Vulnerability in Kernel (CVE-2024-56635)

Summary

Vulnerability in Kernel (CVE-2024-56635). Successful exploitation can lead to full system takeover. Mitigation: upgrade to 6.6.66, 6.12.5 or later.

Original description

The description as published by the source.

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

net: avoid potential UAF in default_operstate()

syzbot reported an UAF in default_operstate() [1]

Issue is a race between device and netns dismantles.

After calling __rtnl_unlock() from netdev_run_todo(),
we can not assume the netns of each device is still alive.

Make sure the device is not in NETREG_UNREGISTERED state,
and add an ASSERT_RTNL() before the call to
__dev_get_by_index().

We might move this ASSERT_RTNL() in __dev_get_by_index()
in the future.

[1]

BUG: KASAN: slab-use-after-free in __dev_get_by_index+0x5d/0x110 net/core/dev.c:852
Read of size 8 at addr ffff888043eba1b0 by task syz.0.0/5339

CPU: 0 UID: 0 PID: 5339 Comm: syz.0.0 Not tainted 6.12.0-syzkaller-10296-gaaf20f870da0 #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
Call Trace:

__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120
print_address_description mm/kasan/report.c:378 [inline]
print_report+0x169/0x550 mm/kasan/report.c:489
kasan_report+0x143/0x180 mm/kasan/report.c:602
__dev_get_by_index+0x5d/0x110 net/core/dev.c:852
default_operstate net/core/link_watch.c:51 [inline]
rfc2863_policy+0x224/0x300 net/core/link_watch.c:67
linkwatch_do_dev+0x3e/0x170 net/core/link_watch.c:170
netdev_run_todo+0x461/0x1000 net/core/dev.c:10894
rtnl_unlock net/core/rtnetlink.c:152 [inline]
rtnl_net_unlock include/linux/rtnetlink.h:1…

Source: OSV.dev (Open Source Vulnerabilities) NVD OSV

Auto-generated summary

Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.

A vulnerability tracked as CVE-2024-56635 has been found in Kernel.
Successful exploitation can lead to full system takeover.
What to do: upgrade Kernel to 6.6.66, 6.12.5 or later.
If unsure, ask your IT team or search "Kernel CVE-2024-56635" on the vendor's site.

CVE-2024-56635 (Kernel)
Attack vector: local / no user interaction
Patched: 6.6.66, 6.12.5 — apply immediately
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.

❓ What is the problem

A vulnerability (unclassified) exists in Kernel.

📍 Affected scope

Check the vendor advisory for the affected versions of Kernel.

🔥 Severity

Severity: ?. Successful exploitation can lead to full system takeover.

🔧 How to fix

Update to 6.6.66, 6.12.5.

🛡️ Workaround

Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.

🔍 Detection

Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Run grep -r 'Kernel' . against your dependency files (package-lock.json, requirements.txt, go.sum) to find affected services.

Response actions

Concrete steps and command examples for SOC/SRE teams to execute in order

1
Identify exposure identify
```
grep -r 'Kernel' . | grep -v node_modules
```
リポジトリと本番環境の依存ファイル (package-lock.json / requirements.txt / go.sum / Gemfile.lock 等) で Kernel を grep し、稼働しているサービス・バージョンを把握する。
2
Apply patch patch
```
Upgrade Kernel to 6.6.66, 6.12.5
```
ステージング環境で 6.6.66, 6.12.5 に上げて回帰テスト → 本番反映。回帰テストはアプリの主要ハッピーパスを含めること。
3
Post-deployment verification verify
```
Confirm patched version is live in production
```
パッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。

Affected packages

Linux Kernel

[{"type":"ECOSYSTEM","events":[{"introduced":"6.2.0"},{"fixed":"6.6.66"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.7.0"},{"fixed":"6.12.5"}]}]

Fix status by distribution

Fixed packages published by each distribution for this CVE

BellSoft Alpaquita BELL-CVE-2024-56635 linux-lts Fixed in: 6.12.41-r0
Debian DEBIAN-CVE-2024-56635 linux Fixed in: 6.12.5-1
Ubuntu UBUNTU-CVE-2024-56635 linux-hwe-edge