sock_sendmsg_nosec net/socket.c:646 [inline]
 sock_sendmsg+0xc5/0x100 net/socket.c:656
------------[ cut here ]------------
 ___sys_sendmsg+0x70a/0x840 net/socket.c:2062
WARNING: CPU: 0 PID: 2335 at net/batman-adv/bat_iv_ogm.c:555 batadv_iv_ogm_emit net/batman-adv/bat_iv_ogm.c:555 [inline]
WARNING: CPU: 0 PID: 2335 at net/batman-adv/bat_iv_ogm.c:555 batadv_iv_send_outstanding_bat_ogm_packet+0x5b6/0x6a0 net/batman-adv/bat_iv_ogm.c:1797
Kernel panic - not syncing: panic_on_warn set ...

 __sys_sendmsg+0xa3/0x120 net/socket.c:2096
 SYSC_sendmsg net/socket.c:2107 [inline]
 SyS_sendmsg+0x27/0x40 net/socket.c:2103
 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x45c479
RSP: 002b:00007f028c781c78 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f028c7826d4 RCX: 000000000045c479
RDX: 0000000000000000 RSI: 0000000020000080 RDI: 0000000000000006
RBP: 000000000076c060 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000008
R13: 00000000000009f9 R14: 00000000004cc71a R15: 0000000000000005
CPU: 0 PID: 2335 Comm: kworker/u4:4 Not tainted 4.14.172-syzkaller #0
batman_adv: batadv0: Adding interface: veth271
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: bat_events batadv_iv_send_outstanding_bat_ogm_packet
batman_adv: batadv0: The MTU of interface veth271 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.
Call Trace:
 __dump_stack lib/dump_stack.c:17 [inline]
 dump_stack+0x13e/0x194 lib/dump_stack.c:58
 panic+0x1f9/0x42d kernel/panic.c:183
batman_adv: batadv0: Not using interface veth271 (retrying later): interface not active
 __warn.cold+0x2f/0x30 kernel/panic.c:547
 report_bug+0x20a/0x248 lib/bug.c:186
 fixup_bug arch/x86/kernel/traps.c:177 [inline]
 fixup_bug arch/x86/kernel/traps.c:172 [inline]
 do_error_trap+0x195/0x2d0 arch/x86/kernel/traps.c:295
batman_adv: batadv0: Adding interface: veth233
batman_adv: batadv0: The MTU of interface veth233 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.
 invalid_op+0x1b/0x40 arch/x86/entry/entry_64.S:963
RIP: 0010:batadv_iv_ogm_emit net/batman-adv/bat_iv_ogm.c:555 [inline]
RIP: 0010:batadv_iv_send_outstanding_bat_ogm_packet+0x5b6/0x6a0 net/batman-adv/bat_iv_ogm.c:1797
RSP: 0018:ffff8880a15ffce8 EFLAGS: 00010297
batman_adv: batadv0: Not using interface veth233 (retrying later): interface not active
RAX: ffff8880a161c300 RBX: ffff8880a91d1188 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffffffff87d84360 RDI: ffff888096c325e8
RBP: ffff888053015e40 R08: 000000000000387b R09: ffffffff8a077c98
R10: ffff8880a161cba8 R11: ffff8880a161c300 R12: ffff888096c32580
R13: ffff8880a91d1140 R14: ffff888092d18ac0 R15: ffff8880a91d1228
 process_one_work+0x813/0x1540 kernel/workqueue.c:2114
batman_adv: batadv0: Adding interface: veth217
batman_adv: batadv0: The MTU of interface veth217 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.
 worker_thread+0x5d1/0x1070 kernel/workqueue.c:2248
batman_adv: batadv0: Not using interface veth217 (retrying later): interface not active
 kthread+0x30d/0x420 kernel/kthread.c:232
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404
Kernel Offset: disabled
Rebooting in 86400 seconds..