ref_tracker: memory allocation failure, unreliable refcount tracker.
==================================================================
BUG: KCSAN: data-race in ip_vs_add_service / ip_vs_out_hook

write to 0xffff888104338804 of 4 bytes by task 9198 on cpu 0:
 ip_vs_add_service+0x9e8/0xa50 net/netfilter/ipvs/ip_vs_ctl.c:1487
 do_ip_vs_set_ctl+0x758/0x910 net/netfilter/ipvs/ip_vs_ctl.c:2807
 nf_setsockopt+0x195/0x1b0 net/netfilter/nf_sockopt.c:101
 ip_setsockopt+0xea/0x100 net/ipv4/ip_sockglue.c:1424
 udp_setsockopt+0x95/0xb0 net/ipv4/udp.c:3058
 sock_common_setsockopt+0x64/0x80 net/core/sock.c:3894
 do_sock_setsockopt net/socket.c:2296 [inline]
 __sys_setsockopt+0x187/0x200 net/socket.c:2321
 __do_sys_setsockopt net/socket.c:2327 [inline]
 __se_sys_setsockopt net/socket.c:2324 [inline]
 __x64_sys_setsockopt+0x66/0x80 net/socket.c:2324
 x64_sys_call+0x2a09/0x2e10 arch/x86/include/generated/asm/syscalls_64.h:55
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xc9/0x1a0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffff888104338804 of 4 bytes by task 9195 on cpu 1:
 ip_vs_out_hook+0x1c7/0x910 net/netfilter/ipvs/ip_vs_core.c:1356
 nf_hook_entry_hookfn include/linux/netfilter.h:154 [inline]
 nf_hook_slow+0x89/0x1b0 net/netfilter/core.c:626
 nf_hook include/linux/netfilter.h:269 [inline]
 __ip_local_out+0x2d4/0x300 net/ipv4/ip_output.c:118
 ip_local_out net/ipv4/ip_output.c:127 [inline]
 ip_send_skb+0x30/0x140 net/ipv4/ip_output.c:1501
 udp_send_skb+0x6c2/0xa10 net/ipv4/udp.c:1195
 udp_sendmsg+0x12b4/0x1350 net/ipv4/udp.c:1483
 inet_sendmsg+0xaf/0xd0 net/ipv4/af_inet.c:851
 sock_sendmsg_nosec net/socket.c:712 [inline]
 __sock_sendmsg+0x102/0x180 net/socket.c:727
 ____sys_sendmsg+0x350/0x4e0 net/socket.c:2566
 ___sys_sendmsg net/socket.c:2620 [inline]
 __sys_sendmmsg+0x22a/0x4b0 net/socket.c:2709
 __do_sys_sendmmsg net/socket.c:2736 [inline]
 __se_sys_sendmmsg net/socket.c:2733 [inline]
 __x64_sys_sendmmsg+0x57/0x70 net/socket.c:2733
 x64_sys_call+0x2b53/0x2e10 arch/x86/include/generated/asm/syscalls_64.h:308
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xc9/0x1a0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0x00000000 -> 0x00000001

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 9195 Comm: syz.1.1925 Not tainted 6.15.0-rc2-syzkaller-00404-g8560697b23dc #0 PREEMPT(voluntary) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
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IPVS: wlc: UDP 224.0.0.2:0 - no destination available