstream-kmsan-gce	2019/10/05 12:33	https://github.com/google/kmsan.git master	1e76a3e537c3	f3f7d9c8	.config	log	report
ci-upstream-kmsan-gce	2019/10/04 11:05	https://github.com/google/kmsan.git master	1e76a3e537c3	fc17ba49	.config	log	report
ci-upstream-kmsan-gce	2019/10/02 19:40	https://github.com/google/kmsan.git master	1e76a3e537c3	2e29b534	.config	log	report
ci-upstream-kmsan-gce	2019/10/02 18:04	https://github.com/google/kmsan.git master	1e76a3e537c3	2e29b534	.config	log	report
ci-upstream-kmsan-gce	2019/10/02 17:00	https://github.com/google/kmsan.git master	1e76a3e537c3	2e29b534	.config	log	report
ci-upstream-kmsan-gce	2019/10/02 05:00	https://github.com/google/kmsan.git master	f5f9d3ce4686	b7a87a83	.config	log	report
ci-upstream-kmsan-gce	2019/10/02 03:29	https://github.com/google/kmsan.git master	f5f9d3ce4686	b7a87a83	.config	log	report
ci-upstream-kmsan-gce	2019/10/02 02:55	https://github.com/google/kmsan.git master	f5f9d3ce4686	b7a87a83	.config	log	report
ci-upstream-kmsan-gce	2019/09/30 14:02	https://github.com/google/kmsan.git master	f5f9d3ce4686	c7a4fb99	.config	log	report
ci-upstream-kmsan-gce	2019/09/30 14:01	https://github.com/google/kmsan.git master	f5f9d3ce4686	c7a4fb99	.config	log	report
ci-upstream-kmsan-gce	2019/09/29 13:33	https://github.com/google/kmsan.git master	124037e07586	c1ad5441	.config	log	report
ci-upstream-kmsan-gce	2019/09/29 05:26	https://github.com/google/kmsan.git master	124037e07586	eb6b9855	.config	log	report
ci-upstream-kmsan-gce	2019/09/29 03:40	https://github.com/google/kmsan.git master	124037e07586	eb6b9855	.config	log	report
ci-upstream-kmsan-gce	2019/09/27 08:10	https://github.com/google/kmsan.git master	2eb4eee5708b	2f1548bc	.config	log	report
ci-upstream-kmsan-gce	2019/09/26 04:57	https://github.com/google/kmsan.git master	cebbfdbcf2b7	24d405a3	.config	log	report
ci-upstream-kmsan-gce	2019/09/25 23:15	https://github.com/google/kmsan.git master	cebbfdbcf2b7	a3355dba	.config	log	report
ci-upstream-kmsan-gce	2019/09/06 21:33	https://github.com/google/kmsan.git master	014077b5cd62	a60cb4cd	.config	log	report
ci-upstream-kmsan-gce	2019/06/27 20:09	https://github.com/google/kmsan.git master	41550654dedf	7509bf36	.config	log	report
ci-upstream-kmsan-gce	2019/06/09 22:01	https://github.com/google/kmsan.git master	62c1edc4b8ee	0159583c	.config	log	report
ci-upstream-kmsan-gce	2019/06/05 18:49	https://github.com/google/kmsan.git master	f75e4cfea97f	bfb4a51e	.config	log	report
ci-upstream-kmsan-gce	2019/06/04 07:39	https://github.com/google/kmsan.git master	f75e4cfea97f	ce07a7ae	.config	log	report