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BUG: KCSAN: data-race in _prb_read_valid / prb_reserve

write to 0xffffffff866daa80 of 8 bytes by task 3330 on cpu 1:
 prb_reserve+0x740/0xb60
 vprintk_store+0x53f/0x810 kernel/printk/printk.c:2301
 vprintk_emit+0x15e/0x680 kernel/printk/printk.c:2383
 vprintk_default+0x26/0x30 kernel/printk/printk.c:2422
 vprintk+0x75/0x80 kernel/printk/printk_safe.c:68
 _printk+0x7a/0xa0 kernel/printk/printk.c:2432
 vhci_shutdown_connection+0xc1/0x1e0 drivers/usb/usbip/vhci_hcd.c:1032
 event_handler+0x18b/0x350 drivers/usb/usbip/usbip_event.c:79
 process_one_work kernel/workqueue.c:3229 [inline]
 process_scheduled_works+0x483/0x9a0 kernel/workqueue.c:3310
 worker_thread+0x51d/0x6f0 kernel/workqueue.c:3391
 kthread+0x1d1/0x210 kernel/kthread.c:389
 ret_from_fork+0x4b/0x60 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

read to 0xffffffff866daa80 of 8 bytes by task 21724 on cpu 0:
 desc_read kernel/printk/printk_ringbuffer.c:486 [inline]
 desc_read_finalized_seq kernel/printk/printk_ringbuffer.c:1874 [inline]
 prb_read kernel/printk/printk_ringbuffer.c:1922 [inline]
 _prb_read_valid+0x1ec/0xba0 kernel/printk/printk_ringbuffer.c:2113
 prb_read_valid+0x3d/0x60 kernel/printk/printk_ringbuffer.c:2182
 printk_get_next_message+0xd8/0x6f0 kernel/printk/printk.c:2963
 console_emit_next_record kernel/printk/printk.c:3046 [inline]
 console_flush_all+0x28a/0x770 kernel/printk/printk.c:3180
 __console_flush_and_unlock kernel/printk/printk.c:3239 [inline]
 console_unlock+0xab/0x330 kernel/printk/printk.c:3279
 con_shutdown+0x4b/0x60 drivers/tty/vt/vt.c:3569
 release_tty+0x84/0x4f0 drivers/tty/tty_io.c:1589
 tty_release_struct+0x97/0xb0 drivers/tty/tty_io.c:1701
 tty_release+0x8e4/0x930 drivers/tty/tty_io.c:1861
 __fput+0x17a/0x6d0 fs/file_table.c:431
 ____fput+0x1c/0x30 fs/file_table.c:459
 task_work_run+0x13a/0x1a0 kernel/task_work.c:239
 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
 exit_to_user_mode_loop kernel/entry/common.c:114 [inline]
 exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline]
 __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
 syscall_exit_to_user_mode+0xbe/0x130 kernel/entry/common.c:218
 do_syscall_64+0xd6/0x1c0 arch/x86/entry/common.c:89
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0x0000000000000000 -> 0x0000000000002cd4

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 21724 Comm: syz.8.5797 Tainted: G        W          6.12.0-rc7-syzkaller-00125-gcfaaa7d010d1 #0
Tainted: [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
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