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BUG: KMSAN: uninit-value in number+0x54f/0x2540 lib/vsprintf.c:442
CPU: 0 PID: 8408 Comm: kworker/0:1 Not tainted 5.10.0-rc4-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:77 [inline]
 dump_stack+0x21c/0x280 lib/dump_stack.c:118
 kmsan_report+0xfb/0x1e0 mm/kmsan/kmsan_report.c:118
 __msan_warning+0x5f/0xa0 mm/kmsan/kmsan_instr.c:197
 number+0x54f/0x2540 lib/vsprintf.c:442
 vsnprintf+0x1cd6/0x3600 lib/vsprintf.c:2684
 vscnprintf+0xbe/0x1c0 lib/vsprintf.c:2721
 vprintk_store+0xff/0x1490 kernel/printk/printk.c:1954
 vprintk_emit+0x2ae/0x820 kernel/printk/printk.c:2018
 vprintk_default+0x86/0xa0 kernel/printk/printk.c:2052
 vprintk_func+0x2ed/0x2f0 kernel/printk/printk_safe.c:393
 printk+0x180/0x1cd kernel/printk/printk.c:2083
 sq905_read_data+0x630/0x650 drivers/media/usb/gspca/sq905.c:184
 sd_init+0x184/0x530 drivers/media/usb/gspca/sq905.c:329
 gspca_dev_probe2+0xfab/0x23b0 drivers/media/usb/gspca/gspca.c:1532
 gspca_dev_probe+0x3db/0x440 drivers/media/usb/gspca/gspca.c:1605
 sd_probe+0x8d/0xa0 drivers/media/usb/gspca/gl860/gl860.c:511
 usb_probe_interface+0xfcc/0x1520 drivers/usb/core/driver.c:396
 really_probe+0xebd/0x2420 drivers/base/dd.c:558
 driver_probe_device+0x29d/0x3a0 drivers/base/dd.c:738
 __device_attach_driver+0x63f/0x830 drivers/base/dd.c:844
 bus_for_each_drv+0x2c8/0x3f0 drivers/base/bus.c:431
 __device_attach+0x56a/0x890 drivers/base/dd.c:912
 device_initial_probe+0x4a/0x60 drivers/base/dd.c:959
 bus_probe_device+0x17e/0x3d0 drivers/base/bus.c:491
 device_add+0x397e/0x3f00 drivers/base/core.c:2936
 usb_set_configuration+0x39a2/0x4000 drivers/usb/core/message.c:2159
 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+0xebd/0x2420 drivers/base/dd.c:558
 driver_probe_device+0x29d/0x3a0 drivers/base/dd.c:738
 __device_attach_driver+0x63f/0x830 drivers/base/dd.c:844
 bus_for_each_drv+0x2c8/0x3f0 drivers/base/bus.c:431
 __device_attach+0x56a/0x890 drivers/base/dd.c:912
 device_initial_probe+0x4a/0x60 drivers/base/dd.c:959
 bus_probe_device+0x17e/0x3d0 drivers/base/bus.c:491
 device_add+0x397e/0x3f00 drivers/base/core.c:2936
 usb_new_device+0x1bd4/0x2a30 drivers/usb/core/hub.c:2554
 hub_port_connect drivers/usb/core/hub.c:5222 [inline]
 hub_port_connect_change drivers/usb/core/hub.c:5362 [inline]
 port_event drivers/usb/core/hub.c:5508 [inline]
 hub_event+0x5b99/0x8870 drivers/usb/core/hub.c:5590
 process_one_work+0x1219/0x1fe0 kernel/workqueue.c:2272
 worker_thread+0x123c/0x2730 kernel/workqueue.c:2418
 kthread+0x51c/0x560 kernel/kthread.c:292
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:296

Local variable ----act_len@sq905_read_data created at:
 sq905_read_data+0x87/0x650 drivers/media/usb/gspca/sq905.c:163
 sq905_read_data+0x87/0x650 drivers/media/usb/gspca/sq905.c:163
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