lo speed is unknown, defaulting to 1000
==================================================================
BUG: KCSAN: data-race in data_push_tail / number

write to 0xffffffff88e527c0 of 1 bytes by task 10348 on cpu 0:
 number+0x8fd/0xab0 lib/vsprintf.c:572
 vsnprintf+0x691/0x890 lib/vsprintf.c:2890
 vscnprintf+0x41/0x90 lib/vsprintf.c:2991
 printk_sprint+0x30/0x2d0 kernel/printk/printk.c:2189
 vprintk_store+0x599/0x860 kernel/printk/printk.c:2309
 vprintk_emit+0x10d/0x580 kernel/printk/printk.c:2399
 vprintk_default+0x26/0x30 kernel/printk/printk.c:2438
 vprintk+0x1d/0x30 kernel/printk/printk_safe.c:82
 _printk+0x79/0xa0 kernel/printk/printk.c:2448
 ib_get_eth_speed+0x33d/0x4b0 drivers/infiniband/core/verbs.c:2006
 siw_query_port+0x3a/0x2d0 drivers/infiniband/sw/siw/siw_verbs.c:179
 iw_query_port drivers/infiniband/core/device.c:2137 [inline]
 ib_query_port+0x393/0x3d0 drivers/infiniband/core/device.c:2178
 ib_setup_port_attrs+0x14a/0x1430 drivers/infiniband/core/sysfs.c:1429
 add_one_compat_dev+0x261/0x360 drivers/infiniband/core/device.c:1005
 rdma_dev_init_net+0x182/0x210 drivers/infiniband/core/device.c:1221
 ops_init+0x22a/0x2e0 net/core/net_namespace.c:137
 setup_net+0x83/0x210 net/core/net_namespace.c:445
 copy_net_ns+0x28c/0x3b0 net/core/net_namespace.c:580
 create_new_namespaces+0x20e/0x3d0 kernel/nsproxy.c:110
 unshare_nsproxy_namespaces+0xe8/0x120 kernel/nsproxy.c:218
 ksys_unshare+0x3d0/0x6d0 kernel/fork.c:3129
 __do_sys_unshare kernel/fork.c:3200 [inline]
 __se_sys_unshare kernel/fork.c:3198 [inline]
 __x64_sys_unshare+0x1f/0x30 kernel/fork.c:3198
 x64_sys_call+0x2915/0x3000 arch/x86/include/generated/asm/syscalls_64.h:273
 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 0xffffffff88e527c0 of 8 bytes by task 5313 on cpu 1:
 data_make_reusable kernel/printk/printk_ringbuffer.c:591 [inline]
 data_push_tail+0xfd/0x420 kernel/printk/printk_ringbuffer.c:676
 data_alloc+0xfb/0x2e0 kernel/printk/printk_ringbuffer.c:1061
 prb_reserve+0x807/0xaf0 kernel/printk/printk_ringbuffer.c:1685
 vprintk_store+0x56d/0x860 kernel/printk/printk.c:2299
 vprintk_emit+0x10d/0x580 kernel/printk/printk.c:2399
 vprintk_default+0x26/0x30 kernel/printk/printk.c:2438
 vprintk+0x1d/0x30 kernel/printk/printk_safe.c:82
 _printk+0x79/0xa0 kernel/printk/printk.c:2448
 ib_get_eth_speed+0x33d/0x4b0 drivers/infiniband/core/verbs.c:2006
 siw_query_port+0x3a/0x2d0 drivers/infiniband/sw/siw/siw_verbs.c:179
 iw_query_port drivers/infiniband/core/device.c:2137 [inline]
 ib_query_port+0x393/0x3d0 drivers/infiniband/core/device.c:2178
 ib_cache_update+0xf8/0x700 drivers/infiniband/core/cache.c:1459
 ib_cache_event_task+0x7f/0xf0 drivers/infiniband/core/cache.c:1539
 process_one_work kernel/workqueue.c:3263 [inline]
 process_scheduled_works+0x4ce/0x9d0 kernel/workqueue.c:3346
 worker_thread+0x582/0x770 kernel/workqueue.c:3427
 kthread+0x489/0x510 kernel/kthread.c:463
 ret_from_fork+0x122/0x1b0 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

value changed: 0x00000000fffff7e5 -> 0x00000000ff000a30

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 5313 Comm: kworker/1:8 Tainted: G        W           syzkaller #0 PREEMPT(voluntary) 
Tainted: [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
Workqueue: infiniband ib_cache_event_task
==================================================================
syz2: Port: 1 Link ACTIVE