syzbot

Can not set IPV6_FL_F_REFLECT if flowlabel_consistency sysctl is enable
veth0_to_bridge: entered promiscuous mode
==================================================================
BUG: KCSAN: data-race in fib_table_lookup / fib_table_lookup

read to 0xffff888128986592 of 1 bytes by task 13128 on cpu 1:
 fib_alias_accessed net/ipv4/fib_lookup.h:31 [inline]
 fib_table_lookup+0x32c/0xd50 net/ipv4/fib_trie.c:1591
 fib_lookup include/net/ip_fib.h:385 [inline]
 ip_route_output_key_hash_rcu+0x3a1/0x12d0 net/ipv4/route.c:2735
 ip_route_output_key_hash net/ipv4/route.c:2625 [inline]
 __ip_route_output_key include/net/route.h:140 [inline]
 ip_route_output_flow+0x76/0x120 net/ipv4/route.c:2853
 udp_sendmsg+0xe5d/0x12f0 net/ipv4/udp.c:1234
 udpv6_sendmsg+0x774/0x1590 net/ipv6/udp.c:1399
 inet6_sendmsg+0xaf/0xd0 net/ipv6/af_inet6.c:661
 sock_sendmsg_nosec net/socket.c:730 [inline]
 __sock_sendmsg+0x8b/0x180 net/socket.c:745
 ____sys_sendmsg+0x312/0x410 net/socket.c:2585
 ___sys_sendmsg net/socket.c:2639 [inline]
 __sys_sendmmsg+0x269/0x500 net/socket.c:2725
 __do_sys_sendmmsg net/socket.c:2754 [inline]
 __se_sys_sendmmsg net/socket.c:2751 [inline]
 __x64_sys_sendmmsg+0x57/0x70 net/socket.c:2751
 x64_sys_call+0xa87/0x2d70 arch/x86/include/generated/asm/syscalls_64.h:308
 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

write to 0xffff888128986592 of 1 bytes by task 13127 on cpu 0:
 fib_alias_accessed net/ipv4/fib_lookup.h:32 [inline]
 fib_table_lookup+0x355/0xd50 net/ipv4/fib_trie.c:1591
 fib_lookup include/net/ip_fib.h:385 [inline]
 ip_route_output_key_hash_rcu+0x3a1/0x12d0 net/ipv4/route.c:2735
 ip_route_output_key_hash net/ipv4/route.c:2625 [inline]
 __ip_route_output_key include/net/route.h:140 [inline]
 ip_route_output_flow+0x76/0x120 net/ipv4/route.c:2853
 udp_sendmsg+0xe5d/0x12f0 net/ipv4/udp.c:1234
 udpv6_sendmsg+0x774/0x1590 net/ipv6/udp.c:1399
 inet6_sendmsg+0xaf/0xd0 net/ipv6/af_inet6.c:661
 sock_sendmsg_nosec net/socket.c:730 [inline]
 __sock_sendmsg+0x8b/0x180 net/socket.c:745
 ____sys_sendmsg+0x312/0x410 net/socket.c:2585
 ___sys_sendmsg net/socket.c:2639 [inline]
 __sys_sendmmsg+0x269/0x500 net/socket.c:2725
 __do_sys_sendmmsg net/socket.c:2754 [inline]
 __se_sys_sendmmsg net/socket.c:2751 [inline]
 __x64_sys_sendmmsg+0x57/0x70 net/socket.c:2751
 x64_sys_call+0xa87/0x2d70 arch/x86/include/generated/asm/syscalls_64.h:308
 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: 0x00 -> 0x01

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 13127 Comm: syz.0.3151 Not tainted 6.10.0-rc6-syzkaller-00061-ge9d22f7a6655 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/07/2024
==================================================================