# CVE-2023-53462: hsr: Fix uninit-value access in fill_frame_info()

> An uninitialized value access in the Linux kernel HSR module allows local attackers to read sensitive kernel memory.

- **Severity:** High 7.1 (`CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 1 Oct 2025
- **Updated:** 5 Aug 2026
- **Also known as:** BELL-CVE-2023-53462, DEBIAN-CVE-2023-53462, GHSA-vrfv-m2p8-gw2m, UBUNTU-CVE-2023-53462

## What is CVE-2023-53462?

CVE-2023-53462 is a high-severity vulnerability in Linux kernel, published on 1 Oct 2025. 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:

hsr: Fix uninit-value access in fill_frame_info()

Syzbot reports the following uninit-value access problem.

=====================================================
BUG: KMSAN: uninit-value in fill_frame_info net/hsr/hsr_forward.c:601 [inline]
BUG: KMSAN: uninit-value in hsr_forward_skb+0x9bd/0x30f0 net/hsr/hsr_forward.c:616
 fill_frame_info net/hsr/hsr_forward.c:601 [inline]
 hsr_forward_skb+0x9bd/0x30f0 net/hsr/hsr_forward.c:616
 hsr_dev_xmit+0x192/0x330 net/hsr/hsr_device.c:223
 __netdev_start_xmit include/linux/netdevice.h:4889 [inline]
 netdev_start_xmit include/linux/netdevice.h:4903 [inline]
 xmit_one net/core/dev.c:3544 [inline]
 dev_hard_start_xmit+0x247/0xa10 net/core/dev.c:3560
 __dev_queue_xmit+0x34d0/0x52a0 net/core/dev.c:4340
 dev_queue_xmit include/linux/netdevice.h:3082 [inline]
 packet_xmit+0x9c/0x6b0 net/packet/af_packet.c:276
 packet_snd net/packet/af_packet.c:3087 [inline]
 packet_sendmsg+0x8b1d/0x9f30 net/packet/af_packet.c:3119
 sock_sendmsg_nosec net/socket.c:730 [inline]
 sock_sendmsg net/socket.c:753 [inline]
 __sys_sendto+0x781/0xa30 net/socket.c:2176
 __do_sys_sendto net/socket.c:2188 [inline]
 __se_sys_sendto net/socket.c:2184 [inline]
 __ia32_sys_sendto+0x11f/0x1c0 net/socket.c:2184
 do_syscall_32_irqs_on arch/x86/entry/common.c:112 [inline]
 __do_fast_syscall_32+0xa2/0x100 arch/x86/entry/common.c:178
 do_fast_syscall_32+0x37/0x80 arch/x86/entry/common.c:203
 do_SYSENTER_32+0x1f/0x30 arch/x86/entry/common.c:246
 entry_SYSENTER_compat_after_hwframe+0x70/0x82

Uninit was created at:
 slab_post_alloc_hook+0x12f/0xb70 mm/slab.h:767
 slab_alloc_node mm/slub.c:3478 [inline]
 kmem_cache_alloc_node+0x577/0xa80 mm/slub.c:3523
 kmalloc_reserve+0x148/0x470 net/core/skbuff.c:559
 __alloc_skb+0x318/0x740 net/core/skbuff.c:644
 alloc_skb include/linux/skbuff.h:1286 [inline]
 alloc_skb_with_frags+0xc8/0xbd0 net/core/skbuff.c:6299
 sock_alloc_send_pskb+0xa80/0xbf0 net/core/sock.c:2794
 packet_alloc_skb net/packet/af_packet.c:2936 [inline]
 packet_snd net/packet/af_packet.c:3030 [inline]
 packet_sendmsg+0x70e8/0x9f30 net/packet/af_packet.c:3119
 sock_sendmsg_nosec net/socket.c:730 [inline]
 sock_sendmsg net/socket.c:753 [inline]
 __sys_sendto+0x781/0xa30 net/socket.c:2176
 __do_sys_sendto net/socket.c:2188 [inline]
 __se_sys_sendto net/socket.c:2184 [inline]
 __ia32_sys_sendto+0x11f/0x1c0 net/socket.c:2184
 do_syscall_32_irqs_on arch/x86/entry/common.c:112 [inline]
 __do_fast_syscall_32+0xa2/0x100 arch/x86/entry/common.c:178
 do_fast_syscall_32+0x37/0x80 arch/x86/entry/common.c:203
 do_SYSENTER_32+0x1f/0x30 arch/x86/entry/common.c:246
 entry_SYSENTER_compat_after_hwframe+0x70/0x82

It is because VLAN not yet supported in hsr driver. Return error
when protocol is ETH_P_8021Q in fill_frame_info() now to fix it.

Weakness: CWE-908 (Use of Uninitialized Resource)

## Which versions are affected by CVE-2023-53462?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2023-53462?

Apply the vendor's patch.

## Is CVE-2023-53462 being exploited?

There is no known exploitation of CVE-2023-53462 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-2023-53462 and fix it if it is affected.

What it is: CVE-2023-53462 is a high-severity vulnerability in Linux kernel, published on 1 Oct 2025. 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-2023-53462 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-2023-53462/ (Markdown: https://insights.sbomify.com/CVE-2023-53462/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2023-53462
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2023-53462
- OSV: https://osv.dev/vulnerability/CVE-2023-53462

---
From sbomify Insights: https://insights.sbomify.com/CVE-2023-53462/
Summaries are generated and may contain mistakes; the official description above is the record.