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BUG: KCSAN: data-race in _prb_read_valid / prb_reserve

write to 0xffffffff8690f4b0 of 88 bytes by task 2655 on cpu 0:
 prb_reserve+0x696/0xaf0 kernel/printk/printk_ringbuffer.c:1635
 vprintk_store+0x56d/0x860 kernel/printk/printk.c:2326
 vprintk_emit+0x178/0x650 kernel/printk/printk.c:2426
 dev_vprintk_emit+0x242/0x2a0 drivers/base/core.c:4917
 dev_printk_emit+0x84/0xb0 drivers/base/core.c:4928
 __dev_printk+0xf3/0x110 drivers/base/core.c:4940
 _dev_info+0x9b/0xd0 drivers/base/core.c:4986
 hub_configure drivers/usb/core/hub.c:1526 [inline]
 hub_probe+0xcc7/0x1700 drivers/usb/core/hub.c:2005
 usb_probe_interface+0x43b/0x680 drivers/usb/core/driver.c:396
 call_driver_probe drivers/base/dd.c:-1 [inline]
 really_probe+0x1bc/0x5a0 drivers/base/dd.c:657
 __driver_probe_device+0x121/0x190 drivers/base/dd.c:799
 driver_probe_device+0x37/0x2f0 drivers/base/dd.c:829
 __device_attach_driver+0x205/0x310 drivers/base/dd.c:957
 bus_for_each_drv+0x1c0/0x230 drivers/base/bus.c:462
 __device_attach+0x1c7/0x290 drivers/base/dd.c:1029
 device_attach+0x17/0x20 drivers/base/dd.c:1072
 proc_ioctl+0x2f7/0x400 drivers/usb/core/devio.c:2368
 proc_ioctl_default+0x71/0xa0 drivers/usb/core/devio.c:2403
 usbdev_do_ioctl drivers/usb/core/devio.c:2767 [inline]
 usbdev_ioctl+0xe97/0x1710 drivers/usb/core/devio.c:2827
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:907 [inline]
 __se_sys_ioctl+0xce/0x140 fs/ioctl.c:893
 __x64_sys_ioctl+0x43/0x50 fs/ioctl.c:893
 x64_sys_call+0x19a8/0x2fb0 arch/x86/include/generated/asm/syscalls_64.h:17
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xd2/0x200 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffffffff8690f4b0 of 8 bytes by task 2984 on cpu 1:
 desc_read kernel/printk/printk_ringbuffer.c:486 [inline]
 prb_first_seq kernel/printk/printk_ringbuffer.c:1957 [inline]
 _prb_read_valid+0x383/0x920 kernel/printk/printk_ringbuffer.c:2114
 prb_read_valid+0x3c/0x60 kernel/printk/printk_ringbuffer.c:2185
 syslog_print+0x23a/0x540 kernel/printk/printk.c:1650
 do_syslog+0x52b/0x7e0 kernel/printk/printk.c:1785
 __do_sys_syslog kernel/printk/printk.c:1877 [inline]
 __se_sys_syslog kernel/printk/printk.c:1875 [inline]
 __x64_sys_syslog+0x41/0x50 kernel/printk/printk.c:1875
 x64_sys_call+0x2ea0/0x2fb0 arch/x86/include/generated/asm/syscalls_64.h:104
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xd2/0x200 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0x0000000000003576 -> 0x0000000000005576

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 2984 Comm: klogd Tainted: G        W           6.16.0-rc7-syzkaller-00140-gec2df4364666 #0 PREEMPT(voluntary) 
Tainted: [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
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