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BUG: KCSAN: data-race in batadv_hard_if_event / batadv_mcast_mla_update

write to 0xffff88810b5a5a10 of 1 bytes by task 13898 on cpu 1:
 batadv_hardif_remove_interface net/batman-adv/hard-interface.c:924 [inline]
 batadv_hard_if_event+0x838/0xf50 net/batman-adv/hard-interface.c:982
 notifier_call_chain kernel/notifier.c:85 [inline]
 raw_notifier_call_chain+0x6f/0x1d0 kernel/notifier.c:453
 call_netdevice_notifiers_info+0xae/0x100 net/core/dev.c:2180
 call_netdevice_notifiers_extack net/core/dev.c:2218 [inline]
 call_netdevice_notifiers net/core/dev.c:2232 [inline]
 unregister_netdevice_many_notify+0xd12/0x1600 net/core/dev.c:11973
 unregister_netdevice_many net/core/dev.c:12037 [inline]
 unregister_netdevice_queue+0x1fd/0x230 net/core/dev.c:11889
 unregister_netdevice include/linux/netdevice.h:3374 [inline]
 nsim_destroy+0xbd/0x340 drivers/net/netdevsim/netdev.c:1051
 __nsim_dev_port_del+0xcd/0x100 drivers/net/netdevsim/dev.c:1428
 nsim_dev_port_del_all drivers/net/netdevsim/dev.c:1440 [inline]
 nsim_dev_reload_destroy+0x1a6/0x2d0 drivers/net/netdevsim/dev.c:1661
 nsim_dev_reload_down+0x77/0xa0 drivers/net/netdevsim/dev.c:968
 devlink_reload+0xad/0x5b0 net/devlink/dev.c:461
 devlink_nl_reload_doit+0x4da/0x930 net/devlink/dev.c:584
 genl_family_rcv_msg_doit net/netlink/genetlink.c:1115 [inline]
 genl_family_rcv_msg net/netlink/genetlink.c:1195 [inline]
 genl_rcv_msg+0x69b/0x6f0 net/netlink/genetlink.c:1210
 netlink_rcv_skb+0x12f/0x230 net/netlink/af_netlink.c:2534
 genl_rcv+0x28/0x40 net/netlink/genetlink.c:1219
 netlink_unicast_kernel net/netlink/af_netlink.c:1313 [inline]
 netlink_unicast+0x605/0x6c0 net/netlink/af_netlink.c:1339
 netlink_sendmsg+0x609/0x720 net/netlink/af_netlink.c:1883
 sock_sendmsg_nosec net/socket.c:712 [inline]
 __sock_sendmsg+0x140/0x180 net/socket.c:727
 ____sys_sendmsg+0x350/0x4e0 net/socket.c:2566
 ___sys_sendmsg net/socket.c:2620 [inline]
 __sys_sendmsg+0x1a0/0x240 net/socket.c:2652
 __do_sys_sendmsg net/socket.c:2657 [inline]
 __se_sys_sendmsg net/socket.c:2655 [inline]
 __x64_sys_sendmsg+0x46/0x50 net/socket.c:2655
 x64_sys_call+0x26f3/0x2e10 arch/x86/include/generated/asm/syscalls_64.h:47
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xc9/0x1c0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffff88810b5a5a10 of 1 bytes by task 13111 on cpu 0:
 batadv_mcast_mla_forw_flags_get net/batman-adv/multicast.c:252 [inline]
 batadv_mcast_mla_flags_get net/batman-adv/multicast.c:289 [inline]
 __batadv_mcast_mla_update net/batman-adv/multicast.c:909 [inline]
 batadv_mcast_mla_update+0x21d/0x1710 net/batman-adv/multicast.c:948
 process_one_work kernel/workqueue.c:3238 [inline]
 process_scheduled_works+0x4de/0xa20 kernel/workqueue.c:3319
 worker_thread+0x52c/0x710 kernel/workqueue.c:3400
 kthread+0x4b7/0x540 kernel/kthread.c:464
 ret_from_fork+0x4b/0x60 arch/x86/kernel/process.c:153
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

value changed: 0x00 -> 0x01

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 13111 Comm: kworker/u8:12 Not tainted 6.14.0-syzkaller-13189-ge48e99b6edf4 #0 PREEMPT(voluntary) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
Workqueue: bat_events batadv_mcast_mla_update
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