UBUNTU-CVE-2026-68336: Null Pointer Dereference
In the Linux kernel, the following vulnerability has been resolved: bonding: fix devconfall NULL dereference when IPv6 is disabled When booting with the 'ipv6.disable=1' parameter, the devconfall is never initialized because inet6init() exits before addrconfinit() is called which initializes it. bondsendvalidate(), however, will still call bondnssendall() even ipv6 is indeed disabled. It will lead to NULL derefence of net->ipv6.devconfall in ip6polroute(). BUG: kernel NULL pointer dereference, address: 000000000000000c [...] Workqueue: bond0 bondarpmonitor [bonding] RIP: 0010:ip6polroute+0x69/0x480 [...] Call Trace: <TASK> ? srsoreturnthunk+0x5/0x5f ? pfxip6polrouteoutput+0x10/0x10 fib6rulelookup+0xfe/0x260 ? wakeuppreempt+0x8a/0x90 ? srsoreturnthunk+0x5/0x5f ? srsoreturnthunk+0x5/0x5f ? schedbalancerq+0x369/0x810 ip6routeoutputflags+0xd7/0x170 bondnssendall+0xde/0x280 [bonding] bondabarpprobe+0x296/0x320 [bonding] ? srsoreturnthunk+0x5/0x5f bondactivebackuparpmon+0xb4/0x2c0 [bonding] processonework+0x196/0x370 workerthread+0x1af/0x320 ? srsoreturnthunk+0x5/0x5f ? pfxworkerthread+0x10/0x10 kthread+0xe3/0x120 ? pfxkthread+0x10/0x10 retfromfork+0x199/0x260 ? pfxkthread+0x10/0x10 retfromforkasm+0x1a/0x30 </TASK> Fix this by adding ipv6modenabled() condition check in the caller.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
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ubuntu/linuxto a version that resolves this vulnerability.Fixed in 6.8.0-147.147 - Upgrade
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ubuntu/linux-awsto a version that resolves this vulnerability.Fixed in 6.8.0-1067.70 - Upgrade
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ubuntu/linux-aws-7.0to a version that resolves this vulnerability.Fixed in 7.0.0-1014.14~24.04.1 - Upgrade
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ubuntu/linux-azureto a version that resolves this vulnerability.Fixed in 6.8.0-1071.79 - Upgrade
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ubuntu/linux-azure-7.0to a version that resolves this vulnerability.Fixed in 7.0.0-1017.17~24.04.1 - Upgrade
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ubuntu/linux-azure-fdeto a version that resolves this vulnerability.Fixed in 6.8.0-1069.76 - Upgrade
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ubuntu/linux-azure-fde-7.0to a version that resolves this vulnerability.Fixed in 7.0.0-1016.16~24.04.1 - Upgrade
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ubuntu/linux-gcpto a version that resolves this vulnerability.Fixed in 6.8.0-1071.79 - Upgrade
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ubuntu/linux-gcp-7.0to a version that resolves this vulnerability.Fixed in 7.0.0-1014.14~24.04.1 - Upgrade
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ubuntu/linux-gketo a version that resolves this vulnerability.Fixed in 6.8.0-1066.74 - Upgrade
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ubuntu/linux-gkeopto a version that resolves this vulnerability.Fixed in 6.8.0-1052.56 - Upgrade
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ubuntu/linux-hwe-7.0to a version that resolves this vulnerability.Fixed in 7.0.0-38.38~24.04.4 - Upgrade
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ubuntu/linux-ibmto a version that resolves this vulnerability.Fixed in 6.8.0-1067.68 - Upgrade
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ubuntu/linux-lowlatencyto a version that resolves this vulnerability.Fixed in 6.8.0-147.147.1 - Upgrade
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ubuntu/linux-oracleto a version that resolves this vulnerability.Fixed in 6.8.0-1064.67 - Upgrade
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ubuntu/linux-oracle-7.0to a version that resolves this vulnerability.Fixed in 7.0.0-1013.13~24.04.1 - Upgrade
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ubuntu/linux-riscv-7.0to a version that resolves this vulnerability.Fixed in 7.0.0-38.38.1~24.04.1 - Upgrade
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ubuntu/linux-bluefieldto a version that resolves this vulnerability.Fixed in 6.8.0-1033.38 - Upgrade
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ubuntu/linux-realtimeto a version that resolves this vulnerability.Fixed in 6.8.1-1062.63 - Upgrade
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ubuntu/linux-aws-fipsto a version that resolves this vulnerability.Fixed in 6.8.0-1067.70+fips1 - Upgrade
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ubuntu/linux-azure-fipsto a version that resolves this vulnerability.Fixed in 6.8.0-1071.79+fips1 - Upgrade
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ubuntu/linux-fipsto a version that resolves this vulnerability.Fixed in 6.8.0-147.147+fips1 - Upgrade
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ubuntu/linux-gcp-fipsto a version that resolves this vulnerability.Fixed in 6.8.0-1071.79+fips1 - Upgrade
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ubuntu/linuxto a version that resolves this vulnerability.Fixed in 7.0.0-38.38 - Upgrade
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ubuntu/linux-awsto a version that resolves this vulnerability.Fixed in 7.0.0-1014.14 - Upgrade
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ubuntu/linux-azureto a version that resolves this vulnerability.Fixed in 7.0.0-1017.17 - Upgrade
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ubuntu/linux-azure-fdeto a version that resolves this vulnerability.Fixed in 7.0.0-1016.16 - Upgrade
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ubuntu/linux-gcpto a version that resolves this vulnerability.Fixed in 7.0.0-1014.14 - Upgrade
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ubuntu/linux-gketo a version that resolves this vulnerability.Fixed in 7.0.0-1008.9 - Upgrade
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ubuntu/linux-ibmto a version that resolves this vulnerability.Fixed in 7.0.0-1015.15 - Upgrade
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ubuntu/linux-oem-7.0to a version that resolves this vulnerability.Fixed in 7.0.0-1015.15 - Upgrade
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ubuntu/linux-oracleto a version that resolves this vulnerability.Fixed in 7.0.0-1013.13 - Upgrade
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ubuntu/linux-realtimeto a version that resolves this vulnerability.Fixed in 7.0.0-38.38.1 - Upgrade
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ubuntu/linux-riscvto a version that resolves this vulnerability.Fixed in 7.0.0-38.38.1 - Compensating control
Add an ipv6_mod_enabled() condition check in the caller so IPv6-dependent routing operations are not invoked when IPv6 is disabled, preventing the devconf_all NULL dereference.
Event History
Frequently Asked Questions
Which Ubuntu kernel packages are listed as affected?
The listed packages are ubuntu/linux-riscv, ubuntu/linux-realtime, ubuntu/linux-azure, ubuntu/linux-gcp, ubuntu/linux-azure-fde, ubuntu/linux-gke, ubuntu/linux-hwe-edge, and ubuntu/linux-gkeop.
What runtime conditions are associated with the crash?
The issue occurs when the system is booted with ipv6.disable=1, leaving net->ipv6.devconf_all uninitialized. Bonding code can still perform a route operation through bond_ns_send_all(), including from the bond_arp_monitor workqueue.
How can an administrator recognize that this issue has occurred?
The reported symptom is a kernel NULL pointer dereference at address 000000000000000c in ip6_pol_route(). The call trace includes ip6_route_output_flags, bond_ns_send_all, bond_ab_arp_probe, and bond_activebackup_arp_mon.