KMSAN: uninit-value in smsc75xx_bind

[yshigeru]

https://syzkaller.appspot.com/bug?extid=6966546b78d050bb0b5d

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BUG: KMSAN: uninit-value in smsc75xx_wait_ready drivers/net/usb/smsc75xx.c:976 [inline]
BUG: KMSAN: uninit-value in smsc75xx_bind+0x57c/0x13c0 drivers/net/usb/smsc75xx.c:1483
CPU: 0 PID: 1980 Comm: kworker/0:2 Not tainted 5.11.0-rc7-syzkaller #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:79 [inline]
 dump_stack+0x21c/0x280 lib/dump_stack.c:120
 kmsan_report+0xfb/0x1e0 mm/kmsan/kmsan_report.c:118
 __msan_warning+0x5f/0xa0 mm/kmsan/kmsan_instr.c:197
 smsc75xx_wait_ready drivers/net/usb/smsc75xx.c:976 [inline]
 smsc75xx_bind+0x57c/0x13c0 drivers/net/usb/smsc75xx.c:1483
 usbnet_probe+0x115e/0x3e80 drivers/net/usb/usbnet.c:1703
 usb_probe_interface+0xfcc/0x1520 drivers/usb/core/driver.c:396
 really_probe+0xe15/0x24d0 drivers/base/dd.c:558
 driver_probe_device+0x29d/0x3a0 drivers/base/dd.c:740
 __device_attach_driver+0x63f/0x830 drivers/base/dd.c:846
 bus_for_each_drv+0x2c8/0x3f0 drivers/base/bus.c:431
 __device_attach+0x56a/0x890 drivers/base/dd.c:914
 device_initial_probe+0x4a/0x60 drivers/base/dd.c:961
 bus_probe_device+0x17e/0x3d0 drivers/base/bus.c:491
 device_add+0x2c15/0x31d0 drivers/base/core.c:3109
 usb_set_configuration+0x3872/0x3eb0 drivers/usb/core/message.c:2164
 usb_generic_driver_probe+0x138/0x300 drivers/usb/core/generic.c:238
 usb_probe_device+0x317/0x570 drivers/usb/core/driver.c:293
 really_probe+0xe15/0x24d0 drivers/base/dd.c:558
 driver_probe_device+0x29d/0x3a0 drivers/base/dd.c:740
 __device_attach_driver+0x63f/0x830 drivers/base/dd.c:846
 bus_for_each_drv+0x2c8/0x3f0 drivers/base/bus.c:431
 __device_attach+0x56a/0x890 drivers/base/dd.c:914
 device_initial_probe+0x4a/0x60 drivers/base/dd.c:961
 bus_probe_device+0x17e/0x3d0 drivers/base/bus.c:491
 device_add+0x2c15/0x31d0 drivers/base/core.c:3109
 usb_new_device+0x1bd4/0x2a30 drivers/usb/core/hub.c:2555
 hub_port_connect drivers/usb/core/hub.c:5223 [inline]
 hub_port_connect_change drivers/usb/core/hub.c:5363 [inline]
 port_event drivers/usb/core/hub.c:5509 [inline]
 hub_event+0x5b99/0x8870 drivers/usb/core/hub.c:5591
 process_one_work+0x1219/0x1fe0 kernel/workqueue.c:2275
 worker_thread+0x10ec/0x2340 kernel/workqueue.c:2421
 kthread+0x521/0x560 kernel/kthread.c:292
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:296

Local variable ----buf.i91@smsc75xx_bind created at:
 __smsc75xx_read_reg drivers/net/usb/smsc75xx.c:83 [inline]
 smsc75xx_wait_ready drivers/net/usb/smsc75xx.c:969 [inline]
 smsc75xx_bind+0x435/0x13c0 drivers/net/usb/smsc75xx.c:1483
 __smsc75xx_read_reg drivers/net/usb/smsc75xx.c:83 [inline]
 smsc75xx_wait_ready drivers/net/usb/smsc75xx.c:969 [inline]
 smsc75xx_bind+0x435/0x13c0 drivers/net/usb/smsc75xx.c:1483

[yshigeru]

類似事象：https://github.com/yshigeru/linux-devel/commit/920a9fa27e7805499cfe78491b36fed2322c02ec

[yshigeru]

Sent the patch: https://lore.kernel.org/all/20230923173549.3284502-1-syoshida@redhat.com/