==================================================================
BUG: KCSAN: data-race in data_alloc / prb_reserve

write to 0xffffffff86076988 of 8 bytes by task 8284 on cpu 0:
 data_alloc+0x291/0x2c0 kernel/printk/printk_ringbuffer.c:1096
 prb_reserve+0x85e/0xb60 kernel/printk/printk_ringbuffer.c:1669
 vprintk_store+0x53f/0x810 kernel/printk/printk.c:2269
 vprintk_emit+0x10c/0x5e0 kernel/printk/printk.c:2329
 dev_vprintk_emit+0x1df/0x210 drivers/base/core.c:4930
 dev_printk_emit+0x82/0xb0 drivers/base/core.c:4941
 __netdev_printk+0x352/0x3e0 net/core/dev.c:11499
 netdev_info+0x99/0xc0 net/core/dev.c:11554
 nsim_udp_tunnel_set_port+0x175/0x190 drivers/net/netdevsim/udp_tunnels.c:34
 udp_tunnel_nic_device_sync_by_port net/ipv4/udp_tunnel_nic.c:246 [inline]
 __udp_tunnel_nic_device_sync+0x57b/0x9e0 net/ipv4/udp_tunnel_nic.c:289
 udp_tunnel_nic_device_sync net/ipv4/udp_tunnel_nic.c:312 [inline]
 __udp_tunnel_nic_add_port+0x66d/0x6e0 net/ipv4/udp_tunnel_nic.c:531
 udp_tunnel_nic_add_port include/net/udp_tunnel.h:350 [inline]
 udp_tunnel_notify_add_rx_port+0x126/0x190 net/ipv4/udp_tunnel_core.c:127
 geneve_socket_create drivers/net/geneve.c:606 [inline]
 geneve_sock_add+0x389/0x5b0 drivers/net/geneve.c:681
 geneve_open+0xc1/0x100 drivers/net/geneve.c:723
 __dev_open+0x1f7/0x2e0 net/core/dev.c:1430
 __dev_change_flags+0x155/0x410 net/core/dev.c:8686
 dev_change_flags+0x59/0xd0 net/core/dev.c:8758
 do_setlink+0x841/0x2480 net/core/rtnetlink.c:2884
 __rtnl_newlink net/core/rtnetlink.c:3680 [inline]
 rtnl_newlink+0x11a1/0x1690 net/core/rtnetlink.c:3727
 rtnetlink_rcv_msg+0x82e/0x8e0 net/core/rtnetlink.c:6595
 netlink_rcv_skb+0x12c/0x230 net/netlink/af_netlink.c:2559
 rtnetlink_rcv+0x1c/0x30 net/core/rtnetlink.c:6613
 netlink_unicast_kernel net/netlink/af_netlink.c:1335 [inline]
 netlink_unicast+0x58d/0x660 net/netlink/af_netlink.c:1361
 netlink_sendmsg+0x5d3/0x6e0 net/netlink/af_netlink.c:1905
 sock_sendmsg_nosec net/socket.c:730 [inline]
 __sock_sendmsg+0x140/0x180 net/socket.c:745
 __sys_sendto+0x1e5/0x260 net/socket.c:2191
 __do_sys_sendto net/socket.c:2203 [inline]
 __se_sys_sendto net/socket.c:2199 [inline]
 __x64_sys_sendto+0x78/0x90 net/socket.c:2199
 do_syscall_64+0xd3/0x1d0
 entry_SYSCALL_64_after_hwframe+0x72/0x7a

read to 0xffffffff86076988 of 8 bytes by task 8507 on cpu 1:
 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+0x235/0xb60 kernel/printk/printk_ringbuffer.c:1619
 vprintk_store+0x53f/0x810 kernel/printk/printk.c:2269
 vprintk_emit+0x10c/0x5e0 kernel/printk/printk.c:2329
 vprintk_default+0x26/0x30 kernel/printk/printk.c:2363
 vprintk+0x75/0x80 kernel/printk/printk_safe.c:45
 _printk+0x7a/0xa0 kernel/printk/printk.c:2373
 __nla_validate_parse+0x1769/0x1ce0 lib/nlattr.c:647
 __nla_parse+0x40/0x60 lib/nlattr.c:732
 __nlmsg_parse include/net/netlink.h:756 [inline]
 genl_family_rcv_msg_attrs_parse+0x148/0x1a0 net/netlink/genetlink.c:943
 genl_family_rcv_msg_doit net/netlink/genetlink.c:1091 [inline]
 genl_family_rcv_msg net/netlink/genetlink.c:1193 [inline]
 genl_rcv_msg+0x470/0x6c0 net/netlink/genetlink.c:1208
 netlink_rcv_skb+0x12c/0x230 net/netlink/af_netlink.c:2559
 genl_rcv+0x28/0x40 net/netlink/genetlink.c:1217
 netlink_unicast_kernel net/netlink/af_netlink.c:1335 [inline]
 netlink_unicast+0x58d/0x660 net/netlink/af_netlink.c:1361
 netlink_sendmsg+0x5d3/0x6e0 net/netlink/af_netlink.c:1905
 sock_sendmsg_nosec net/socket.c:730 [inline]
 __sock_sendmsg+0x140/0x180 net/socket.c:745
 ____sys_sendmsg+0x312/0x410 net/socket.c:2584
 ___sys_sendmsg net/socket.c:2638 [inline]
 __sys_sendmsg+0x1e9/0x280 net/socket.c:2667
 __do_sys_sendmsg net/socket.c:2676 [inline]
 __se_sys_sendmsg net/socket.c:2674 [inline]
 __x64_sys_sendmsg+0x46/0x50 net/socket.c:2674
 do_syscall_64+0xd3/0x1d0
 entry_SYSCALL_64_after_hwframe+0x72/0x7a

value changed: 0x0000000000004090 -> 0x00000000000bc838

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 8507 Comm: syz-executor.4 Not tainted 6.9.0-rc1-syzkaller-00206-g4535e1a4174c #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
==================================================================
netlink: 8 bytes leftover after parsing attributes in process `syz-executor.4'.
platform regulatory.0: Direct firmware load for regulatory.db failed with error -2