KMSAN: uninit-value in smsc95xx_reset

[yshigeru]

https://syzkaller.appspot.com/bug?extid=c74c24b43c9ae534f0e0

smsc95xx 1-1:0.0 (unnamed net_device) (uninitialized): Failed to read reg index 0x00000030: -32
smsc95xx 1-1:0.0 (unnamed net_device) (uninitialized): Error reading E2P_CMD
=====================================================
BUG: KMSAN: uninit-value in smsc95xx_reset+0x409/0x25f0 drivers/net/usb/smsc95xx.c:896
 smsc95xx_reset+0x409/0x25f0 drivers/net/usb/smsc95xx.c:896
 smsc95xx_bind+0x9bc/0x22e0 drivers/net/usb/smsc95xx.c:1131
 usbnet_probe+0x100b/0x4060 drivers/net/usb/usbnet.c:1750
 usb_probe_interface+0xc75/0x1210 drivers/usb/core/driver.c:396
 really_probe+0x506/0xf40 drivers/base/dd.c:658
 __driver_probe_device+0x2a7/0x5d0 drivers/base/dd.c:800
 driver_probe_device+0x72/0x7b0 drivers/base/dd.c:830
 __device_attach_driver+0x55a/0x8f0 drivers/base/dd.c:958
 bus_for_each_drv+0x3ff/0x620 drivers/base/bus.c:457
 __device_attach+0x3bd/0x640 drivers/base/dd.c:1030
 device_initial_probe+0x32/0x40 drivers/base/dd.c:1079
 bus_probe_device+0x3d8/0x5a0 drivers/base/bus.c:532
 device_add+0x16ae/0x1f20 drivers/base/core.c:3622
 usb_set_configuration+0x31c9/0x38c0 drivers/usb/core/message.c:2207
 usb_generic_driver_probe+0x109/0x2a0 drivers/usb/core/generic.c:238
 usb_probe_device+0x290/0x4a0 drivers/usb/core/driver.c:293
 really_probe+0x506/0xf40 drivers/base/dd.c:658
 __driver_probe_device+0x2a7/0x5d0 drivers/base/dd.c:800
 driver_probe_device+0x72/0x7b0 drivers/base/dd.c:830
 __device_attach_driver+0x55a/0x8f0 drivers/base/dd.c:958
 bus_for_each_drv+0x3ff/0x620 drivers/base/bus.c:457
 __device_attach+0x3bd/0x640 drivers/base/dd.c:1030
 device_initial_probe+0x32/0x40 drivers/base/dd.c:1079
 bus_probe_device+0x3d8/0x5a0 drivers/base/bus.c:532
 device_add+0x16ae/0x1f20 drivers/base/core.c:3622
 usb_new_device+0x15f6/0x22f0 drivers/usb/core/hub.c:2589
 hub_port_connect drivers/usb/core/hub.c:5440 [inline]
 hub_port_connect_change drivers/usb/core/hub.c:5580 [inline]
 port_event drivers/usb/core/hub.c:5740 [inline]
 hub_event+0x53bc/0x7290 drivers/usb/core/hub.c:5822
 process_one_work kernel/workqueue.c:2630 [inline]
 process_scheduled_works+0x104e/0x1e70 kernel/workqueue.c:2703
 worker_thread+0xf45/0x1490 kernel/workqueue.c:2784
 kthread+0x3e8/0x540 kernel/kthread.c:388
 ret_from_fork+0x66/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:304

Local variable buf.i225 created at:
 smsc95xx_read_reg drivers/net/usb/smsc95xx.c:90 [inline]
 smsc95xx_reset+0x203/0x25f0 drivers/net/usb/smsc95xx.c:892
 smsc95xx_bind+0x9bc/0x22e0 drivers/net/usb/smsc95xx.c:1131

CPU: 1 PID: 773 Comm: kworker/1:2 Not tainted 6.6.0-rc1-syzkaller-00125-ge42bebf6db29 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/04/2023
Workqueue: usb_hub_wq hub_event
=====================================================

[yshigeru]

Sent v1 patch: https://lore.kernel.org/all/20231020170344.2450248-1-syoshida@redhat.com/

[yshigeru]

Merged: https://git.kernel.org/pub/scm/linux/kernel/git/netdev/net.git/commit/?id=51a32e828109