smc: removing ib device syz2
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BUG: KCSAN: data-race in data_alloc / data_push_tail

write to 0xffffffff88e6bc60 of 8 bytes by task 16009 on cpu 1:
 data_alloc+0x203/0x2b0 kernel/printk/printk_ringbuffer.c:1082
 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
 usb_gadget_register_driver_owner+0x17e/0x1a0 drivers/usb/gadget/udc/core.c:1710
 raw_ioctl_run drivers/usb/gadget/legacy/raw_gadget.c:595 [inline]
 raw_ioctl+0xc5c/0x1dc0 drivers/usb/gadget/legacy/raw_gadget.c:1306
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:907 [inline]
 __se_sys_ioctl+0xcb/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 0xffffffff88e6bc60 of 8 bytes by task 4864 on cpu 0:
 data_make_reusable kernel/printk/printk_ringbuffer.c:594 [inline]
 data_push_tail+0xfd/0x420 kernel/printk/printk_ringbuffer.c:679
 data_alloc+0xbf/0x2b0 kernel/printk/printk_ringbuffer.c:1054
 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
 smc_ib_remove_dev+0x20c/0x270 net/smc/smc_ib.c:994
 remove_client_context+0x9c/0x1a0 drivers/infiniband/core/device.c:775
 disable_device+0xca/0x260 drivers/infiniband/core/device.c:1281
 __ib_unregister_device+0x1fb/0x2d0 drivers/infiniband/core/device.c:1518
 ib_unregister_work+0x19/0x30 drivers/infiniband/core/device.c:1630
 process_one_work kernel/workqueue.c:3238 [inline]
 process_scheduled_works+0x4cb/0x9d0 kernel/workqueue.c:3321
 worker_thread+0x582/0x770 kernel/workqueue.c:3402
 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

value changed: 0x000000010000061a -> 0x0000000100001214

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 4864 Comm: kworker/u8:8 Not tainted 6.16.0-rc6-syzkaller-00279-gbf61759db409 #0 PREEMPT(voluntary) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Workqueue: ib-unreg-wq ib_unregister_work
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