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

write to 0xffffffff88e1e370 of 11 bytes by task 11361 on cpu 0:
 vsnprintf+0x2ce/0x890 lib/vsprintf.c:2826
 vscnprintf+0x41/0x90 lib/vsprintf.c:2939
 printk_sprint+0x30/0x2d0 kernel/printk/printk.c:2216
 vprintk_store+0x599/0x860 kernel/printk/printk.c:2336
 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
 __nla_validate_parse+0x1738/0x1d00 lib/nlattr.c:647
 __nla_parse+0x40/0x60 lib/nlattr.c:732
 __nlmsg_parse include/net/netlink.h:787 [inline]
 nlmsg_parse_deprecated include/net/netlink.h:828 [inline]
 neigh_add+0x118/0x8f0 net/core/neighbour.c:1926
 rtnetlink_rcv_msg+0x657/0x6d0 net/core/rtnetlink.c:6953
 netlink_rcv_skb+0x120/0x220 net/netlink/af_netlink.c:2552
 rtnetlink_rcv+0x1c/0x30 net/core/rtnetlink.c:6971
 netlink_unicast_kernel net/netlink/af_netlink.c:1320 [inline]
 netlink_unicast+0x5a8/0x680 net/netlink/af_netlink.c:1346
 netlink_sendmsg+0x58b/0x6b0 net/netlink/af_netlink.c:1896
 sock_sendmsg_nosec net/socket.c:712 [inline]
 __sock_sendmsg+0x145/0x180 net/socket.c:727
 ____sys_sendmsg+0x345/0x4e0 net/socket.c:2612
 ___sys_sendmsg+0x17b/0x1d0 net/socket.c:2666
 __sys_sendmmsg+0x178/0x300 net/socket.c:2755
 __do_sys_sendmmsg net/socket.c:2782 [inline]
 __se_sys_sendmmsg net/socket.c:2779 [inline]
 __x64_sys_sendmmsg+0x57/0x70 net/socket.c:2779
 x64_sys_call+0x1c4a/0x2ff0 arch/x86/include/generated/asm/syscalls_64.h:308
 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 0xffffffff88e1e370 of 8 bytes by task 3513 on cpu 1:
 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
 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:2100 [inline]
 ib_query_port+0x390/0x3d0 drivers/infiniband/core/device.c:2141
 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: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+0xdd/0x150 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

value changed: 0x00000000fffff559 -> 0x3a6b6e696c74656e

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 3513 Comm: kworker/1:5 Not tainted 6.16.0-syzkaller-04405-g4b290aae788e #0 PREEMPT(voluntary) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
Workqueue: infiniband ib_cache_event_task
==================================================================
syz0: Port: 1 Link DOWN