CVE-2026-23099

In the Linux kernel, the following vulnerability has been resolved:

bonding: limit BOND_MODE_8023AD to Ethernet devices

BOND_MODE_8023AD makes sense for ARPHRD_ETHER only.

syzbot reported:

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+0x25d/0x760 net/core/dev_addr_lists.c:118

Read of size 16 at addr ffffffff8bf94040 by task syz.1.3580/19497

CPU: 1 UID: 0 PID: 19497 Comm: syz.1.3580 Tainted: G L syzkaller #0 PREEMPT(full)

Tainted: [L]=SOFTLOCKUP

Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025

Call Trace:

<TASK>

dump_stack_lvl+0xe8/0x150 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:200

__asan_memcpy+0x29/0x70 mm/kasan/shadow.c:105

__hw_addr_create net/core/dev_addr_lists.c:63 [inline]

__hw_addr_add_ex+0x25d/0x760 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+0x2b8b/0x3ac0 drivers/net/bonding/bond_main.c:2180

do_set_master+0x533/0x6d0 net/core/rtnetlink.c:2963

do_setlink+0xcf0/0x41c0 net/core/rtnetlink.c:3165

rtnl_changelink net/core/rtnetlink.c:3776 [inline]

__rtnl_newlink net/core/rtnetlink.c:3935 [inline]

rtnl_newlink+0x161c/0x1c90 net/core/rtnetlink.c:4072

rtnetlink_rcv_msg+0x7cf/0xb70 net/core/rtnetlink.c:6958

netlink_rcv_skb+0x208/0x470 net/netlink/af_netlink.c:2550

netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline]

netlink_unicast+0x82f/0x9e0 net/netlink/af_netlink.c:1344

netlink_sendmsg+0x805/0xb30 net/netlink/af_netlink.c:1894

sock_sendmsg_nosec net/socket.c:727 [inline]

__sock_sendmsg+0x21c/0x270 net/socket.c:742

____sys_sendmsg+0x505/0x820 net/socket.c:2592

___sys_sendmsg+0x21f/0x2a0 net/socket.c:2646

__sys_sendmsg+0x164/0x220 net/socket.c:2678

do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline]

__do_fast_syscall_32+0x1dc/0x560 arch/x86/entry/syscall_32.c:307

do_fast_syscall_32+0x34/0x80 arch/x86/entry/syscall_32.c:332

entry_SYSENTER_compat_after_hwframe+0x84/0x8e

</TASK>

The buggy address belongs to the variable:

lacpdu_mcast_addr+0x0/0x40