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BUG: KCSAN: data-race in data_alloc / data_push_tail

write to 0xffffffff88f1ebd0 of 8 bytes by task 9680 on cpu 1:
 data_alloc+0x205/0x2b0 kernel/printk/printk_ringbuffer.c:1071
 prb_reserve+0x8f0/0xbc0 kernel/printk/printk_ringbuffer.c:1549
 vprintk_store+0x3e9/0x9c0 kernel/printk/printk.c:2029
 vprintk_emit+0xca/0x3e0 kernel/printk/printk.c:2081
 dev_vprintk_emit+0x1c6/0x1ea drivers/base/core.c:4434
 dev_printk_emit+0x6a/0x8c drivers/base/core.c:4445
 __dev_printk+0xfa/0x103 drivers/base/core.c:4457
 _dev_info+0x76/0x96 drivers/base/core.c:4503
 hub_port_init+0x7d3/0x18d0 drivers/usb/core/hub.c:4647
 hub_port_connect drivers/usb/core/hub.c:5155 [inline]
 hub_port_connect_change drivers/usb/core/hub.c:5363 [inline]
 port_event drivers/usb/core/hub.c:5509 [inline]
 hub_event+0x1a1e/0x2b60 drivers/usb/core/hub.c:5591
 process_one_work+0x3e1/0x950 kernel/workqueue.c:2275
 worker_thread+0x616/0xa70 kernel/workqueue.c:2421
 kthread+0x20b/0x230 kernel/kthread.c:292
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294

read to 0xffffffff88f1ebd0 of 8 bytes by task 9713 on cpu 0:
 data_make_reusable kernel/printk/printk_ringbuffer.c:587 [inline]
 data_push_tail+0x125/0x460 kernel/printk/printk_ringbuffer.c:672
 data_alloc+0xbc/0x2b0 kernel/printk/printk_ringbuffer.c:1043
 prb_reserve+0x8f0/0xbc0 kernel/printk/printk_ringbuffer.c:1549
 vprintk_store+0x3e9/0x9c0 kernel/printk/printk.c:2029
 vprintk_emit+0xca/0x3e0 kernel/printk/printk.c:2081
 vprintk_default+0x22/0x30 kernel/printk/printk.c:2115
 vprintk_func+0x11b/0x120 kernel/printk/printk_safe.c:401
 printk+0x62/0x82 kernel/printk/printk.c:2146
 really_probe+0xb2a/0xba0 drivers/base/dd.c:645
 driver_probe_device+0xcc/0x120 drivers/base/dd.c:740
 __device_attach_driver+0x255/0x290 drivers/base/dd.c:846
 bus_for_each_drv+0xd8/0x140 drivers/base/bus.c:431
 __device_attach+0x1a0/0x290 drivers/base/dd.c:914
 device_initial_probe+0x16/0x20 drivers/base/dd.c:961
 bus_probe_device+0x7a/0x140 drivers/base/bus.c:491
 device_add+0xcb2/0xe50 drivers/base/core.c:3242
 usb_set_configuration+0x108d/0x1370 drivers/usb/core/message.c:2164
 usb_generic_driver_probe+0x54/0xd0 drivers/usb/core/generic.c:238
 usb_probe_device+0xfb/0x1a0 drivers/usb/core/driver.c:293
 really_probe+0x4ee/0xba0 drivers/base/dd.c:558
 driver_probe_device+0xcc/0x120 drivers/base/dd.c:740
 __device_attach_driver+0x255/0x290 drivers/base/dd.c:846
 bus_for_each_drv+0xd8/0x140 drivers/base/bus.c:431
 __device_attach+0x1a0/0x290 drivers/base/dd.c:914
 device_initial_probe+0x16/0x20 drivers/base/dd.c:961
 bus_probe_device+0x7a/0x140 drivers/base/bus.c:491
 device_add+0xcb2/0xe50 drivers/base/core.c:3242
 usb_new_device+0x89f/0xc60 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+0x1d17/0x2b60 drivers/usb/core/hub.c:5591
 process_one_work+0x3e1/0x950 kernel/workqueue.c:2275
 worker_thread+0x616/0xa70 kernel/workqueue.c:2421
 kthread+0x20b/0x230 kernel/kthread.c:292
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 9713 Comm: kworker/0:7 Not tainted 5.12.0-rc3-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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