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BUG: KCSAN: data-race in _prb_read_valid / prb_reserve

write to 0xffffffff866ffaa8 of 8 bytes by task 32418 on cpu 1:
 prb_reserve+0x740/0xb60
 vprintk_store+0x53f/0x810 kernel/printk/printk.c:2301
 vprintk_emit+0x15e/0x680 kernel/printk/printk.c:2383
 dev_vprintk_emit+0x1df/0x210 drivers/base/core.c:4942
 dev_printk_emit+0x82/0xb0 drivers/base/core.c:4953
 __netdev_printk+0x352/0x3e0 net/core/dev.c:11817
 netdev_info+0x99/0xc0 net/core/dev.c:11872
 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:128
 geneve_socket_create drivers/net/geneve.c:609 [inline]
 geneve_sock_add+0x389/0x5b0 drivers/net/geneve.c:684
 geneve_open+0xc1/0x100 drivers/net/geneve.c:726
 __dev_open+0x1f7/0x2e0 net/core/dev.c:1476
 __dev_change_flags+0x155/0x410 net/core/dev.c:8845
 dev_change_flags+0x59/0xd0 net/core/dev.c:8917
 do_setlink+0x844/0x2490 net/core/rtnetlink.c:2929
 __rtnl_newlink net/core/rtnetlink.c:3725 [inline]
 rtnl_newlink+0x11a3/0x1690 net/core/rtnetlink.c:3772
 rtnetlink_rcv_msg+0x6aa/0x710 net/core/rtnetlink.c:6675
 netlink_rcv_skb+0x12c/0x230 net/netlink/af_netlink.c:2536
 rtnetlink_rcv+0x1c/0x30 net/core/rtnetlink.c:6693
 netlink_unicast_kernel net/netlink/af_netlink.c:1316 [inline]
 netlink_unicast+0x599/0x670 net/netlink/af_netlink.c:1342
 netlink_sendmsg+0x5cc/0x6e0 net/netlink/af_netlink.c:1886
 sock_sendmsg_nosec net/socket.c:729 [inline]
 __sock_sendmsg+0x140/0x180 net/socket.c:744
 __sys_sendto+0x1d6/0x260 net/socket.c:2214
 __do_sys_sendto net/socket.c:2226 [inline]
 __se_sys_sendto net/socket.c:2222 [inline]
 __x64_sys_sendto+0x78/0x90 net/socket.c:2222
 x64_sys_call+0x2959/0x2d60 arch/x86/include/generated/asm/syscalls_64.h:45
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xc9/0x1c0 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffffffff866ffaa8 of 8 bytes by task 3009 on cpu 0:
 desc_read kernel/printk/printk_ringbuffer.c:486 [inline]
 prb_first_seq kernel/printk/printk_ringbuffer.c:1957 [inline]
 _prb_read_valid+0x3bb/0xba0 kernel/printk/printk_ringbuffer.c:2114
 prb_read_valid+0x3d/0x60 kernel/printk/printk_ringbuffer.c:2182
 syslog_print+0x157/0x760 kernel/printk/printk.c:1614
 do_syslog+0x397/0x7e0 kernel/printk/printk.c:1766
 __do_sys_syslog kernel/printk/printk.c:1858 [inline]
 __se_sys_syslog kernel/printk/printk.c:1856 [inline]
 __x64_sys_syslog+0x43/0x50 kernel/printk/printk.c:1856
 x64_sys_call+0x1677/0x2d60 arch/x86/include/generated/asm/syscalls_64.h:104
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xc9/0x1c0 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0x000000000000338b -> 0x000000000000538b

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 3009 Comm: klogd Not tainted 6.12.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/30/2024
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