batman_adv: batadv0: The MTU of interface veth4593 is too small (1500) to handle the transport of batman-adv packets. Packets going over this interface will be fragmented on layer2 which could impact the performance. Setting the MTU to 1560 would solve the problem.
batman_adv: batadv0: Interface activated: veth4593
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BUG: KCSAN: data-race in netlink_getname / netlink_insert

write to 0xffff888050b752f8 of 4 bytes by task 21855 on cpu 0:
 netlink_insert+0x11f/0xa00 net/netlink/af_netlink.c:568
 netlink_autobind.isra.0+0xf8/0x170 net/netlink/af_netlink.c:831
 netlink_sendmsg+0x696/0x8b0 net/netlink/af_netlink.c:1880
 sock_sendmsg_nosec net/socket.c:639 [inline]
 sock_sendmsg+0x9f/0xc0 net/socket.c:659
 ____sys_sendmsg+0x49d/0x4d0 net/socket.c:2330
 ___sys_sendmsg+0xb5/0x100 net/socket.c:2384
 __sys_sendmsg+0xa0/0x160 net/socket.c:2417
 __do_sys_sendmsg net/socket.c:2426 [inline]
 __se_sys_sendmsg net/socket.c:2424 [inline]
 __x64_sys_sendmsg+0x51/0x70 net/socket.c:2424
 do_syscall_64+0xcc/0x3a0 arch/x86/entry/common.c:294
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

read to 0xffff888050b752f8 of 4 bytes by task 21860 on cpu 1:
 netlink_getname+0xfb/0x1b0 net/netlink/af_netlink.c:1116
 __sys_getsockname+0xbd/0x1a0 net/socket.c:1895
 __do_sys_getsockname net/socket.c:1910 [inline]
 __se_sys_getsockname net/socket.c:1907 [inline]
 __x64_sys_getsockname+0x4c/0x60 net/socket.c:1907
 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: 1 PID: 21860 Comm: syz-executor.5 Not tainted 5.5.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
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