---
id: CVE-2024-40961
title: |-
  In the Linux kernel, the following vulnerability has been resolved:

  ipv6: prevent possible NULL deref in fib6_nh_init()

  syzbot reminds us that in6_dev_get() can return NULL.

  fib6_nh_init()
      ip6_validate_gw(  &idev  )
          ip6_ro…
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  ipv6: prevent possible NULL deref in fib6_nh_init()

  syzbot reminds us that in6_dev_get() can return NULL.

  fib6_nh_init()
      ip6_validate_gw(  &idev  )
          ip6_ro…
severity: medium
cvss: 5.5
cvssVector: 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H'
cwe:
  - CWE-476
vendor: linux
product: linux_kernel
affected:
  - 'linux_kernel >= 4.17, < 5.4.279'
  - 'linux_kernel >= 5.5, < 5.10.221'
  - 'linux_kernel >= 5.11, < 5.15.162'
  - 'linux_kernel >= 5.16, < 6.1.96'
  - 'linux_kernel >= 6.2, < 6.6.36'
  - 'linux_kernel >= 6.7, < 6.9.7'
  - linux_kernel = 6.10
patched:
  - linux_kernel 6.9.7
published: '2024-07-12'
updated: '2026-10-15'
sourceUpdated: '2026-10-15T01:18:39.123'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2024-40961'
references:
  - url: 'https://git.kernel.org/stable/c/2eab4543a2204092c3a7af81d7d6c506e59a03a6'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/3200ffeec4d59aad5bc9ca75d2c1fae47c0aeade'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/4cdfe813015d5a24586bd0a84fa0fa6eb0a1f668'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/88b9a55e2e35ea846d41f4efdc29d23345bd1aa4'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/ae8d3d39efe366c2198f530e01e4bf07830bf403'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/b6947723c9eabcab58cfb33cdb0a565a6aee6727'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/de5ad4d45cd0128a2a37555f48ab69aa19d78adc'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/2eab4543a2204092c3a7af81d7d6c506e59a03a6'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://git.kernel.org/stable/c/3200ffeec4d59aad5bc9ca75d2c1fae47c0aeade'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://git.kernel.org/stable/c/4cdfe813015d5a24586bd0a84fa0fa6eb0a1f668'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://git.kernel.org/stable/c/88b9a55e2e35ea846d41f4efdc29d23345bd1aa4'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://git.kernel.org/stable/c/ae8d3d39efe366c2198f530e01e4bf07830bf403'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://git.kernel.org/stable/c/b6947723c9eabcab58cfb33cdb0a565a6aee6727'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://git.kernel.org/stable/c/de5ad4d45cd0128a2a37555f48ab69aa19d78adc'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://lists.debian.org/debian-lts-announce/2025/01/msg00001.html'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://cert-portal.siemens.com/productcert/html/ssa-265688.html'
    label: 0b142b55-0307-4c5a-b3c9-f314f3fb7c5e
  - url: 'https://cert-portal.siemens.com/productcert/html/ssa-355557.html'
    label: 0b142b55-0307-4c5a-b3c9-f314f3fb7c5e
  - url: 'https://cert-portal.siemens.com/productcert/html/ssa-613116.html'
    label: 0b142b55-0307-4c5a-b3c9-f314f3fb7c5e
tags:
  - nvd
  - cve.org
epss: 0.00268
epssPercentile: 0.18801
ingestedAt: '2026-10-15T03:30:12.723Z'
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: partial
  timestamp: '2024-09-10T17:03:26.191957Z'
---

## Overview

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

ipv6: prevent possible NULL deref in fib6_nh_init()

syzbot reminds us that in6_dev_get() can return NULL.

fib6_nh_init()
    ip6_validate_gw(  &idev  )
        ip6_route_check_nh(  idev  )
            *idev = in6_dev_get(dev); // can be NULL

Oops: general protection fault, probably for non-canonical address 0xdffffc00000000bc: 0000 [#1] PREEMPT SMP KASAN PTI
KASAN: null-ptr-deref in range [0x00000000000005e0-0x00000000000005e7]
CPU: 0 PID: 11237 Comm: syz-executor.3 Not tainted 6.10.0-rc2-syzkaller-00249-gbe27b8965297 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/07/2024
 RIP: 0010:fib6_nh_init+0x640/0x2160 net/ipv6/route.c:3606
Code: 00 00 fc ff df 4c 8b 64 24 58 48 8b 44 24 28 4c 8b 74 24 30 48 89 c1 48 89 44 24 28 48 8d 98 e0 05 00 00 48 89 d8 48 c1 e8 03 <42> 0f b6 04 38 84 c0 0f 85 b3 17 00 00 8b 1b 31 ff 89 de e8 b8 8b
RSP: 0018:ffffc900032775a0 EFLAGS: 00010202
RAX: 00000000000000bc RBX: 00000000000005e0 RCX: 0000000000000000
RDX: 0000000000000010 RSI: ffffc90003277a54 RDI: ffff88802b3a08d8
RBP: ffffc900032778b0 R08: 00000000000002fc R09: 0000000000000000
R10: 00000000000002fc R11: 0000000000000000 R12: ffff88802b3a08b8
R13: 1ffff9200064eec8 R14: ffffc90003277a00 R15: dffffc0000000000
FS:  00007f940feb06c0(0000) GS:ffff8880b9400000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 00000000245e8000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
  ip6_route_info_create+0x99e/0x12b0 net/ipv6/route.c:3809
  ip6_route_add+0x28/0x160 net/ipv6/route.c:3853
  ipv6_route_ioctl+0x588/0x870 net/ipv6/route.c:4483
  inet6_ioctl+0x21a/0x280 net/ipv6/af_inet6.c:579
  sock_do_ioctl+0x158/0x460 net/socket.c:1222
  sock_ioctl+0x629/0x8e0 net/socket.c:1341
  vfs_ioctl fs/ioctl.c:51 [inline]
  __do_sys_ioctl fs/ioctl.c:907 [inline]
  __se_sys_ioctl+0xfc/0x170 fs/ioctl.c:893
  do_syscall_x64 arch/x86/entry/common.c:52 [inline]
  do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f940f07cea9

## Affected

- `linux_kernel >= 4.17, < 5.4.279`
- `linux_kernel >= 5.5, < 5.10.221`
- `linux_kernel >= 5.11, < 5.15.162`
- `linux_kernel >= 5.16, < 6.1.96`
- `linux_kernel >= 6.2, < 6.6.36`
- `linux_kernel >= 6.7, < 6.9.7`
- `linux_kernel = 6.10`

## Remediation

Upgrade past the affected range:

- `linux_kernel 6.9.7`
