netlink: 'syz-executor4': attribute type 16 has an invalid length.
==================================================================
BUG: KMSAN: kernel-infoleak in copyout lib/iov_iter.c:140 [inline]
BUG: KMSAN: kernel-infoleak in _copy_to_iter+0x4a2/0x2690 lib/iov_iter.c:571
CPU: 0 PID: 15884 Comm: syz-executor2 Not tainted 4.19.0+ #78
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x32d/0x480 lib/dump_stack.c:113
 kmsan_report+0x19f/0x300 mm/kmsan/kmsan.c:911
 kmsan_internal_check_memory+0x2b3/0x450 mm/kmsan/kmsan.c:967
 kmsan_copy_to_user+0x7c/0xe0 mm/kmsan/kmsan_hooks.c:552
 copyout lib/iov_iter.c:140 [inline]
 _copy_to_iter+0x4a2/0x2690 lib/iov_iter.c:571
 copy_to_iter include/linux/uio.h:106 [inline]
 skb_copy_datagram_iter+0x4e2/0x1070 net/core/datagram.c:431
 skb_copy_datagram_msg include/linux/skbuff.h:3279 [inline]
 netlink_recvmsg+0x6f9/0x19d0 net/netlink/af_netlink.c:1966
 sock_recvmsg_nosec net/socket.c:794 [inline]
 sock_recvmsg net/socket.c:801 [inline]
 __sys_recvfrom+0x6d3/0x910 net/socket.c:1845
 __do_sys_recvfrom net/socket.c:1863 [inline]
 __se_sys_recvfrom+0x111/0x130 net/socket.c:1859
 __x64_sys_recvfrom+0x6e/0x90 net/socket.c:1859
 do_syscall_64+0xcf/0x110 arch/x86/entry/common.c:291
 entry_SYSCALL_64_after_hwframe+0x63/0xe7
RIP: 0033:0x457569
Code: fd b3 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 cb b3 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007f261e74ac78 EFLAGS: 00000246 ORIG_RAX: 000000000000002d
RAX: ffffffffffffffda RBX: 0000000000000006 RCX: 0000000000457569
RDX: fffffffffffffeef RSI: 0000000020000000 RDI: 0000000000000005
RBP: 000000000072bf00 R08: 0000000020000100 R09: 00000000000003e5
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f261e74b6d4
R13: 00000000004c3460 R14: 00000000004d5260 R15: 00000000ffffffff

Uninit was stored to memory at:
 kmsan_save_stack_with_flags mm/kmsan/kmsan.c:252 [inline]
 kmsan_save_stack mm/kmsan/kmsan.c:267 [inline]
 kmsan_internal_chain_origin+0x136/0x240 mm/kmsan/kmsan.c:569
 kmsan_memcpy_origins+0x13d/0x1b0 mm/kmsan/kmsan.c:393
 __msan_memcpy+0x6f/0x80 mm/kmsan/kmsan_instr.c:242
 __nla_put lib/nlattr.c:569 [inline]
 nla_put+0x20a/0x2d0 lib/nlattr.c:627
 nlmsg_populate_fdb_fill+0x444/0x810 net/core/rtnetlink.c:3396
 nlmsg_populate_fdb net/core/rtnetlink.c:3695 [inline]
 ndo_dflt_fdb_dump+0x73a/0x960 net/core/rtnetlink.c:3727
 rtnl_fdb_dump+0xc0c/0x13a0 net/core/rtnetlink.c:3826
 netlink_dump+0xb09/0x1750 net/netlink/af_netlink.c:2233
 __netlink_dump_start+0x100b/0x1110 net/netlink/af_netlink.c:2329
 netlink_dump_start include/linux/netlink.h:213 [inline]
 rtnetlink_rcv_msg+0x141b/0x1540 net/core/rtnetlink.c:4693
 netlink_rcv_skb+0x394/0x640 net/netlink/af_netlink.c:2454
 rtnetlink_rcv+0x50/0x60 net/core/rtnetlink.c:4748
 netlink_unicast_kernel net/netlink/af_netlink.c:1317 [inline]
 netlink_unicast+0x1699/0x1740 net/netlink/af_netlink.c:1343
 netlink_sendmsg+0x13c7/0x1440 net/netlink/af_netlink.c:1908
 sock_sendmsg_nosec net/socket.c:621 [inline]
 sock_sendmsg net/socket.c:631 [inline]
 ___sys_sendmsg+0xe68/0x1250 net/socket.c:2116
 __sys_sendmsg net/socket.c:2154 [inline]
 __do_sys_sendmsg net/socket.c:2163 [inline]
 __se_sys_sendmsg+0x305/0x460 net/socket.c:2161
 __x64_sys_sendmsg+0x4a/0x70 net/socket.c:2161
 do_syscall_64+0xcf/0x110 arch/x86/entry/common.c:291
 entry_SYSCALL_64_after_hwframe+0x63/0xe7

Uninit was created at:
 kmsan_save_stack_with_flags mm/kmsan/kmsan.c:252 [inline]
 kmsan_internal_poison_shadow+0xc8/0x1e0 mm/kmsan/kmsan.c:177
 kmsan_kmalloc+0x98/0x110 mm/kmsan/kmsan_hooks.c:104
 __kmalloc+0x14c/0x4d0 mm/slub.c:3789
 kmalloc include/linux/slab.h:518 [inline]
 __hw_addr_create_ex net/core/dev_addr_lists.c:34 [inline]
 __hw_addr_add_ex net/core/dev_addr_lists.c:80 [inline]
 __dev_mc_add+0x357/0x8a0 net/core/dev_addr_lists.c:670
 dev_mc_add+0x6d/0x80 net/core/dev_addr_lists.c:687
 garp_init_applicant+0x26a/0x910 net/802/garp.c:577
 vlan_gvrp_init_applicant+0x50/0x60 net/8021q/vlan_gvrp.c:54
 register_vlan_dev+0x439/0xd20 net/8021q/vlan.c:159
 register_vlan_device net/8021q/vlan.c:273 [inline]
 vlan_ioctl_handler+0x1518/0x1870 net/8021q/vlan.c:614
 sock_ioctl+0xaec/0xe00 net/socket.c:1052
 do_vfs_ioctl+0xf77/0x2d30 fs/ioctl.c:46
 ksys_ioctl fs/ioctl.c:702 [inline]
 __do_sys_ioctl fs/ioctl.c:709 [inline]
 __se_sys_ioctl+0x1da/0x270 fs/ioctl.c:707
 __x64_sys_ioctl+0x4a/0x70 fs/ioctl.c:707
 do_syscall_64+0xcf/0x110 arch/x86/entry/common.c:291
 entry_SYSCALL_64_after_hwframe+0x63/0xe7

Bytes 1016-1021 of 3744 are uninitialized
Memory access of size 3744 starts at ffff88012aa09000
Data copied to user address 0000000020000000
==================================================================