Cloudanix VulnDB

CVE-2026-68336

None

CVSS

—

EPSS

0.2%

Published

Aug 10, 2026

CISA due date

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Cloudanix analysis

Schedule a fix SSVC: Track

A Linux network setup error can make servers crash when a common feature is turned off, causing unexpected downtime.

Exploitation
Local Privilege
Attacker needs
Local User
Complexity
Low
Impact
Denial Of Service
Component
OS kernel
Class
Memory Corruption
Remediation
Upgrade
Effort
Medium
Patch risk
Low

What it actually does

NULL pointer dereference in ip6_pol_route when bonding module invokes bond_ns_send_all without checking if IPv6 is disabled, causing kernel panic during ARP monitoring workqueue.

Why it matters to the business

Systems using network bonding with IPv6 disabled at boot experience kernel crashes and reboots, resulting in unplanned downtime for servers and network appliances.

How an attack unfolds

The flaw is triggered automatically by normal bonding ARP monitor operation after boot with ipv6.disable=1; no remote attacker is required as the condition leads directly to NULL dereference in the IPv6 routing lookup path called from the bonding driver.

How to fix it

Apply a kernel update containing the fix that adds an ipv6_mod_enabled() guard before calling bond_ns_send_all in the bonding ARP path; rebuild and reboot with the patched kernel.

How to confirm the fix worked

Confirm presence of the ipv6_mod_enabled() check in bond_send_validate or equivalent bonding source; test boot with ipv6.disable=1 and active bonding interface to verify absence of NULL dereference panic.

Typical attack path

  1. Boot kernel with ipv6.disable=1 parameter
  2. Configure and activate a bonding interface
  3. Allow bond_activebackup_arp_mon workqueue to invoke bond_ab_arp_probe
  4. Reach bond_ns_send_all which calls into ip6_route_output_flags without IPv6 module check
  5. Trigger NULL dereference in ip6_pol_route

How to detect it

Search kernel logs and crash dumps for stack traces containing ip6_pol_route, bond_ns_send_all, bond_arp_monitor, and references to net->ipv6.devconf_all; correlate with boot-time ipv6.disable parameter usage.

  • ip6_pol_route+0x69/0x480
  • bond_ns_send_all+0xde/0x280
  • bond_ab_arp_probe
  • bond_activebackup_arp_mon
  • BUG: kernel NULL pointer dereference.*ipv6.devconf_all

What your security team should do

  • Prioritize patching all systems using the bonding module
  • Review kernel boot parameters for ipv6.disable usage
  • Monitor for kernel oops reports involving bonding and IPv6 routing functions
  • Consider enabling IPv6 if operationally feasible to avoid the disabled code path

The record

In the Linux kernel, the following vulnerability has been resolved: bonding: fix devconf_all NULL dereference when IPv6 is disabled When booting with the 'ipv6.disable=1' parameter, the devconf_all is never initialized because inet6_init() exits before addrconf_init() is called which initializes it. bond_send_validate(), however, will still call bond_ns_send_all() even ipv6 is indeed disabled. It will lead to NULL derefence of net->ipv6.devconf_all in ip6_pol_route(). BUG: kernel NULL pointer dereference, address: 000000000000000c [...] Workqueue: bond0 bond_arp_monitor [bonding] RIP: 0010:ip6_pol_route+0x69/0x480 [...] Call Trace: <TASK> ? srso_return_thunk+0x5/0x5f ? __pfx_ip6_pol_route_output+0x10/0x10 fib6_rule_lookup+0xfe/0x260 ? wakeup_preempt+0x8a/0x90 ? srso_return_thunk+0x5/0x5f ? srso_return_thunk+0x5/0x5f ? sched_balance_rq+0x369/0x810 ip6_route_output_flags+0xd7/0x170 bond_ns_send_all+0xde/0x280 [bonding] bond_ab_arp_probe+0x296/0x320 [bonding] ? srso_return_thunk+0x5/0x5f bond_activebackup_arp_mon+0xb4/0x2c0 [bonding] process_one_work+0x196/0x370 worker_thread+0x1af/0x320 ? srso_return_thunk+0x5/0x5f ? __pfx_worker_thread+0x10/0x10 kthread+0xe3/0x120 ? __pfx_kthread+0x10/0x10 ret_from_fork+0x199/0x260 ? __pfx_kthread+0x10/0x10 ret_from_fork_asm+0x1a/0x30 </TASK> Fix this by adding ipv6_mod_enabled() condition check in the caller.

Affected packages

Ecosystem Package Introduced Fixed