Subject: [syzbot] KMSAN: uninit-value in ax88179_led_setting

From: syzbot <[email-masked]>
Date: Tue, 15 Feb 2022 02:42:17 -0800

Hello,

syzbot found the following issue on:

HEAD commit:    85cfd6e539bd kmsan: core: delete kmsan_gup_pgd_range()
git tree:       https://github.com/google/kmsan.git master
console output: https://syzkaller.appspot.com/x/log.txt?x=12d6c53c700000
kernel config:  https://syzkaller.appspot.com/x/.config?x=b9807dd5b044fd7a
dashboard link: https://syzkaller.appspot.com/bug?extid=d3dbdf31fbe9d8f5f311
compiler:       clang version 14.0.0 (/usr/local/google/src/llvm-git-monorepo 2b554920f11c8b763cd9ed9003f4e19b919b8e1f), GNU ld (GNU Binutils for Debian) 2.35.2

Unfortunately, I don't have any reproducer for this issue yet.

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: [email-masked]

ax88179_178a 2-1:0.35 (unnamed net_device) (uninitialized): Failed to read reg index 0x0001: -71
ax88179_178a 2-1:0.35 (unnamed net_device) (uninitialized): Failed to read reg index 0x0002: -71
=====================================================
BUG: KMSAN: uninit-value in ax88179_check_eeprom drivers/net/usb/ax88179_178a.c:1074 [inline]
BUG: KMSAN: uninit-value in ax88179_led_setting+0x884/0x30b0 drivers/net/usb/ax88179_178a.c:1168
 ax88179_check_eeprom drivers/net/usb/ax88179_178a.c:1074 [inline]
 ax88179_led_setting+0x884/0x30b0 drivers/net/usb/ax88179_178a.c:1168
 ax88179_bind+0xe75/0x1990 drivers/net/usb/ax88179_178a.c:1411
 usbnet_probe+0x1284/0x4140 drivers/net/usb/usbnet.c:1747
 usb_probe_interface+0xf19/0x1600 drivers/usb/core/driver.c:396
 really_probe+0x67d/0x1510 drivers/base/dd.c:596
 __driver_probe_device+0x3e9/0x530 drivers/base/dd.c:751
 driver_probe_device drivers/base/dd.c:781 [inline]
 __device_attach_driver+0x79f/0x1120 drivers/base/dd.c:898
 bus_for_each_drv+0x2d6/0x3f0 drivers/base/bus.c:427
 __device_attach+0x593/0x8e0 drivers/base/dd.c:969
 device_initial_probe+0x4a/0x60 drivers/base/dd.c:1016
 bus_probe_device+0x17b/0x3e0 drivers/base/bus.c:487
 device_add+0x1d3e/0x2400 drivers/base/core.c:3394
 usb_set_configuration+0x37e9/0x3ed0 drivers/usb/core/message.c:2170
 usb_generic_driver_probe+0x13c/0x300 drivers/usb/core/generic.c:238
 usb_probe_device+0x309/0x570 drivers/usb/core/driver.c:293
 really_probe+0x67d/0x1510 drivers/base/dd.c:596
 __driver_probe_device+0x3e9/0x530 drivers/base/dd.c:751
 driver_probe_device drivers/base/dd.c:781 [inline]
 __device_attach_driver+0x79f/0x1120 drivers/base/dd.c:898
 bus_for_each_drv+0x2d6/0x3f0 drivers/base/bus.c:427
 __device_attach+0x593/0x8e0 drivers/base/dd.c:969
 device_initial_probe+0x4a/0x60 drivers/base/dd.c:1016
 bus_probe_device+0x17b/0x3e0 drivers/base/bus.c:487
 device_add+0x1d3e/0x2400 drivers/base/core.c:3394
 usb_new_device+0x1b8e/0x2950 drivers/usb/core/hub.c:2563
 hub_port_connect drivers/usb/core/hub.c:5353 [inline]
 hub_port_connect_change drivers/usb/core/hub.c:5497 [inline]
 port_event drivers/usb/core/hub.c:5643 [inline]
 hub_event+0x5ad2/0x8910 drivers/usb/core/hub.c:5725
 process_one_work+0xdb9/0x1820 kernel/workqueue.c:2298
 process_scheduled_works kernel/workqueue.c:2361 [inline]
 worker_thread+0x1735/0x21f0 kernel/workqueue.c:2447
 kthread+0x721/0x850 kernel/kthread.c:327
 ret_from_fork+0x1f/0x30

Local variable eeprom.i created at:
 ax88179_check_eeprom drivers/net/usb/ax88179_178a.c:1045 [inline]
 ax88179_led_setting+0x2e2/0x30b0 drivers/net/usb/ax88179_178a.c:1168
 ax88179_bind+0xe75/0x1990 drivers/net/usb/ax88179_178a.c:1411

CPU: 1 PID: 13457 Comm: kworker/1:0 Not tainted 5.16.0-rc5-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: usb_hub_wq hub_event
=====================================================

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