==================================================================
BUG: KCSAN: data-race in _prb_read_valid / prb_reserve

write to 0xffffffff868b82c0 of 88 bytes by task 19642 on cpu 1:
 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+0x1bf/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:598 [inline]
 __se_sys_ioctl+0xcb/0x140 fs/ioctl.c:584
 __x64_sys_ioctl+0x43/0x50 fs/ioctl.c:584
 x64_sys_call+0x1816/0x2ff0 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 0xffffffff868b82c0 of 8 bytes by task 19644 on cpu 0:
 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_first_valid_seq+0x35/0x70 kernel/printk/printk_ringbuffer.c:2241
 devkmsg_open+0x17d/0x1c0 kernel/printk/printk.c:967
 memory_open+0xca/0xf0 drivers/char/mem.c:711
 chrdev_open+0x2eb/0x3a0 fs/char_dev.c:414
 do_dentry_open+0x646/0xa20 fs/open.c:965
 vfs_open+0x37/0x1e0 fs/open.c:1095
 do_open fs/namei.c:3887 [inline]
 path_openat+0x1c5e/0x2170 fs/namei.c:4046
 do_filp_open+0x109/0x230 fs/namei.c:4073
 do_sys_openat2+0xa6/0x110 fs/open.c:1435
 do_sys_open fs/open.c:1450 [inline]
 __do_sys_openat fs/open.c:1466 [inline]
 __se_sys_openat fs/open.c:1461 [inline]
 __x64_sys_openat+0xf2/0x120 fs/open.c:1461
 x64_sys_call+0x2e9c/0x2ff0 arch/x86/include/generated/asm/syscalls_64.h:258
 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: 0x00000000000025ca -> 0x00000000000045ca

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 19644 Comm: fido_id Tainted: G        W           6.16.0-syzkaller-01056-gae388edd4a8f #0 PREEMPT(voluntary) 
Tainted: [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
==================================================================
fido_id[19644]: Failed to open report descriptor at '/sys/devices/virtual/misc/uhid/report_descriptor': No such file or directory