---
id: CVE-2026-98379
title: |-
  In the Linux kernel, the following vulnerability has been resolved:

  netfilter: ip6t_rpfilter: reject routes without inet6_dev

  ip6_route_lookup() can return an error-free route whose rt6i_idev is
  NULL
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  netfilter: ip6t_rpfilter: reject routes without inet6_dev

  ip6_route_lookup() can return an error-free route whose rt6i_idev is
  NULL. Lowering an external nexthop devic…
severity: none
published: '2026-10-09'
updated: '2026-10-09'
sourceUpdated: '2026-10-09T08:16:56.250'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-98379'
references:
  - url: 'https://git.kernel.org/stable/c/1681ab6dd1271f2f36047490793b78b1848bbcc9'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/1b9b5323725e458906c7620a3bc10398b51ad954'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/290c96e5d9471d1ded9ab1e8ffbb04f6ee7b0f40'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/3a7384bc2e66217c9a01a392281334f4423740a0'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/65487e9e99431ffcf05024a817f51ee4e3bd9b47'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/eafe081ea77d25b5c8e601680671b4ecb4520e7d'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/f49da48bd679cfee646d6a40dd02b1933de577d1'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/f4de78756b0fddbd125b2b1b77c74f2eccc8e977'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
tags:
  - nvd
ingestedAt: '2026-10-09T08:29:41.350Z'
---

## Overview

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

netfilter: ip6t_rpfilter: reject routes without inet6_dev

ip6_route_lookup() can return an error-free route whose rt6i_idev is
NULL. Lowering an external nexthop device's MTU below IPV6_MIN_MTU tears
down its inet6_dev while fib6_ifdown() leaves routes using nexthop objects
in the FIB. An unprivileged user can construct this state with rtnetlink
in a private user and network namespace, then trigger a NULL dereference
through an IPv6 rpfilter lookup:

  Oops: general protection fault, probably for non-canonical address
  0xdffffc0000000000
  KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007]
  RIP: rpfilter_mt (net/ipv6/netfilter/ip6t_rpfilter.c:75)
  Call Trace:
  ip6t_do_table (net/ipv6/netfilter/ip6_tables.c:316)
  nf_hook_slow (net/netfilter/core.c:619)
  ipv6_rcv (net/ipv6/ip6_input.c:351)
  __netif_receive_skb_one_core (net/core/dev.c:6216)
  process_backlog (net/core/dev.c:6680)
  __napi_poll (net/core/dev.c:7739)
  net_rx_action (net/core/dev.c:7959)
  handle_softirqs (kernel/softirq.c:622)
  do_softirq.part.0 (kernel/softirq.c:523)
  __local_bh_enable_ip (kernel/softirq.c:450)
  __dev_queue_xmit (net/core/dev.c:4913)
  packet_sendmsg (net/packet/af_packet.c:3139)
  __sys_sendto (net/socket.c:2252)
  __x64_sys_sendto (net/socket.c:2259)
  do_syscall_64 (arch/x86/entry/syscall_64.c:94)
  entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:121)
  Kernel panic - not syncing: Fatal exception in interrupt

Reject routes without an inet6_dev immediately after lookup. Such routes
are not eligible for reverse-path filtering, and the check protects all
later rt6i_idev dereferences.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.