CVE-2026-43441

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

net: bonding: Fix nd_tbl NULL dereference when IPv6 is disabled

When booting with the 'ipv6.disable=1' parameter, the nd_tbl is never

initialized because inet6_init() exits before ndisc_init() is called

which initializes it. If bonding ARP/NS validation is enabled, an IPv6

NS/NA packet received on a slave can reach bond_validate_na(), which

calls bond_has_this_ip6(). That path calls ipv6_chk_addr() and can

crash in __ipv6_chk_addr_and_flags().

BUG: kernel NULL pointer dereference, address: 00000000000005d8

Oops: Oops: 0000 [#1] SMP NOPTI

RIP: 0010:__ipv6_chk_addr_and_flags+0x69/0x170

Call Trace:

<IRQ>

ipv6_chk_addr+0x1f/0x30

bond_validate_na+0x12e/0x1d0 [bonding]

? __pfx_bond_handle_frame+0x10/0x10 [bonding]

bond_rcv_validate+0x1a0/0x450 [bonding]

bond_handle_frame+0x5e/0x290 [bonding]

? srso_alias_return_thunk+0x5/0xfbef5

__netif_receive_skb_core.constprop.0+0x3e8/0xe50

? srso_alias_return_thunk+0x5/0xfbef5

? update_cfs_rq_load_avg+0x1a/0x240

? srso_alias_return_thunk+0x5/0xfbef5

? __enqueue_entity+0x5e/0x240

__netif_receive_skb_one_core+0x39/0xa0

process_backlog+0x9c/0x150

__napi_poll+0x30/0x200

? srso_alias_return_thunk+0x5/0xfbef5

net_rx_action+0x338/0x3b0

handle_softirqs+0xc9/0x2a0

do_softirq+0x42/0x60

</IRQ>

<TASK>

__local_bh_enable_ip+0x62/0x70

__dev_queue_xmit+0x2d3/0x1000

? srso_alias_return_thunk+0x5/0xfbef5

? srso_alias_return_thunk+0x5/0xfbef5

? packet_parse_headers+0x10a/0x1a0

packet_sendmsg+0x10da/0x1700

? kick_pool+0x5f/0x140

? srso_alias_return_thunk+0x5/0xfbef5

? __queue_work+0x12d/0x4f0

__sys_sendto+0x1f3/0x220

__x64_sys_sendto+0x24/0x30

do_syscall_64+0x101/0xf80

? exc_page_fault+0x6e/0x170

? srso_alias_return_thunk+0x5/0xfbef5

entry_SYSCALL_64_after_hwframe+0x77/0x7f

</TASK>

Fix this by checking ipv6_mod_enabled() before dispatching IPv6 packets to

bond_na_rcv(). If IPv6 is disabled, return early from bond_rcv_validate()

and avoid the path to ipv6_chk_addr().