# CVE-2024-56639: net: hsr: must allocate more bytes for RedBox support

> A memory corruption flaw in the Linux kernel HSR driver allows attackers to cause a system crash via improper buffer allocation.

- **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:** 27 Dec 2024
- **Updated:** 14 Sep 2026
- **Also known as:** BELL-CVE-2024-56639, DEBIAN-CVE-2024-56639, GHSA-j8x8-x8hr-gp48, ROOT-OS-UBUNTU-2204-CVE-2024-56639, ROOT-OS-UBUNTU-2404-CVE-2024-56639, UBUNTU-CVE-2024-56639

## What is CVE-2024-56639?

CVE-2024-56639 is a medium-severity memory corruption vulnerability in Linux kernel, published on 27 Dec 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:

net: hsr: must allocate more bytes for RedBox support

Blamed commit forgot to change hsr_init_skb() to allocate
larger skb for RedBox case.

Indeed, send_hsr_supervision_frame() will add
two additional components (struct hsr_sup_tlv
and struct hsr_sup_payload)

syzbot reported the following crash:
skbuff: skb_over_panic: text:ffffffff8afd4b0a len:34 put:6 head:ffff88802ad29e00 data:ffff88802ad29f22 tail:0x144 end:0x140 dev:gretap0
------------[ cut here ]------------
 kernel BUG at net/core/skbuff.c:206 !
Oops: invalid opcode: 0000 [#1] PREEMPT SMP KASAN NOPTI
CPU: 2 UID: 0 PID: 7611 Comm: syz-executor Not tainted 6.12.0-syzkaller #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
 RIP: 0010:skb_panic+0x157/0x1d0 net/core/skbuff.c:206
Code: b6 04 01 84 c0 74 04 3c 03 7e 21 8b 4b 70 41 56 45 89 e8 48 c7 c7 a0 7d 9b 8c 41 57 56 48 89 ee 52 4c 89 e2 e8 9a 76 79 f8 90 <0f> 0b 4c 89 4c 24 10 48 89 54 24 08 48 89 34 24 e8 94 76 fb f8 4c
RSP: 0018:ffffc90000858ab8 EFLAGS: 00010282
RAX: 0000000000000087 RBX: ffff8880598c08c0 RCX: ffffffff816d3e69
RDX: 0000000000000000 RSI: ffffffff816de786 RDI: 0000000000000005
RBP: ffffffff8c9b91c0 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000302 R11: ffffffff961cc1d0 R12: ffffffff8afd4b0a
R13: 0000000000000006 R14: ffff88804b938130 R15: 0000000000000140
FS:  000055558a3d6500(0000) GS:ffff88806a800000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f1295974ff8 CR3: 000000002ab6e000 CR4: 0000000000352ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
  skb_over_panic net/core/skbuff.c:211 [inline]
  skb_put+0x174/0x1b0 net/core/skbuff.c:2617
  send_hsr_supervision_frame+0x6fa/0x9e0 net/hsr/hsr_device.c:342
  hsr_proxy_announce+0x1a3/0x4a0 net/hsr/hsr_device.c:436
  call_timer_fn+0x1a0/0x610 kernel/time/timer.c:1794
  expire_timers kernel/time/timer.c:1845 [inline]
  __run_timers+0x6e8/0x930 kernel/time/timer.c:2419
  __run_timer_base kernel/time/timer.c:2430 [inline]
  __run_timer_base kernel/time/timer.c:2423 [inline]
  run_timer_base+0x111/0x190 kernel/time/timer.c:2439
  run_timer_softirq+0x1a/0x40 kernel/time/timer.c:2449
  handle_softirqs+0x213/0x8f0 kernel/softirq.c:554
  __do_softirq kernel/softirq.c:588 [inline]
  invoke_softirq kernel/softirq.c:428 [inline]
  __irq_exit_rcu kernel/softirq.c:637 [inline]
  irq_exit_rcu+0xbb/0x120 kernel/softirq.c:649
  instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1049 [inline]
  sysvec_apic_timer_interrupt+0xa4/0xc0 arch/x86/kernel/apic/apic.c:1049
 </IRQ>

## Which versions are affected by CVE-2024-56639?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2024-56639?

Apply the vendor's patch.

## Is CVE-2024-56639 being exploited?

There is no known exploitation of CVE-2024-56639 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-2024-56639 and fix it if it is affected.

What it is: CVE-2024-56639 is a medium-severity memory corruption vulnerability in Linux kernel, published on 27 Dec 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-2024-56639 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-2024-56639/ (Markdown: https://insights.sbomify.com/CVE-2024-56639/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2024-56639
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2024-56639
- OSV: https://osv.dev/vulnerability/CVE-2024-56639

---
From sbomify Insights: https://insights.sbomify.com/CVE-2024-56639/
Summaries are generated and may contain mistakes; the official description above is the record.