------------[ cut here ]------------
err == -EMSGSIZE
WARNING: net/core/rtnetlink.c:4538 at rtmsg_ifinfo_build_skb+0x1c1/0x260 net/core/rtnetlink.c:4538, CPU#2: syz.3.840/7755
Modules linked in:
CPU: 2 UID: 0 PID: 7755 Comm: syz.3.840 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
RIP: 0010:rtmsg_ifinfo_build_skb+0x1c1/0x260 net/core/rtnetlink.c:4538
Code: ea 03 0f b6 14 02 48 89 f8 83 e0 07 83 c0 03 38 d0 7c 08 84 d2 0f 85 80 00 00 00 45 8b 76 08 e9 3c ff ff ff e8 60 94 77 f8 90 <0f> 0b 90 ba 02 00 00 00 48 89 ee 31 ff bb a6 ff ff ff e8 58 8f f0
RSP: 0018:ffffc90003096de0 EFLAGS: 00010287
RAX: 000000000000ac42 RBX: 00000000ffffffa6 RCX: ffffc9000c001000
RDX: 0000000000080000 RSI: ffffffff89923b40 RDI: ffff88802670a540
RBP: ffff8880505ff040 R08: 0000000000000005 R09: 0000000000000000
R10: 00000000ffffffa6 R11: 0000000000000000 R12: 0000000000000002
R13: 0000000000000000 R14: 0000000000000000 R15: ffff88805d2e2108
FS:  0000000000000000(0000) GS:ffff888096df3000(0063) knlGS:00000000f53d6b40
CS:  0010 DS: 002b ES: 002b CR0: 0000000080050033
CR2: 0000000080001140 CR3: 000000004cf6f000 CR4: 0000000000352ef0
Call Trace:
 <TASK>
 rtmsg_ifinfo_event net/core/rtnetlink.c:4566 [inline]
 rtmsg_ifinfo_event net/core/rtnetlink.c:4556 [inline]
 rtnetlink_event+0x137/0x1f0 net/core/rtnetlink.c:7136
 notifier_call_chain+0x99/0x3f0 kernel/notifier.c:85
 call_netdevice_notifiers_info+0xbe/0x110 net/core/dev.c:2250
 call_netdevice_notifiers_extack net/core/dev.c:2288 [inline]
 call_netdevice_notifiers net/core/dev.c:2302 [inline]
 netdev_features_change net/core/dev.c:1590 [inline]
 netdev_update_features net/core/dev.c:11108 [inline]
 netdev_update_features net/core/dev.c:11105 [inline]
 netif_disable_lro+0x3e9/0x660 net/core/dev.c:1831
 inetdev_init+0x371/0x570 net/ipv4/devinet.c:284
 inetdev_event+0x7fa/0x17f0 net/ipv4/devinet.c:1590
 notifier_call_chain+0x99/0x3f0 kernel/notifier.c:85
 call_netdevice_notifiers_info+0xbe/0x110 net/core/dev.c:2250
 call_netdevice_notifiers_extack net/core/dev.c:2288 [inline]
 call_netdevice_notifiers net/core/dev.c:2302 [inline]
 register_netdevice+0x1998/0x25a0 net/core/dev.c:11484
 macsec_newlink+0x4fb/0x1c50 drivers/net/macsec.c:4221
 rtnl_newlink_create net/core/rtnetlink.c:3913 [inline]
 __rtnl_newlink net/core/rtnetlink.c:4044 [inline]
 rtnl_newlink+0x1499/0x2380 net/core/rtnetlink.c:4159
 rtnetlink_rcv_msg+0x95e/0xe90 net/core/rtnetlink.c:7076
 netlink_rcv_skb+0x159/0x420 net/netlink/af_netlink.c:2556
 netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline]
 netlink_unicast+0x585/0x850 net/netlink/af_netlink.c:1345
 netlink_sendmsg+0x8b0/0xda0 net/netlink/af_netlink.c:1900
 sock_sendmsg_nosec net/socket.c:775 [inline]
 __sock_sendmsg net/socket.c:790 [inline]
 ____sys_sendmsg+0xa4d/0xbe0 net/socket.c:2684
 ___sys_sendmsg+0x190/0x1e0 net/socket.c:2738
 __sys_sendmsg+0x160/0x210 net/socket.c:2770
 do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline]
 __do_fast_syscall_32+0xe7/0x970 arch/x86/entry/syscall_32.c:307
 do_fast_syscall_32+0x32/0x70 arch/x86/entry/syscall_32.c:332
 entry_SYSENTER_compat_after_hwframe+0x84/0x8e
RIP: 0023:0xf7f13fec
Code: Unable to access opcode bytes at 0xf7f13fc2.
RSP: 002b:00000000f53d650c EFLAGS: 00000292 ORIG_RAX: 0000000000000172
RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 0000000080000280
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000292 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
 </TASK>