syzbot

batman_adv: The newly added mac address (aa:aa:aa:aa:aa:3e) already exists on: batadv_slave_1
batman_adv: It is strongly recommended to keep mac addresses unique to avoid problems!
batman_adv: The newly added mac address (aa:aa:aa:aa:aa:3e) already exists on: batadv_slave_1
batman_adv: It is strongly recommended to keep mac addresses unique to avoid problems!
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BUG: KCSAN: data-race in batadv_check_known_mac_addr / batadv_iv_ogm_schedule_buff

write to 0xffff88809e0a0c10 of 1 bytes by task 7 on cpu 1:
 batadv_iv_ogm_schedule_buff+0x86/0x820 net/batman-adv/bat_iv_ogm.c:799
 batadv_iv_ogm_schedule net/batman-adv/bat_iv_ogm.c:865 [inline]
 batadv_iv_ogm_schedule net/batman-adv/bat_iv_ogm.c:858 [inline]
 batadv_iv_send_outstanding_bat_ogm_packet+0x212/0x510 net/batman-adv/bat_iv_ogm.c:1718
 process_one_work+0x413/0x8f0 kernel/workqueue.c:2264
 worker_thread+0xa0/0x800 kernel/workqueue.c:2410
 kthread+0x1d4/0x200 drivers/block/aoe/aoecmd.c:1253
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:352

read to 0xffff88809e0a0c10 of 1 bytes by task 29397 on cpu 0:
 batadv_check_known_mac_addr+0x81/0x1a0 net/batman-adv/hard-interface.c:505
 batadv_hard_if_event+0x348/0xa70 net/batman-adv/hard-interface.c:1062
 notifier_call_chain+0xd7/0x160 kernel/notifier.c:83
 __raw_notifier_call_chain kernel/notifier.c:361 [inline]
 raw_notifier_call_chain+0x37/0x50 kernel/notifier.c:368
 call_netdevice_notifiers_info net/core/dev.c:1943 [inline]
 call_netdevice_notifiers_info+0x9a/0x120 net/core/dev.c:1928
 call_netdevice_notifiers_extack net/core/dev.c:1955 [inline]
 call_netdevice_notifiers net/core/dev.c:1969 [inline]
 dev_set_mac_address net/core/dev.c:8414 [inline]
 dev_set_mac_address+0x1df/0x240 net/core/dev.c:8395
 do_setlink+0x3dc/0x1ee0 net/core/rtnetlink.c:2551
 __rtnl_newlink+0x956/0x10a0 net/core/rtnetlink.c:3252
 rtnl_newlink+0x63/0x90 net/core/rtnetlink.c:3377
 rtnetlink_rcv_msg+0x1d3/0x500 net/core/rtnetlink.c:5438
 netlink_rcv_skb+0xb0/0x260 net/netlink/af_netlink.c:2477
 rtnetlink_rcv+0x26/0x30 net/core/rtnetlink.c:5456
 netlink_unicast_kernel net/netlink/af_netlink.c:1302 [inline]
 netlink_unicast+0x3a6/0x4d0 net/netlink/af_netlink.c:1328
 netlink_sendmsg+0x4d3/0x8b0 net/netlink/af_netlink.c:1917
 sock_sendmsg_nosec net/socket.c:652 [inline]
 sock_sendmsg+0x9f/0xc0 net/socket.c:672
 __sys_sendto+0x21f/0x320 net/socket.c:1998
 __do_sys_sendto net/socket.c:2010 [inline]
 __se_sys_sendto net/socket.c:2006 [inline]
 __x64_sys_sendto+0x89/0xb0 net/socket.c:2006
 do_syscall_64+0xcc/0x3a0 arch/x86/entry/common.c:294
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 29397 Comm: syz-executor.5 Not tainted 5.6.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
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