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BUG: KCSAN: data-race in _prb_read_valid / prb_reserve

write to 0xffffffff866c4f50 of 8 bytes by task 15167 on cpu 0:
 prb_reserve+0x740/0xb60
 vprintk_store+0x558/0x870 kernel/printk/printk.c:2326
 vprintk_emit+0x15e/0x680 kernel/printk/printk.c:2408
 dev_vprintk_emit+0x1df/0x210 drivers/base/core.c:4935
 dev_printk_emit+0x82/0xb0 drivers/base/core.c:4946
 __netdev_printk+0x352/0x3e0 net/core/dev.c:11940
 netdev_info+0x99/0xc0 net/core/dev.c:11995
 nsim_udp_tunnel_unset_port+0x1bc/0x1e0 drivers/net/netdevsim/udp_tunnels.c:64
 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_del_port+0x1c3/0x240 net/ipv4/udp_tunnel_nic.c:548
 udp_tunnel_nic_del_port include/net/udp_tunnel.h:359 [inline]
 udp_tunnel_notify_del_rx_port+0x126/0x190 net/ipv4/udp_tunnel_core.c:148
 __geneve_sock_release drivers/net/geneve.c:631 [inline]
 geneve_sock_release+0x220/0x250 drivers/net/geneve.c:650
 geneve_stop+0xf8/0x110 drivers/net/geneve.c:741
 __dev_close_many+0x127/0x1e0 net/core/dev.c:1560
 __dev_close net/core/dev.c:1572 [inline]
 __dev_change_flags+0x366/0x410 net/core/dev.c:8949
 dev_change_flags+0x59/0xd0 net/core/dev.c:9023
 do_setlink+0x6ca/0x22c0 net/core/rtnetlink.c:3109
 rtnl_group_changelink net/core/rtnetlink.c:3737 [inline]
 __rtnl_newlink net/core/rtnetlink.c:3884 [inline]
 rtnl_newlink+0xcf9/0x1250 net/core/rtnetlink.c:4012
 rtnetlink_rcv_msg+0x651/0x710 net/core/rtnetlink.c:6922
 netlink_rcv_skb+0x12c/0x230 net/netlink/af_netlink.c:2542
 rtnetlink_rcv+0x1c/0x30 net/core/rtnetlink.c:6949
 netlink_unicast_kernel net/netlink/af_netlink.c:1321 [inline]
 netlink_unicast+0x599/0x670 net/netlink/af_netlink.c:1347
 netlink_sendmsg+0x5cc/0x6e0 net/netlink/af_netlink.c:1891
 sock_sendmsg_nosec net/socket.c:711 [inline]
 __sock_sendmsg+0x140/0x180 net/socket.c:726
 ____sys_sendmsg+0x312/0x410 net/socket.c:2583
 ___sys_sendmsg net/socket.c:2637 [inline]
 __sys_sendmsg+0x19d/0x230 net/socket.c:2669
 __do_sys_sendmsg net/socket.c:2674 [inline]
 __se_sys_sendmsg net/socket.c:2672 [inline]
 __x64_sys_sendmsg+0x46/0x50 net/socket.c:2672
 x64_sys_call+0x2734/0x2dc0 arch/x86/include/generated/asm/syscalls_64.h:47
 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 0xffffffff866c4f50 of 8 bytes by task 2989 on cpu 1:
 desc_read kernel/printk/printk_ringbuffer.c:486 [inline]
 desc_read_finalized_seq kernel/printk/printk_ringbuffer.c:1874 [inline]
 prb_read kernel/printk/printk_ringbuffer.c:1922 [inline]
 _prb_read_valid+0x1ec/0xba0 kernel/printk/printk_ringbuffer.c:2113
 prb_read_valid+0x3d/0x60 kernel/printk/printk_ringbuffer.c:2182
 syslog_print+0x26f/0x760 kernel/printk/printk.c:1650
 do_syslog+0x3a1/0x7f0 kernel/printk/printk.c:1785
 __do_sys_syslog kernel/printk/printk.c:1877 [inline]
 __se_sys_syslog kernel/printk/printk.c:1875 [inline]
 __x64_sys_syslog+0x43/0x50 kernel/printk/printk.c:1875
 x64_sys_call+0x29be/0x2dc0 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: 0x00000000000048e6 -> 0x0000000000000000

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 2989 Comm: klogd Not tainted 6.13.0-rc5-syzkaller-00161-g63676eefb7a0 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
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