syzbot

netlink: 'syz.0.1226': attribute type 10 has an invalid length.
8021q: adding VLAN 0 to HW filter on device bond0
8021q: adding VLAN 0 to HW filter on device team0
==================================================================
BUG: KASAN: global-out-of-bounds in __hw_addr_create net/core/dev_addr_lists.c:63 [inline]
BUG: KASAN: global-out-of-bounds in __hw_addr_add_ex+0x27f/0x770 net/core/dev_addr_lists.c:118
Read of size 16 at addr ffffffff8c1abd60 by task syz.0.1226/10644

CPU: 1 UID: 0 PID: 10644 Comm: syz.0.1226 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
Call Trace:
 <TASK>
 dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:378 [inline]
 print_report+0xca/0x240 mm/kasan/report.c:482
 kasan_report+0x118/0x150 mm/kasan/report.c:595
 check_region_inline mm/kasan/generic.c:-1 [inline]
 kasan_check_range+0x2b0/0x2c0 mm/kasan/generic.c:189
 __asan_memcpy+0x29/0x70 mm/kasan/shadow.c:105
 __hw_addr_create net/core/dev_addr_lists.c:63 [inline]
 __hw_addr_add_ex+0x27f/0x770 net/core/dev_addr_lists.c:118
 __dev_mc_add net/core/dev_addr_lists.c:868 [inline]
 dev_mc_add+0xa1/0x120 net/core/dev_addr_lists.c:886
 bond_enslave+0x2c78/0x3a20 drivers/net/bonding/bond_main.c:2368
 do_set_master+0x533/0x6d0 net/core/rtnetlink.c:2948
 do_setlink+0xcf0/0x41c0 net/core/rtnetlink.c:3150
 rtnl_changelink net/core/rtnetlink.c:3761 [inline]
 __rtnl_newlink net/core/rtnetlink.c:3920 [inline]
 rtnl_newlink+0x160b/0x1c70 net/core/rtnetlink.c:4057
 rtnetlink_rcv_msg+0x7cf/0xb70 net/core/rtnetlink.c:6946
 netlink_rcv_skb+0x205/0x470 net/netlink/af_netlink.c:2552
 netlink_unicast_kernel net/netlink/af_netlink.c:1320 [inline]
 netlink_unicast+0x82c/0x9e0 net/netlink/af_netlink.c:1346
 netlink_sendmsg+0x805/0xb30 net/netlink/af_netlink.c:1896
 sock_sendmsg_nosec net/socket.c:714 [inline]
 __sock_sendmsg+0x21c/0x270 net/socket.c:729
 ____sys_sendmsg+0x505/0x830 net/socket.c:2614
 ___sys_sendmsg+0x21f/0x2a0 net/socket.c:2668
 __sys_sendmsg net/socket.c:2700 [inline]
 __do_sys_sendmsg net/socket.c:2705 [inline]
 __se_sys_sendmsg net/socket.c:2703 [inline]
 __x64_sys_sendmsg+0x19b/0x260 net/socket.c:2703
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f246598ebe9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 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 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f2466828038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f2465bc5fa0 RCX: 00007f246598ebe9
RDX: 0000000000000000 RSI: 0000200000000600 RDI: 0000000000000003
RBP: 00007f2465a11e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f2465bc6038 R14: 00007f2465bc5fa0 R15: 00007ffd09a08b38
 </TASK>

The buggy address belongs to the variable:
 lacpdu_mcast_addr+0x0/0x40

The buggy address belongs to the physical page:
page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0xc1ab
flags: 0xfff00000002000(reserved|node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000002000 ffffea0000306ac8 ffffea0000306ac8 0000000000000000
raw: 0000000000000000 0000000000000000 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner info is not present (never set?)

Memory state around the buggy address:
 ffffffff8c1abc00: f9 f9 f9 f9 00 00 00 00 00 00 00 00 00 f9 f9 f9
 ffffffff8c1abc80: f9 f9 f9 f9 00 00 00 00 00 00 00 00 00 00 00 00
>ffffffff8c1abd00: 00 00 00 00 00 00 00 00 f9 f9 f9 f9 00 f9 f9 f9
                                                          ^
 ffffffff8c1abd80: 00 00 00 00 00 00 00 00 00 00 04 f9 f9 f9 f9 f9
 ffffffff8c1abe00: 00 f9 f9 f9 00 00 06 f9 f9 f9 f9 f9 00 00 00 00
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