# CVE-2024-56648: net: hsr: avoid potential out-of-bound access in fill_frame_info()

> A local attacker can trigger an out-of-bounds read in the Linux kernel HSR module, potentially causing a crash or leaking uninitialized memory.

- **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:** 23 May 2026
- **Also known as:** AZL-54785, AZL-54818, BELL-CVE-2024-56648, DEBIAN-CVE-2024-56648, GHSA-x8gq-4mj9-v7xj, SUSE-SU-2025:0889-1, SUSE-SU-2025:0910-1, SUSE-SU-2025:0937-1, SUSE-SU-2025:0949-1, UBUNTU-CVE-2024-56648

## What is CVE-2024-56648?

CVE-2024-56648 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: avoid potential out-of-bound access in fill_frame_info()

syzbot is able to feed a packet with 14 bytes, pretending
it is a vlan one.

Since fill_frame_info() is relying on skb->mac_len already,
extend the check to cover this case.

BUG: KMSAN: uninit-value in fill_frame_info net/hsr/hsr_forward.c:709 [inline]
 BUG: KMSAN: uninit-value in hsr_forward_skb+0x9ee/0x3b10 net/hsr/hsr_forward.c:724
  fill_frame_info net/hsr/hsr_forward.c:709 [inline]
  hsr_forward_skb+0x9ee/0x3b10 net/hsr/hsr_forward.c:724
  hsr_dev_xmit+0x2f0/0x350 net/hsr/hsr_device.c:235
  __netdev_start_xmit include/linux/netdevice.h:5002 [inline]
  netdev_start_xmit include/linux/netdevice.h:5011 [inline]
  xmit_one net/core/dev.c:3590 [inline]
  dev_hard_start_xmit+0x247/0xa20 net/core/dev.c:3606
  __dev_queue_xmit+0x366a/0x57d0 net/core/dev.c:4434
  dev_queue_xmit include/linux/netdevice.h:3168 [inline]
  packet_xmit+0x9c/0x6c0 net/packet/af_packet.c:276
  packet_snd net/packet/af_packet.c:3146 [inline]
  packet_sendmsg+0x91ae/0xa6f0 net/packet/af_packet.c:3178
  sock_sendmsg_nosec net/socket.c:711 [inline]
  __sock_sendmsg+0x30f/0x380 net/socket.c:726
  __sys_sendto+0x594/0x750 net/socket.c:2197
  __do_sys_sendto net/socket.c:2204 [inline]
  __se_sys_sendto net/socket.c:2200 [inline]
  __x64_sys_sendto+0x125/0x1d0 net/socket.c:2200
  x64_sys_call+0x346a/0x3c30 arch/x86/include/generated/asm/syscalls_64.h:45
  do_syscall_x64 arch/x86/entry/common.c:52 [inline]
  do_syscall_64+0xcd/0x1e0 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Uninit was created at:
  slab_post_alloc_hook mm/slub.c:4091 [inline]
  slab_alloc_node mm/slub.c:4134 [inline]
  kmem_cache_alloc_node_noprof+0x6bf/0xb80 mm/slub.c:4186
  kmalloc_reserve+0x13d/0x4a0 net/core/skbuff.c:587
  __alloc_skb+0x363/0x7b0 net/core/skbuff.c:678
  alloc_skb include/linux/skbuff.h:1323 [inline]
  alloc_skb_with_frags+0xc8/0xd00 net/core/skbuff.c:6612
  sock_alloc_send_pskb+0xa81/0xbf0 net/core/sock.c:2881
  packet_alloc_skb net/packet/af_packet.c:2995 [inline]
  packet_snd net/packet/af_packet.c:3089 [inline]
  packet_sendmsg+0x74c6/0xa6f0 net/packet/af_packet.c:3178
  sock_sendmsg_nosec net/socket.c:711 [inline]
  __sock_sendmsg+0x30f/0x380 net/socket.c:726
  __sys_sendto+0x594/0x750 net/socket.c:2197
  __do_sys_sendto net/socket.c:2204 [inline]
  __se_sys_sendto net/socket.c:2200 [inline]
  __x64_sys_sendto+0x125/0x1d0 net/socket.c:2200
  x64_sys_call+0x346a/0x3c30 arch/x86/include/generated/asm/syscalls_64.h:45
  do_syscall_x64 arch/x86/entry/common.c:52 [inline]
  do_syscall_64+0xcd/0x1e0 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Weakness: CWE-908 (Use of Uninitialized Resource)

## Which versions are affected by CVE-2024-56648?

It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `kernel-livepatch-SLE15-SP4_Update_34` | SUSE:Linux Enterprise Live Patching 15 SP4 | All versions | 3-150400.2.1 |
| `kernel-livepatch-SLE15-SP4_Update_35` | SUSE:Linux Enterprise Live Patching 15 SP4 | All versions | 3-150400.2.1 |
| `kernel-livepatch-SLE15-SP5_Update_21` | SUSE:Linux Enterprise Live Patching 15 SP5 | All versions | 2-150500.2.1 |
| `kernel-livepatch-SLE15-SP6-RT_Update_6` | SUSE:Linux Enterprise Live Patching 15 SP6 | All versions | 2-150600.2.1 |
| `kernel-livepatch-SLE15-SP6_Update_6` | SUSE:Linux Enterprise Live Patching 15 SP6 | All versions | 2-150600.2.1 |

Products: Linux kernel.

## How do I fix CVE-2024-56648?

Apply the vendor's patch.

## Is CVE-2024-56648 being exploited?

There is no known exploitation of CVE-2024-56648 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-2024-56648 and fix it if it is affected.

What it is: CVE-2024-56648 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-2024-56648 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-2024-56648/ (Markdown: https://insights.sbomify.com/CVE-2024-56648/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2024-56648
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2024-56648
- OSV: https://osv.dev/vulnerability/CVE-2024-56648

---
From sbomify Insights: https://insights.sbomify.com/CVE-2024-56648/
Summaries are generated and may contain mistakes; the official description above is the record.
