================================================================== BUG: KCSAN: data-race in data_alloc / prb_reserve write to 0xffffffff868955c0 of 8 bytes by task 28489 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+0x4ab/0x5f0 drivers/usb/usbip/vhci_rx.c:265 kthread+0x489/0x510 kernel/kthread.c:463 ret_from_fork+0x11f/0x1b0 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 read to 0xffffffff868955c0 of 8 bytes by task 28491 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 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+0x4ab/0x5f0 drivers/usb/usbip/vhci_rx.c:265 kthread+0x489/0x510 kernel/kthread.c:463 ret_from_fork+0x11f/0x1b0 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 value changed: 0x0000000000054840 -> 0x00000000000f19d0 Reported by Kernel Concurrency Sanitizer on: CPU: 0 UID: 0 PID: 28491 Comm: vhci_rx Tainted: G W syzkaller #0 PREEMPT(voluntary) Tainted: [W]=WARN Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 ================================================================== vhci_hcd: connection closed