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: 110d, last: 15d

Sample crash report:

ax88179_178a 1-1:0.186 (unnamed net_device) (uninitialized): Failed to write reg index 0x000d: -71
ax88179_178a 1-1:0.186 (unnamed net_device) (uninitialized): Failed to write reg index 0x000e: -71
ax88179_178a 1-1:0.186 (unnamed net_device) (uninitialized): Failed to write reg index 0x000d: -71
ax88179_178a 1-1:0.186 (unnamed net_device) (uninitialized): Failed to write reg index 0x000e: -71
ax88179_178a 1-1:0.186 (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: 1 PID: 3353 Comm: kworker/1:2 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
 mii_nway_restart+0x141/0x260 drivers/net/mii.c:467
 ax88179_bind+0xee3/0x1a10 drivers/net/usb/ax88179_178a.c:1329
 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
 worker_thread+0x111b/0x2460 kernel/workqueue.c:2415
 kthread+0x4b5/0x4f0 kernel/kthread.c:254
 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 drivers/net/usb/ax88179_178a.c:199 [inline]
 ax88179_read_cmd drivers/net/usb/ax88179_178a.c:311 [inline]
 ax88179_mdio_read+0x7b/0x240 drivers/net/usb/ax88179_178a.c:369
 mii_nway_restart+0xcf/0x260 drivers/net/mii.c:465
==================================================================

All crashes (31):
Manager	Time	Kernel	Commit	Syzkaller	Config	Log	Report	Syz repro	C repro	Maintainers
ci-upstream-kmsan-gce	2019/06/04 08:56	https://github.com/google/kmsan.git master	f75e4cfe	ce07a7ae	.config	log	report	syz	C	davem@davemloft.net, linux-kernel@vger.kernel.org, netdev@vger.kernel.org
ci-upstream-kmsan-gce	2019/08/12 00:31	https://github.com/google/kmsan.git master	61ccdad1	acb51638	.config	log	report	syz	C	davem@davemloft.net, linux-kernel@vger.kernel.org, netdev@vger.kernel.org
ci-upstream-kmsan-gce	2019/08/11 10:37	https://github.com/google/kmsan.git master	61ccdad1	acb51638	.config	log	report	syz	C	davem@davemloft.net, linux-kernel@vger.kernel.org, netdev@vger.kernel.org
ci-upstream-kmsan-gce	2019/08/09 17:23	https://github.com/google/kmsan.git master	61ccdad1	ede31a9b	.config	log	report	syz	C	davem@davemloft.net, linux-kernel@vger.kernel.org, netdev@vger.kernel.org
ci-upstream-kmsan-gce	2019/07/28 02:28	https://github.com/google/kmsan.git master	beaab8a3	c85e1c5b	.config	log	report	syz	C	davem@davemloft.net, linux-kernel@vger.kernel.org, netdev@vger.kernel.org
ci-upstream-kmsan-gce	2019/07/02 09:57	https://github.com/google/kmsan.git master	41550654	cccc4302	.config	log	report	syz	C	davem@davemloft.net, linux-kernel@vger.kernel.org, netdev@vger.kernel.org
ci-upstream-kmsan-gce	2019/06/04 07:39	https://github.com/google/kmsan.git master	f75e4cfe	ce07a7ae	.config	log	report			davem@davemloft.net, linux-kernel@vger.kernel.org, netdev@vger.kernel.org
ci-upstream-kmsan-gce	2019/09/06 21:33	https://github.com/google/kmsan.git master	014077b5	a60cb4cd	.config	log	report			davem@davemloft.net, linux-kernel@vger.kernel.org, netdev@vger.kernel.org
ci-upstream-kmsan-gce	2019/09/02 13:25	https://github.com/google/kmsan.git master	e88bfb81	db7c31ca	.config	log	report			davem@davemloft.net, linux-kernel@vger.kernel.org, netdev@vger.kernel.org
ci-upstream-kmsan-gce	2019/09/02 13:24	https://github.com/google/kmsan.git master	e88bfb81	db7c31ca	.config	log	report			davem@davemloft.net, linux-kernel@vger.kernel.org, netdev@vger.kernel.org
ci-upstream-kmsan-gce	2019/08/31 04:03	https://github.com/google/kmsan.git master	77d232b6	fd37b39e	.config	log	report			davem@davemloft.net, linux-kernel@vger.kernel.org, netdev@vger.kernel.org
ci-upstream-kmsan-gce	2019/08/16 05:08	https://github.com/google/kmsan.git master	61ccdad1	8fd428a1	.config	log	report			davem@davemloft.net, linux-kernel@vger.kernel.org, netdev@vger.kernel.org
ci-upstream-kmsan-gce	2019/08/07 22:12	https://github.com/google/kmsan.git master	61ccdad1	e6ebef88	.config	log	report			davem@davemloft.net, linux-kernel@vger.kernel.org, netdev@vger.kernel.org
ci-upstream-kmsan-gce	2019/08/07 04:39	https://github.com/google/kmsan.git master	ae0c578a	c6f01e54	.config	log	report			davem@davemloft.net, linux-kernel@vger.kernel.org, netdev@vger.kernel.org
ci-upstream-kmsan-gce	2019/08/07 02:12	https://github.com/google/kmsan.git master	ae0c578a	c6f01e54	.config	log	report			davem@davemloft.net, linux-kernel@vger.kernel.org, netdev@vger.kernel.org
ci-upstream-kmsan-gce	2019/08/07 02:09	https://github.com/google/kmsan.git master	ae0c578a	c6f01e54	.config	log	report			davem@davemloft.net, linux-kernel@vger.kernel.org, netdev@vger.kernel.org
ci-upstream-kmsan-gce	2019/08/07 00:42	https://github.com/google/kmsan.git master	ae0c578a	c6f01e54	.config	log	report			davem@davemloft.net, linux-kernel@vger.kernel.org, netdev@vger.kernel.org
ci-upstream-kmsan-gce	2019/08/07 00:19	https://github.com/google/kmsan.git master	ae0c578a	c6f01e54	.config	log	report			davem@davemloft.net, linux-kernel@vger.kernel.org, netdev@vger.kernel.org
ci-upstream-kmsan-gce	2019/08/06 18:47	https://github.com/google/kmsan.git master	ae0c578a	c6f01e54	.config	log	report			davem@davemloft.net, linux-kernel@vger.kernel.org, netdev@vger.kernel.org
ci-upstream-kmsan-gce	2019/08/01 03:49	https://github.com/google/kmsan.git master	beaab8a3	c692b5bd	.config	log	report			davem@davemloft.net, linux-kernel@vger.kernel.org, netdev@vger.kernel.org
ci-upstream-kmsan-gce	2019/08/01 01:59	https://github.com/google/kmsan.git master	beaab8a3	c692b5bd	.config	log	report			davem@davemloft.net, linux-kernel@vger.kernel.org, netdev@vger.kernel.org
ci-upstream-kmsan-gce	2019/07/23 13:35	https://github.com/google/kmsan.git master	beaab8a3	de453f34	.config	log	report			davem@davemloft.net, linux-kernel@vger.kernel.org, netdev@vger.kernel.org
ci-upstream-kmsan-gce	2019/07/23 13:27	https://github.com/google/kmsan.git master	beaab8a3	de453f34	.config	log	report			davem@davemloft.net, linux-kernel@vger.kernel.org, netdev@vger.kernel.org
ci-upstream-kmsan-gce	2019/07/22 04:13	https://github.com/google/kmsan.git master	beaab8a3	1656845f	.config	log	report
ci-upstream-kmsan-gce	2019/07/10 14:22	https://github.com/google/kmsan.git master	4009f3cf	f62e1e85	.config	log	report			davem@davemloft.net, linux-kernel@vger.kernel.org, netdev@vger.kernel.org
ci-upstream-kmsan-gce	2019/07/01 00:34	https://github.com/google/kmsan.git master	41550654	699d6448	.config	log	report			davem@davemloft.net, linux-kernel@vger.kernel.org, netdev@vger.kernel.org
ci-upstream-kmsan-gce	2019/06/28 02:10	https://github.com/google/kmsan.git master	41550654	7509bf36	.config	log	report			davem@davemloft.net, linux-kernel@vger.kernel.org, netdev@vger.kernel.org
ci-upstream-kmsan-gce	2019/06/27 20:09	https://github.com/google/kmsan.git master	41550654	7509bf36	.config	log	report			davem@davemloft.net, linux-kernel@vger.kernel.org, netdev@vger.kernel.org
ci-upstream-kmsan-gce	2019/06/27 20:09	https://github.com/google/kmsan.git master	41550654	7509bf36	.config	log	report			davem@davemloft.net, linux-kernel@vger.kernel.org, netdev@vger.kernel.org
ci-upstream-kmsan-gce	2019/06/09 22:01	https://github.com/google/kmsan.git master	62c1edc4	0159583c	.config	log	report			davem@davemloft.net, linux-kernel@vger.kernel.org, netdev@vger.kernel.org
ci-upstream-kmsan-gce	2019/06/05 18:49	https://github.com/google/kmsan.git master	f75e4cfe	bfb4a51e	.config	log	report			davem@davemloft.net, linux-kernel@vger.kernel.org, netdev@vger.kernel.org