Vulnerability record · CVE-2026-43441 · published 8 May 2026
CVE-2026-43441: Linux kernel null pointer dereference vulnerability
Linux · Linux Kernel
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().
Description
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().
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Affected products
1 vulnerable configurations from NVD's CPE data, grouped by vendor and product.
References
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Related vulnerabilities
Same products first, then exploited flaws of the same weakness class.
Source: NIST National Vulnerability Database (record CVE-2026-43441), CISA KEV, FIRST EPSS (scores of 2026-09-26). This page is refreshed as NVD updates the record.