vhci_hcd vhci_hcd.0: pdev(8) rhport(0) sockfd(10)
vhci_hcd vhci_hcd.0: devid(0) speed(1) speed_str(low-speed)
==================================================================
BUG: KCSAN: data-race in data_alloc / prb_reserve

write to 0xffffffff86888df8 of 8 bytes by task 23419 on cpu 1:
 data_alloc+0x27d/0x2b0 kernel/printk/printk_ringbuffer.c:1096
 prb_reserve+0x808/0xaf0 kernel/printk/printk_ringbuffer.c:1669
 vprintk_store+0x56d/0x860 kernel/printk/printk.c:2326
 vprintk_emit+0x178/0x650 kernel/printk/printk.c:2426
 vprintk_default+0x26/0x30 kernel/printk/printk.c:2465
 vprintk+0x1d/0x30 kernel/printk/printk_safe.c:82
 _printk+0x79/0xa0 kernel/printk/printk.c:2475
 vhci_rx_pdu drivers/usb/usbip/vhci_rx.c:224 [inline]
 vhci_rx_loop+0x4a5/0x5f0 drivers/usb/usbip/vhci_rx.c:265
 kthread+0x489/0x510 kernel/kthread.c:464
 ret_from_fork+0xda/0x150 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

read to 0xffffffff86888df8 of 8 bytes by task 23418 on cpu 0:
 desc_read kernel/printk/printk_ringbuffer.c:482 [inline]
 desc_push_tail kernel/printk/printk_ringbuffer.c:778 [inline]
 desc_reserve kernel/printk/printk_ringbuffer.c:924 [inline]
 prb_reserve+0x221/0xaf0 kernel/printk/printk_ringbuffer.c:1619
 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
 attach_store+0x5f8/0x680 drivers/usb/usbip/vhci_sysfs.c:439
 dev_attr_store+0x47/0x70 drivers/base/core.c:2440
 sysfs_kf_write+0xfe/0x120 fs/sysfs/file.c:145
 kernfs_fop_write_iter+0x1c1/0x2d0 fs/kernfs/file.c:334
 new_sync_write fs/read_write.c:593 [inline]
 vfs_write+0x4a0/0x8e0 fs/read_write.c:686
 ksys_write+0xda/0x1a0 fs/read_write.c:738
 __do_sys_write fs/read_write.c:749 [inline]
 __se_sys_write fs/read_write.c:746 [inline]
 __x64_sys_write+0x40/0x50 fs/read_write.c:746
 x64_sys_call+0x2cdd/0x2fb0 arch/x86/include/generated/asm/syscalls_64.h:2
 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: 0x00000000000c5e48 -> 0x00000000001576a0

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 23418 Comm: syz.8.6640 Tainted: G        W           6.16.0-rc5-syzkaller-00193-g40f92e79b0aa #0 PREEMPT(voluntary) 
Tainted: [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
==================================================================
vhci_hcd vhci_hcd.0: Device attached