# CVE-2024-36902: ipv6: fib6_rules: avoid possible NULL dereference in fib6_rule_action()

> A NULL pointer dereference in the Linux kernel IPv6 routing code allows local attackers to cause a system crash.

- **Severity:** Medium 5.5 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 30 May 2024
- **Updated:** 15 Oct 2026
- **Also known as:** AZL-42468, AZL-42487, BELL-CVE-2024-36902, DEBIAN-CVE-2024-36902, UBUNTU-CVE-2024-36902

## What is CVE-2024-36902?

CVE-2024-36902 is a medium-severity vulnerability in Linux kernel, published on 30 May 2024. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

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

ipv6: fib6_rules: avoid possible NULL dereference in fib6_rule_action()

syzbot is able to trigger the following crash [1],
caused by unsafe ip6_dst_idev() use.

Indeed ip6_dst_idev() can return NULL, and must always be checked.

[1]

Oops: general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] PREEMPT SMP KASAN PTI
KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007]
CPU: 0 PID: 31648 Comm: syz-executor.0 Not tainted 6.9.0-rc4-next-20240417-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
 RIP: 0010:__fib6_rule_action net/ipv6/fib6_rules.c:237 [inline]
 RIP: 0010:fib6_rule_action+0x241/0x7b0 net/ipv6/fib6_rules.c:267
Code: 02 00 00 49 8d 9f d8 00 00 00 48 89 d8 48 c1 e8 03 42 80 3c 20 00 74 08 48 89 df e8 f9 32 bf f7 48 8b 1b 48 89 d8 48 c1 e8 03 <42> 80 3c 20 00 74 08 48 89 df e8 e0 32 bf f7 4c 8b 03 48 89 ef 4c
RSP: 0018:ffffc9000fc1f2f0 EFLAGS: 00010246
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 1a772f98c8186700
RDX: 0000000000000003 RSI: ffffffff8bcac4e0 RDI: ffffffff8c1f9760
RBP: ffff8880673fb980 R08: ffffffff8fac15ef R09: 1ffffffff1f582bd
R10: dffffc0000000000 R11: fffffbfff1f582be R12: dffffc0000000000
R13: 0000000000000080 R14: ffff888076509000 R15: ffff88807a029a00
FS:  00007f55e82ca6c0(0000) GS:ffff8880b9400000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b31d23000 CR3: 0000000022b66000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
  fib_rules_lookup+0x62c/0xdb0 net/core/fib_rules.c:317
  fib6_rule_lookup+0x1fd/0x790 net/ipv6/fib6_rules.c:108
  ip6_route_output_flags_noref net/ipv6/route.c:2637 [inline]
  ip6_route_output_flags+0x38e/0x610 net/ipv6/route.c:2649
  ip6_route_output include/net/ip6_route.h:93 [inline]
  ip6_dst_lookup_tail+0x189/0x11a0 net/ipv6/ip6_output.c:1120
  ip6_dst_lookup_flow+0xb9/0x180 net/ipv6/ip6_output.c:1250
  sctp_v6_get_dst+0x792/0x1e20 net/sctp/ipv6.c:326
  sctp_transport_route+0x12c/0x2e0 net/sctp/transport.c:455
  sctp_assoc_add_peer+0x614/0x15c0 net/sctp/associola.c:662
  sctp_connect_new_asoc+0x31d/0x6c0 net/sctp/socket.c:1099
  __sctp_connect+0x66d/0xe30 net/sctp/socket.c:1197
  sctp_connect net/sctp/socket.c:4819 [inline]
  sctp_inet_connect+0x149/0x1f0 net/sctp/socket.c:4834
  __sys_connect_file net/socket.c:2048 [inline]
  __sys_connect+0x2df/0x310 net/socket.c:2065
  __do_sys_connect net/socket.c:2075 [inline]
  __se_sys_connect net/socket.c:2072 [inline]
  __x64_sys_connect+0x7a/0x90 net/socket.c:2072
  do_syscall_x64 arch/x86/entry/common.c:52 [inline]
  do_syscall_64+0xf5/0x240 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Weakness: CWE-476 (NULL Pointer Dereference)

## Which versions are affected by CVE-2024-36902?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2024-36902?

Apply the vendor's patch.

## Is CVE-2024-36902 being exploited?

There is no known exploitation of CVE-2024-36902 in the wild and no public exploit code.

## Other vulnerabilities in Linux kernel

- [CVE-2026-53266](https://insights.sbomify.com/CVE-2026-53266/): Linux Kernel Out-of-Bounds Write (high 8.8, exploited in the wild)
- [CVE-2013-6282](https://insights.sbomify.com/CVE-2013-6282/): Linux Kernel Improper Input Validation (high 8.8, exploited in the wild)
- [CVE-2022-0185](https://insights.sbomify.com/CVE-2022-0185/): Linux Kernel Heap-Based Buffer Overflow (high 8.4, exploited in the wild)
- [CVE-2013-2094](https://insights.sbomify.com/CVE-2013-2094/): Linux Kernel Privilege Escalation (high 8.4, exploited in the wild)
- [CVE-2026-53362](https://insights.sbomify.com/CVE-2026-53362/): Linux Kernel Unspecified (high 7.8, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2024-36902 and fix it if it is affected.

What it is: CVE-2024-36902 is a medium-severity vulnerability in Linux kernel, published on 30 May 2024. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2024-36902 in the wild and no public exploit code.

Affected product: Linux kernel. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2024-36902/ (Markdown: https://insights.sbomify.com/CVE-2024-36902/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2024-36902
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2024-36902
- OSV: https://osv.dev/vulnerability/CVE-2024-36902

---
From sbomify Insights: https://insights.sbomify.com/CVE-2024-36902/
Summaries are generated and may contain mistakes; the official description above is the record.